From 4424bfd2e54861e7061401ab8c0eae342b20daba Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Sun, 3 Oct 2021 13:00:56 +0200
Subject: [PATCH 01/29] [react] React 18 types

---
 types/react/index.d.ts    | 13 ++++---------
 types/react/test/index.ts | 12 +-----------
 types/react/test/tsx.tsx  | 16 +++++-----------
 3 files changed, 10 insertions(+), 31 deletions(-)

diff --git a/types/react/index.d.ts b/types/react/index.d.ts
index 958002af94c677..04c3f16d6e8f02 100644
--- a/types/react/index.d.ts
+++ b/types/react/index.d.ts
@@ -497,12 +497,7 @@ declare namespace React {
         forceUpdate(callback?: () => void): void;
         render(): ReactNode;
 
-        // React.Props<T> is now deprecated, which means that the `children`
-        // property is not available on `P` by default, even though you can
-        // always pass children as variadic arguments to `createElement`.
-        // In the future, if we can define its call signature conditionally
-        // on the existence of `children` in `P`, then we should remove this.
-        readonly props: Readonly<P> & Readonly<{ children?: ReactNode | undefined }>;
+        readonly props: Readonly<P>;
         state: Readonly<S>;
         /**
          * @deprecated
@@ -548,7 +543,7 @@ declare namespace React {
     type FC<P = {}> = FunctionComponent<P>;
 
     interface FunctionComponent<P = {}> {
-        (props: PropsWithChildren<P>, context?: any): ReactElement<any, any> | null;
+        (props: P, context?: any): ReactElement<any, any> | null;
         propTypes?: WeakValidationMap<P> | undefined;
         contextTypes?: ValidationMap<any> | undefined;
         defaultProps?: Partial<P> | undefined;
@@ -568,7 +563,7 @@ declare namespace React {
     type ForwardedRef<T> = ((instance: T | null) => void) | MutableRefObject<T | null> | null;
 
     interface ForwardRefRenderFunction<T, P = {}> {
-        (props: PropsWithChildren<P>, ref: ForwardedRef<T>): ReactElement | null;
+        (props: P, ref: ForwardedRef<T>): ReactElement | null;
         displayName?: string | undefined;
         // explicit rejected with `never` required due to
         // https://github.com/microsoft/TypeScript/issues/36826
@@ -862,7 +857,7 @@ declare namespace React {
 
     function memo<P extends object>(
         Component: FunctionComponent<P>,
-        propsAreEqual?: (prevProps: Readonly<PropsWithChildren<P>>, nextProps: Readonly<PropsWithChildren<P>>) => boolean
+        propsAreEqual?: (prevProps: Readonly<P>, nextProps: Readonly<P>) => boolean
     ): NamedExoticComponent<P>;
     function memo<T extends ComponentType<any>>(
         Component: T,
diff --git a/types/react/test/index.ts b/types/react/test/index.ts
index bec90d264c33b1..da05b0601ecca9 100644
--- a/types/react/test/index.ts
+++ b/types/react/test/index.ts
@@ -227,16 +227,6 @@ LegacyStatelessComponent2.defaultProps = {
     foo: 42
 };
 
-const FunctionComponent3: React.FunctionComponent<SCProps> =
-    // allows usage of props.children
-    // allows null return
-    props => props.foo ? DOM.div(null, props.foo, props.children) : null;
-
-const LegacyStatelessComponent3: React.SFC<SCProps> =
-    // allows usage of props.children
-    // allows null return
-    props => props.foo ? DOM.div(null, props.foo, props.children) : null;
-
 // allows null as props
 const FunctionComponent4: React.FunctionComponent = props => null;
 
@@ -768,7 +758,7 @@ declare var x: React.DOMElement<{
 }, Element>;
 
 // React 16 should be able to render its children directly
-class RenderChildren extends React.Component {
+class RenderChildren extends React.Component<{ children?: React.ReactNode }> {
     render() {
         const { children } = this.props;
         return children !== undefined ? children : null;
diff --git a/types/react/test/tsx.tsx b/types/react/test/tsx.tsx
index 60b7884ffa4e40..9cb826edfecdb0 100644
--- a/types/react/test/tsx.tsx
+++ b/types/react/test/tsx.tsx
@@ -13,15 +13,9 @@ FunctionComponent.defaultProps = {
 };
 <FunctionComponent />;
 <slot name="slot1"></slot>;
-
-const FunctionComponent2: React.FunctionComponent<SCProps> = ({ foo, children }) => {
-    return <div>{foo}{children}</div>;
-};
-FunctionComponent2.displayName = "FunctionComponent4";
-FunctionComponent2.defaultProps = {
-    foo: 42
-};
-<FunctionComponent2>24</FunctionComponent2>;
+// `FunctionComponent` has no `children`
+// $ExpectError
+<FunctionComponent>24</FunctionComponent>;
 
 const VoidFunctionComponent: React.VoidFunctionComponent<SCProps> = ({ foo }: SCProps) => {
     return <div>{foo}</div>;
@@ -256,8 +250,8 @@ const Memoized4 = React.memo(React.forwardRef((props: {}, ref: React.Ref<HTMLDiv
 <Memoized4 ref={memoized4Ref}/>;
 
 const Memoized5 = React.memo<{ test: boolean }>(
-    prop => <>{prop.test && prop.children}</>,
-    (prevProps, nextProps) => nextProps.test ? prevProps.children === nextProps.children : prevProps.test
+    prop => <>{prop.test}</>,
+    (prevProps, nextProps) => nextProps.test === prevProps.test
 );
 
 <Memoized5 test/>;

From c00f8f9b70c2dc4a74b43951a374436780ccc8de Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Sat, 9 Oct 2021 10:52:19 +0200
Subject: [PATCH 02/29] [react] Remove deprecated ReactType

---
 types/react/index.d.ts   |  4 ----
 types/react/test/tsx.tsx | 16 ++++++++--------
 2 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/types/react/index.d.ts b/types/react/index.d.ts
index 04c3f16d6e8f02..8ff0a9c8fb7054 100644
--- a/types/react/index.d.ts
+++ b/types/react/index.d.ts
@@ -75,10 +75,6 @@ declare namespace React {
             [K in keyof JSX.IntrinsicElements]: P extends JSX.IntrinsicElements[K] ? K : never
         }[keyof JSX.IntrinsicElements] |
         ComponentType<P>;
-    /**
-     * @deprecated Please use `ElementType`
-     */
-    type ReactType<P = any> = ElementType<P>;
     type ComponentType<P = {}> = ComponentClass<P> | FunctionComponent<P>;
 
     type JSXElementConstructor<P> =
diff --git a/types/react/test/tsx.tsx b/types/react/test/tsx.tsx
index 9cb826edfecdb0..f2d56fce65a022 100644
--- a/types/react/test/tsx.tsx
+++ b/types/react/test/tsx.tsx
@@ -420,14 +420,14 @@ type ImgPropsWithoutRef = React.ComponentPropsWithoutRef<'img'>;
 // $ExpectType false
 type ImgPropsHasRef = 'ref' extends keyof ImgPropsWithoutRef ? true : false;
 
-const HasClassName: React.ReactType<{ className?: string | undefined }> = 'a';
-const HasFoo: React.ReactType<{ foo: boolean }> = 'a'; // $ExpectError
-const HasFoo2: React.ReactType<{ foo: boolean }> = (props: { foo: boolean }) => null;
-const HasFoo3: React.ReactType<{ foo: boolean }> = (props: { foo: string }) => null; // $ExpectError
-const HasHref: React.ReactType<{ href?: string | undefined }> = 'a';
-const HasHref2: React.ReactType<{ href?: string | undefined }> = 'div'; // $ExpectError
+const HasClassName: React.ElementType<{ className?: string | undefined }> = 'a';
+const HasFoo: React.ElementType<{ foo: boolean }> = 'a'; // $ExpectError
+const HasFoo2: React.ElementType<{ foo: boolean }> = (props: { foo: boolean }) => null;
+const HasFoo3: React.ElementType<{ foo: boolean }> = (props: { foo: string }) => null; // $ExpectError
+const HasHref: React.ElementType<{ href?: string | undefined }> = 'a';
+const HasHref2: React.ElementType<{ href?: string | undefined }> = 'div'; // $ExpectError
 
-const CustomElement: React.ReactType = 'my-undeclared-element'; // $ExpectError
+const CustomElement: React.ElementType = 'my-undeclared-element'; // $ExpectError
 
 // custom elements now need to be declared as intrinsic elements
 declare global {
@@ -438,7 +438,7 @@ declare global {
     }
 }
 
-const CustomElement2: React.ReactType = 'my-declared-element';
+const CustomElement2: React.ElementType = 'my-declared-element';
 
 interface TestPropTypesProps {
     foo: string;

From 98cf44bbd31ada5b35387ab2dd6418c10e52a563 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Sat, 9 Oct 2021 11:28:10 +0200
Subject: [PATCH 03/29] [react] Remove deprecated SFCElement

---
 types/react/index.d.ts    | 5 -----
 types/react/test/index.ts | 6 ------
 2 files changed, 11 deletions(-)

diff --git a/types/react/index.d.ts b/types/react/index.d.ts
index 8ff0a9c8fb7054..daf4ec0faf71e3 100644
--- a/types/react/index.d.ts
+++ b/types/react/index.d.ts
@@ -151,11 +151,6 @@ declare namespace React {
         P = Pick<ComponentProps<T>, Exclude<keyof ComponentProps<T>, 'key' | 'ref'>>
     > extends ReactElement<P, Exclude<T, number>> { }
 
-    /**
-     * @deprecated Please use `FunctionComponentElement`
-     */
-    type SFCElement<P> = FunctionComponentElement<P>;
-
     interface FunctionComponentElement<P> extends ReactElement<P, FunctionComponent<P>> {
         ref?: ('ref' extends keyof P ? P extends { ref?: infer R | undefined } ? R : never : never) | undefined;
     }
diff --git a/types/react/test/index.ts b/types/react/test/index.ts
index da05b0601ecca9..a995dfb1269c70 100644
--- a/types/react/test/index.ts
+++ b/types/react/test/index.ts
@@ -247,8 +247,6 @@ const functionComponentFactoryElement: React.FunctionComponentElement<SCProps> =
 
 const legacyStatelessComponentFactory: React.SFCFactory<SCProps> =
     React.createFactory(FunctionComponent);
-const legacyStatelessComponentFactoryElement: React.SFCElement<SCProps> =
-    legacyStatelessComponentFactory(props);
 
 const domFactory: React.DOMFactory<React.DOMAttributes<{}>, Element> =
     React.createFactory("div");
@@ -261,8 +259,6 @@ const elementNoState: React.CElement<Props, ModernComponentNoState> = React.crea
 const elementNullProps: React.CElement<{}, ModernComponentNoPropsAndState> = React.createElement(ModernComponentNoPropsAndState, null);
 const functionComponentElement: React.FunctionComponentElement<SCProps> = React.createElement(FunctionComponent, scProps);
 const functionComponentElementNullProps: React.FunctionComponentElement<SCProps> = React.createElement(FunctionComponent4, null);
-const legacyStatelessComponentElement: React.SFCElement<SCProps> = React.createElement(FunctionComponent, scProps);
-const legacyStatelessComponentElementNullProps: React.SFCElement<SCProps> = React.createElement(FunctionComponent4, null);
 const domElement: React.DOMElement<React.HTMLAttributes<HTMLDivElement>, HTMLDivElement> = React.createElement("div");
 const domElementNullProps = React.createElement("div", null);
 const htmlElement = React.createElement("input", { type: "text" });
@@ -304,8 +300,6 @@ const clonedElement3: React.CElement<Props, ModernComponent> =
     });
 const clonedfunctionComponentElement: React.FunctionComponentElement<SCProps> =
     React.cloneElement(functionComponentElement, { foo: 44 });
-const clonedlegacyStatelessComponentElement: React.SFCElement<SCProps> =
-    React.cloneElement(legacyStatelessComponentElement, { foo: 44 });
 // Clone base DOMElement
 const clonedDOMElement: React.DOMElement<React.HTMLAttributes<HTMLDivElement>, HTMLDivElement> =
     React.cloneElement(domElement, {

From b19623fc368817725d28ef7a785d4aa19f87fa04 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Sat, 9 Oct 2021 12:00:36 +0200
Subject: [PATCH 04/29] [react] Remove deprecated StatelessComponent

---
 types/react/index.d.ts | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/types/react/index.d.ts b/types/react/index.d.ts
index daf4ec0faf71e3..2dcdd10fc0300b 100644
--- a/types/react/index.d.ts
+++ b/types/react/index.d.ts
@@ -523,14 +523,6 @@ declare namespace React {
      */
     type SFC<P = {}> = FunctionComponent<P>;
 
-    /**
-     * @deprecated as of recent React versions, function components can no
-     * longer be considered 'stateless'. Please use `FunctionComponent` instead.
-     *
-     * @see [React Hooks](https://reactjs.org/docs/hooks-intro.html)
-     */
-    type StatelessComponent<P = {}> = FunctionComponent<P>;
-
     type FC<P = {}> = FunctionComponent<P>;
 
     interface FunctionComponent<P = {}> {

From f800f4fa03a7fc7283f718b1af72fc5d072595af Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Sat, 9 Oct 2021 13:25:25 +0200
Subject: [PATCH 05/29] [react] Remove deprecated SFC

---
 types/react-dom/test-utils/index.d.ts |  4 ++--
 types/react/index.d.ts                |  8 --------
 types/react/test/index.ts             | 16 ----------------
 3 files changed, 2 insertions(+), 26 deletions(-)

diff --git a/types/react-dom/test-utils/index.d.ts b/types/react-dom/test-utils/index.d.ts
index 25bce6534a1a34..567dcf31c9ec3a 100644
--- a/types/react-dom/test-utils/index.d.ts
+++ b/types/react-dom/test-utils/index.d.ts
@@ -2,7 +2,7 @@ import {
     AbstractView, Component, ComponentClass,
     ReactElement, ReactInstance, ClassType,
     DOMElement, FunctionComponentElement, CElement,
-    ReactHTMLElement, DOMAttributes, SFC
+    ReactHTMLElement, DOMAttributes, FC
 } from 'react';
 
 import * as ReactTestUtils from ".";
@@ -194,7 +194,7 @@ export function isElementOfType<P extends DOMAttributes<{}>, T extends Element>(
  * Returns `true` if `element` is a React element whose type is of a React `componentClass`.
  */
 export function isElementOfType<P>(
-    element: ReactElement, type: SFC<P>): element is FunctionComponentElement<P>;
+    element: ReactElement, type: FC<P>): element is FunctionComponentElement<P>;
 /**
  * Returns `true` if `element` is a React element whose type is of a React `componentClass`.
  */
diff --git a/types/react/index.d.ts b/types/react/index.d.ts
index 2dcdd10fc0300b..3f96afcd4e3fa1 100644
--- a/types/react/index.d.ts
+++ b/types/react/index.d.ts
@@ -515,14 +515,6 @@ declare namespace React {
     // Class Interfaces
     // ----------------------------------------------------------------------
 
-    /**
-     * @deprecated as of recent React versions, function components can no
-     * longer be considered 'stateless'. Please use `FunctionComponent` instead.
-     *
-     * @see [React Hooks](https://reactjs.org/docs/hooks-intro.html)
-     */
-    type SFC<P = {}> = FunctionComponent<P>;
-
     type FC<P = {}> = FunctionComponent<P>;
 
     interface FunctionComponent<P = {}> {
diff --git a/types/react/test/index.ts b/types/react/test/index.ts
index a995dfb1269c70..fba058d8a32a3b 100644
--- a/types/react/test/index.ts
+++ b/types/react/test/index.ts
@@ -219,14 +219,6 @@ FunctionComponent2.defaultProps = {
     foo: 42
 };
 
-const LegacyStatelessComponent2: React.SFC<SCProps> =
-    // props is contextually typed
-    props => DOM.div(null, props.foo);
-LegacyStatelessComponent2.displayName = "LegacyStatelessComponent2";
-LegacyStatelessComponent2.defaultProps = {
-    foo: 42
-};
-
 // allows null as props
 const FunctionComponent4: React.FunctionComponent = props => null;
 
@@ -279,10 +271,6 @@ function foo3(child: React.ComponentClass<{ name: string }> | React.FunctionComp
     React.createElement(child, { name: "bar" });
 }
 
-function foo4(child: React.ComponentClass<{ name: string }> | React.SFC<{ name: string }> | string) {
-    React.createElement(child, { name: "bar" });
-}
-
 // React.cloneElement
 const clonedElement: React.CElement<Props, ModernComponent> = React.cloneElement(element, { foo: 43 });
 
@@ -770,10 +758,6 @@ React.createElement(Memoized2, { bar: 'string' });
 
 const specialSfc1: React.ExoticComponent<any> = Memoized1;
 const functionComponent: React.FunctionComponent<any> = Memoized2;
-const sfc: React.SFC<any> = Memoized2;
-// this $ExpectError is failing on TypeScript@next
-// // $ExpectError Property '$$typeof' is missing in type
-// const specialSfc2: React.SpecialSFC = props => null;
 
 const propsWithChildren: React.PropsWithChildren<Props> = {
     hello: "world",

From f219c4da4239328f0d578ad7c877596435530637 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Sun, 10 Oct 2021 12:03:12 +0200
Subject: [PATCH 06/29] [react] Remove deprecated RefForwardingComponent

---
 types/react/index.d.ts | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/types/react/index.d.ts b/types/react/index.d.ts
index 3f96afcd4e3fa1..ef7bbfc293da6a 100644
--- a/types/react/index.d.ts
+++ b/types/react/index.d.ts
@@ -552,12 +552,6 @@ declare namespace React {
         propTypes?: never | undefined;
     }
 
-    /**
-     * @deprecated Use ForwardRefRenderFunction. forwardRef doesn't accept a
-     *             "real" component.
-     */
-    interface RefForwardingComponent <T, P = {}> extends ForwardRefRenderFunction<T, P> {}
-
     interface ComponentClass<P = {}, S = ComponentState> extends StaticLifecycle<P, S> {
         new (props: P, context?: any): Component<P, S>;
         propTypes?: WeakValidationMap<P> | undefined;

From c112c30aa98c7d6858c084e1327d7a88aaff7215 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Sun, 10 Oct 2021 12:15:20 +0200
Subject: [PATCH 07/29] [react] Remove deprecated Props

---
 types/react/index.d.ts | 20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/types/react/index.d.ts b/types/react/index.d.ts
index ef7bbfc293da6a..41ca8e102d9ccf 100644
--- a/types/react/index.d.ts
+++ b/types/react/index.d.ts
@@ -1280,26 +1280,6 @@ declare namespace React {
     // Props / DOM Attributes
     // ----------------------------------------------------------------------
 
-    /**
-     * @deprecated. This was used to allow clients to pass `ref` and `key`
-     * to `createElement`, which is no longer necessary due to intersection
-     * types. If you need to declare a props object before passing it to
-     * `createElement` or a factory, use `ClassAttributes<T>`:
-     *
-     * ```ts
-     * var b: Button | null;
-     * var props: ButtonProps & ClassAttributes<Button> = {
-     *     ref: b => button = b, // ok!
-     *     label: "I'm a Button"
-     * };
-     * ```
-     */
-    interface Props<T> {
-        children?: ReactNode | undefined;
-        key?: Key | undefined;
-        ref?: LegacyRef<T> | undefined;
-    }
-
     interface HTMLProps<T> extends AllHTMLAttributes<T>, ClassAttributes<T> {
     }
 

From 2f8bc7e2372770b5e0da497ec00076841af08abc Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Sat, 8 Jan 2022 16:42:30 +0100
Subject: [PATCH 08/29] Enable noImplicit any guarantees for useCallback

---
 types/react/index.d.ts     | 6 ++++--
 types/react/test/hooks.tsx | 5 ++---
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/types/react/index.d.ts b/types/react/index.d.ts
index 41ca8e102d9ccf..7cc0aa83f50fa8 100644
--- a/types/react/index.d.ts
+++ b/types/react/index.d.ts
@@ -1073,8 +1073,10 @@ declare namespace React {
      * @version 16.8.0
      * @see https://reactjs.org/docs/hooks-reference.html#usecallback
      */
-    // TODO (TypeScript 3.0): <T extends (...args: never[]) => unknown>
-    function useCallback<T extends (...args: any[]) => any>(callback: T, deps: DependencyList): T;
+    // A specific function type would not trigger implicit any.
+    // See https://github.com/DefinitelyTyped/DefinitelyTyped/issues/52873#issuecomment-845806435 for a comparison between `Function` and more specific types.
+    // tslint:disable-next-line ban-types
+    function useCallback<T extends Function>(callback: T, deps: DependencyList): T;
     /**
      * `useMemo` will only recompute the memoized value when one of the `deps` has changed.
      *
diff --git a/types/react/test/hooks.tsx b/types/react/test/hooks.tsx
index d88143a8a5ae14..88c32eb34d3f8e 100644
--- a/types/react/test/hooks.tsx
+++ b/types/react/test/hooks.tsx
@@ -102,9 +102,8 @@ function useEveryHook(ref: React.Ref<{ id: number }>|undefined): () => boolean {
     // inline object, to (manually) check if autocomplete works
     React.useReducer(reducer, { age: 42, name: 'The Answer' });
 
-    // TODO (TypeScript 3.0): Decide whether implicit `any` should trigger `noImplicitAny` or if it should default to `unknown` or `never`
-    // https://github.com/DefinitelyTyped/DefinitelyTyped/issues/52873
-    // $ExpectType (value: any) => any
+    // Implicit any
+    // $ExpectError
     const anyCallback = React.useCallback(value => {
         // $ExpectType any
         return value;

From 2b1997438e511890f1e6db2f45203c83e84417c0 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Mon, 17 Jan 2022 22:22:25 +0100
Subject: [PATCH 09/29] Move from any to unknown where it improves type safety

---
 types/react/index.d.ts   | 6 ++----
 types/react/test/tsx.tsx | 6 +++---
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/types/react/index.d.ts b/types/react/index.d.ts
index 7cc0aa83f50fa8..e406eebbf583cd 100644
--- a/types/react/index.d.ts
+++ b/types/react/index.d.ts
@@ -467,8 +467,7 @@ declare namespace React {
          *
          * @see https://reactjs.org/docs/context.html
          */
-        // TODO (TypeScript 3.0): unknown
-        context: any;
+        context: unknown;
 
         constructor(props: Readonly<P> | P);
         /**
@@ -865,8 +864,7 @@ declare namespace React {
     // The identity check is done with the SameValue algorithm (Object.is), which is stricter than ===
     type ReducerStateWithoutAction<R extends ReducerWithoutAction<any>> =
         R extends ReducerWithoutAction<infer S> ? S : never;
-    // TODO (TypeScript 3.0): ReadonlyArray<unknown>
-    type DependencyList = ReadonlyArray<any>;
+    type DependencyList = ReadonlyArray<unknown>;
 
     // NOTE: callbacks are _only_ allowed to return either void, or a destructor.
     type EffectCallback = () => (void | Destructor);
diff --git a/types/react/test/tsx.tsx b/types/react/test/tsx.tsx
index f2d56fce65a022..75a933c5354cb7 100644
--- a/types/react/test/tsx.tsx
+++ b/types/react/test/tsx.tsx
@@ -296,9 +296,9 @@ class LegacyContext extends React.Component {
     static contextTypes = { foo: PropTypes.node.isRequired };
 
     render() {
-        // $ExpectType any
-        this.context.foo;
-        return this.context.foo;
+        // $ExpectType unknown
+        this.context;
+        return (this.context as any).foo;
     }
 }
 

From c68abcc0e756cce72573c66aaeb472764d35f183 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Mon, 17 Jan 2022 23:36:10 +0100
Subject: [PATCH 10/29] [react] Remove {} from ReactFragment

---
 types/react/index.d.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/types/react/index.d.ts b/types/react/index.d.ts
index e406eebbf583cd..2f296f6920c45b 100644
--- a/types/react/index.d.ts
+++ b/types/react/index.d.ts
@@ -228,7 +228,7 @@ declare namespace React {
      * @deprecated Use either `ReactNode[]` if you need an array or `Iterable<ReactNode>` if its passed to a host component.
      */
     interface ReactNodeArray extends ReadonlyArray<ReactNode> {}
-    type ReactFragment = {} | Iterable<ReactNode>;
+    type ReactFragment = Iterable<ReactNode>;
     type ReactNode = ReactChild | ReactFragment | ReactPortal | boolean | null | undefined;
 
     //

From 5891fd1d73c41b822d4500fd2ed0b14cd6f0f093 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Tue, 18 Jan 2022 00:51:16 +0100
Subject: [PATCH 11/29] [prop-types] Adjust for ReactFragment not including {}

---
 types/prop-types/index.d.ts | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/types/prop-types/index.d.ts b/types/prop-types/index.d.ts
index ccce1ffe5a7281..46a58eb1fec7dd 100644
--- a/types/prop-types/index.d.ts
+++ b/types/prop-types/index.d.ts
@@ -17,10 +17,9 @@ export interface ReactElementLike {
     key: string | number | null;
 }
 
-export interface ReactNodeArray extends Array<ReactNodeLike> {}
+export interface ReactNodeArray extends Iterable<ReactNodeLike> {}
 
 export type ReactNodeLike =
-    | {}
     | ReactElementLike
     | ReactNodeArray
     | string

From a2eccbe7b4ecce84a3ffd73c947831bf139d9990 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Sat, 5 Mar 2022 11:45:14 +0100
Subject: [PATCH 12/29] [react-relay] Adjust tests to not assume implicit
 children

---
 types/react-relay/test/react-relay-tests.tsx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/types/react-relay/test/react-relay-tests.tsx b/types/react-relay/test/react-relay-tests.tsx
index 41a752db2e4321..961e10e906873b 100644
--- a/types/react-relay/test/react-relay-tests.tsx
+++ b/types/react-relay/test/react-relay-tests.tsx
@@ -717,7 +717,7 @@ requestSubscription(
 ReactRelayContext.Consumer.prototype;
 ReactRelayContext.Provider.prototype;
 
-const MyRelayContextProvider: React.FunctionComponent = ({children}) => {
+const MyRelayContextProvider: React.FunctionComponent<{ children?: React.ReactNode }> = ({children}) => {
     return (
         <ReactRelayContext.Provider
             value={{

From c0e1114cfc5dcebc99ab0d380369d1e86345fa08 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Thu, 24 Mar 2022 21:04:26 +0100
Subject: [PATCH 13/29] [react-dnd-multi-backend] Patch react-dnd in test to
 use explicit children

---
 .../react-dnd-multi-backend-tests.tsx                        | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/types/react-dnd-multi-backend/react-dnd-multi-backend-tests.tsx b/types/react-dnd-multi-backend/react-dnd-multi-backend-tests.tsx
index ec3b2eef31b07c..c602deaaae1c69 100644
--- a/types/react-dnd-multi-backend/react-dnd-multi-backend-tests.tsx
+++ b/types/react-dnd-multi-backend/react-dnd-multi-backend-tests.tsx
@@ -1,10 +1,13 @@
 import * as React from 'react';
-import { DndProvider } from 'react-dnd';
+import { DndProviderProps } from 'react-dnd';
 import MultiBackend, { createTransition, TouchTransition, Backends, Preview, PreviewGenerator } from 'react-dnd-multi-backend';
 import HTML5ToTouchEsm from 'react-dnd-multi-backend/dist/esm/HTML5toTouch';
 import HTML5ToTouchCjs from 'react-dnd-multi-backend/dist/cjs/HTML5toTouch';
 import TouchBackend from 'react-dnd-touch-backend';
 
+// Legacy versions of `react-dnd` rely on implicit children of `React.FC` which was removed in `@types/react@18`
+declare const DndProvider: React.FC<React.PropsWithChildren<DndProviderProps<any, any>>>;
+
 const context = {};
 
 /**

From 2d87e8f2e6044c21ed0668a084334a286ccf2dc4 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Sat, 5 Mar 2022 11:49:25 +0100
Subject: [PATCH 14/29] [@orbit-ui/react-components] Use same types as runtime
 peer dependencies

---
 types/orbit-ui__react-components/tsconfig.json | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/types/orbit-ui__react-components/tsconfig.json b/types/orbit-ui__react-components/tsconfig.json
index e6f7c99b217388..2177c56eeca69c 100644
--- a/types/orbit-ui__react-components/tsconfig.json
+++ b/types/orbit-ui__react-components/tsconfig.json
@@ -13,7 +13,8 @@
         "forceConsistentCasingInFileNames": true,
         "jsx": "react",
         "paths": {
-            "@orbit-ui/*": ["orbit-ui__*"]
+            "@orbit-ui/*": ["orbit-ui__*"],
+            "react": ["react/v16"]
         }
     },
     "files": ["index.d.ts", "orbit-ui__react-components-tests.tsx"]

From d4098e391e42699513b3e0963c3f3e7a69f6c2ae Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Thu, 24 Mar 2022 23:01:52 +0100
Subject: [PATCH 15/29] Remove implicit children from styled-components

---
 types/styled-components/index.d.ts     | 13 +------------
 types/styled-components/test/index.tsx |  4 +---
 2 files changed, 2 insertions(+), 15 deletions(-)

diff --git a/types/styled-components/index.d.ts b/types/styled-components/index.d.ts
index 510e9a562dcb06..6ba73d81f9b26e 100644
--- a/types/styled-components/index.d.ts
+++ b/types/styled-components/index.d.ts
@@ -80,20 +80,9 @@ export type StyledComponentProps<
         ? WithOptionalTheme<
               MakeAttrsOptional<C, O, A> & MakeAttrsOptional<FAsC, O, A>,
               T
-          > &
-              WithChildrenIfReactComponentClass<C>
+          >
         : never;
 
-// Because of React typing quirks, when getting props from a React.ComponentClass,
-// we need to manually add a `children` field.
-// See https://github.com/DefinitelyTyped/DefinitelyTyped/pull/31945
-// and https://github.com/DefinitelyTyped/DefinitelyTyped/pull/32843
-type WithChildrenIfReactComponentClass<C extends string | React.ComponentType<any>> = C extends React.ComponentClass<
-    any
->
-    ? { children?: React.ReactNode | undefined }
-    : {};
-
 type StyledComponentPropsWithAs<
     C extends string | React.ComponentType<any>,
     T extends object,
diff --git a/types/styled-components/test/index.tsx b/types/styled-components/test/index.tsx
index 4c1ac577dc5bff..d441dff4f3d11f 100644
--- a/types/styled-components/test/index.tsx
+++ b/types/styled-components/test/index.tsx
@@ -1143,8 +1143,7 @@ export class WrapperClass extends React.Component<WrapperProps> {
     }
 }
 const StyledWrapperClass = styled(WrapperClass)``;
-// React.Component typings always add `children` to props, so this should accept children
-const wrapperClass = <StyledWrapperClass>Text</StyledWrapperClass>;
+const wrapperClass = <StyledWrapperClass>Text</StyledWrapperClass>; // $ExpectError
 
 export class WrapperClassFuncChild extends React.Component<WrapperProps & { children: () => any }> {
     render() {
@@ -1152,7 +1151,6 @@ export class WrapperClassFuncChild extends React.Component<WrapperProps & { chil
     }
 }
 const StyledWrapperClassFuncChild = styled(WrapperClassFuncChild)``;
-// React.Component typings always add `children` to props, so this should accept children
 const wrapperClassNoChildrenGood = <StyledWrapperClassFuncChild>{() => 'text'}</StyledWrapperClassFuncChild>;
 const wrapperClassNoChildren = <StyledWrapperClassFuncChild>Text</StyledWrapperClassFuncChild>; // $ExpectError
 

From 35f4c5efb7b442e794b990468d51f410cba32361 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Mon, 28 Mar 2022 21:46:23 +0200
Subject: [PATCH 16/29] [react-native] Drop usage of deprecated ReactType

---
 types/react-native/v0.65/index.d.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/types/react-native/v0.65/index.d.ts b/types/react-native/v0.65/index.d.ts
index 104fe5d22f25ae..7d184c2dcd339a 100644
--- a/types/react-native/v0.65/index.d.ts
+++ b/types/react-native/v0.65/index.d.ts
@@ -360,7 +360,7 @@ export interface HostComponent<P> extends Pick<React.ComponentClass<P>, Exclude<
 
 // see react-jsx.d.ts
 export function createElement<P>(
-    type: React.ReactType,
+    type: React.ElementType,
     props?: P,
     ...children: React.ReactNode[]
 ): React.ReactElement<P>;

From 1009d2a82a1e1aefd839b25f7063928cd98fa86f Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Mon, 28 Mar 2022 22:13:14 +0200
Subject: [PATCH 17/29] [styled-theming] Adjust tests

---
 .../{styled-theming-tests.ts => styled-theming-tests.tsx}    | 4 +++-
 types/styled-theming/tsconfig.json                           | 5 +++--
 2 files changed, 6 insertions(+), 3 deletions(-)
 rename types/styled-theming/{styled-theming-tests.ts => styled-theming-tests.tsx} (92%)

diff --git a/types/styled-theming/styled-theming-tests.ts b/types/styled-theming/styled-theming-tests.tsx
similarity index 92%
rename from types/styled-theming/styled-theming-tests.ts
rename to types/styled-theming/styled-theming-tests.tsx
index 23d83ce65c80d1..0f6635d8b773d1 100644
--- a/types/styled-theming/styled-theming-tests.ts
+++ b/types/styled-theming/styled-theming-tests.tsx
@@ -68,5 +68,7 @@ const Button = styled.button`
 
 const elementWithoutProp = React.createElement(Button);
 const elementWithCorrectProp = React.createElement(Button, { kind: 'secondary' });
-// $ExpectError
+// TODO(react): Unclear why this doesn't error. Probably picking an overload where excess props are fine.
 const element = React.createElement(Button, { kind: 'wrong variant' });
+// $ExpectError
+<Button kind="wrong variant" />;
diff --git a/types/styled-theming/tsconfig.json b/types/styled-theming/tsconfig.json
index 57714000f6542b..df8d334d3e48b9 100644
--- a/types/styled-theming/tsconfig.json
+++ b/types/styled-theming/tsconfig.json
@@ -11,7 +11,8 @@
         "typeRoots": ["../"],
         "types": [],
         "noEmit": true,
-        "forceConsistentCasingInFileNames": true
+        "forceConsistentCasingInFileNames": true,
+        "jsx": "react"
     },
-    "files": ["index.d.ts", "styled-theming-tests.ts"]
+    "files": ["index.d.ts", "styled-theming-tests.tsx"]
 }

From 44d4f9e02423b3eea52f32deef6e38a5b127c066 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Tue, 29 Mar 2022 19:13:00 +0200
Subject: [PATCH 18/29] Fork into v17

---
 types/react-dom/v17/index.d.ts               |  108 +
 types/react-dom/v17/node-stream/index.d.ts   |   18 +
 types/react-dom/v17/server.d.ts              |   47 +
 types/react-dom/v17/test-utils/index.d.ts    |  307 ++
 types/react-dom/v17/test/react-dom-tests.tsx |  239 ++
 types/react-dom/v17/tsconfig.json            |   36 +
 types/react-dom/v17/tslint.json              |    7 +
 types/react/v17/OTHER_FILES.txt              |    4 +
 types/react/v17/global.d.ts                  |  155 +
 types/react/v17/index.d.ts                   | 3226 ++++++++++++++++++
 types/react/v17/jsx-dev-runtime.d.ts         |    2 +
 types/react/v17/jsx-runtime.d.ts             |    2 +
 types/react/v17/package.json                 |    6 +
 types/react/v17/test/cssProperties.tsx       |   48 +
 types/react/v17/test/elementAttributes.tsx   |   98 +
 types/react/v17/test/hooks.tsx               |  254 ++
 types/react/v17/test/index.ts                |  825 +++++
 types/react/v17/test/managedAttributes.tsx   |  276 ++
 types/react/v17/test/tsx.tsx                 |  521 +++
 types/react/v17/tsconfig.json                |   34 +
 types/react/v17/tslint.json                  |   11 +
 21 files changed, 6224 insertions(+)
 create mode 100644 types/react-dom/v17/index.d.ts
 create mode 100644 types/react-dom/v17/node-stream/index.d.ts
 create mode 100644 types/react-dom/v17/server.d.ts
 create mode 100644 types/react-dom/v17/test-utils/index.d.ts
 create mode 100644 types/react-dom/v17/test/react-dom-tests.tsx
 create mode 100644 types/react-dom/v17/tsconfig.json
 create mode 100644 types/react-dom/v17/tslint.json
 create mode 100644 types/react/v17/OTHER_FILES.txt
 create mode 100644 types/react/v17/global.d.ts
 create mode 100644 types/react/v17/index.d.ts
 create mode 100644 types/react/v17/jsx-dev-runtime.d.ts
 create mode 100644 types/react/v17/jsx-runtime.d.ts
 create mode 100644 types/react/v17/package.json
 create mode 100644 types/react/v17/test/cssProperties.tsx
 create mode 100644 types/react/v17/test/elementAttributes.tsx
 create mode 100644 types/react/v17/test/hooks.tsx
 create mode 100644 types/react/v17/test/index.ts
 create mode 100644 types/react/v17/test/managedAttributes.tsx
 create mode 100644 types/react/v17/test/tsx.tsx
 create mode 100644 types/react/v17/tsconfig.json
 create mode 100644 types/react/v17/tslint.json

diff --git a/types/react-dom/v17/index.d.ts b/types/react-dom/v17/index.d.ts
new file mode 100644
index 00000000000000..d9a3f7db9aba20
--- /dev/null
+++ b/types/react-dom/v17/index.d.ts
@@ -0,0 +1,108 @@
+// Type definitions for React (react-dom) 17.0
+// Project: https://reactjs.org
+// Definitions by: Asana <https://asana.com>
+//                 AssureSign <http://www.assuresign.com>
+//                 Microsoft <https://microsoft.com>
+//                 MartynasZilinskas <https://github.com/MartynasZilinskas>
+//                 Josh Rutherford <https://github.com/theruther4d>
+//                 Jessica Franco <https://github.com/Jessidhia>
+//                 Sebastian Silbermann <https://github.com/eps1lon>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.8
+
+// NOTE: Users of the upcoming React 18 release should add a reference
+// to 'react-dom/next' in their project. See next.d.ts's top comment
+// for reference and documentation on how exactly to do it.
+
+// NOTE: Users of the `experimental` builds of React should add a reference
+// to 'react-dom/experimental' in their project. See experimental.d.ts's top comment
+// for reference and documentation on how exactly to do it.
+
+export as namespace ReactDOM;
+
+import {
+    ReactInstance, Component, ComponentState,
+    ReactElement, FunctionComponentElement, CElement,
+    DOMAttributes, DOMElement, ReactNode, ReactPortal
+} from 'react';
+
+export function findDOMNode(instance: ReactInstance | null | undefined): Element | null | Text;
+export function unmountComponentAtNode(container: Element | DocumentFragment): boolean;
+
+export function createPortal(children: ReactNode, container: Element, key?: null | string): ReactPortal;
+
+export const version: string;
+export const render: Renderer;
+export const hydrate: Renderer;
+
+export function flushSync<R>(fn: () => R): R;
+export function flushSync<A, R>(fn: (a: A) => R, a: A): R;
+
+export function unstable_batchedUpdates<A, B>(callback: (a: A, b: B) => any, a: A, b: B): void;
+export function unstable_batchedUpdates<A>(callback: (a: A) => any, a: A): void;
+export function unstable_batchedUpdates(callback: () => any): void;
+
+export function unstable_renderSubtreeIntoContainer<T extends Element>(
+    parentComponent: Component<any>,
+    element: DOMElement<DOMAttributes<T>, T>,
+    container: Element,
+    callback?: (element: T) => any): T;
+export function unstable_renderSubtreeIntoContainer<P, T extends Component<P, ComponentState>>(
+    parentComponent: Component<any>,
+    element: CElement<P, T>,
+    container: Element,
+    callback?: (component: T) => any): T;
+export function unstable_renderSubtreeIntoContainer<P>(
+    parentComponent: Component<any>,
+    element: ReactElement<P>,
+    container: Element,
+    callback?: (component?: Component<P, ComponentState> | Element) => any): Component<P, ComponentState> | Element | void;
+
+export type Container = Element | Document | DocumentFragment;
+
+export interface Renderer {
+    // Deprecated(render): The return value is deprecated.
+    // In future releases the render function's return type will be void.
+
+    <T extends Element>(
+        element: DOMElement<DOMAttributes<T>, T>,
+        container: Container| null,
+        callback?: () => void
+    ): T;
+
+    (
+        element: Array<DOMElement<DOMAttributes<any>, any>>,
+        container: Container| null,
+        callback?: () => void
+    ): Element;
+
+    (
+        element: FunctionComponentElement<any> | Array<FunctionComponentElement<any>>,
+        container: Container| null,
+        callback?: () => void
+    ): void;
+
+    <P, T extends Component<P, ComponentState>>(
+        element: CElement<P, T>,
+        container: Container| null,
+        callback?: () => void
+    ): T;
+
+    (
+        element: Array<CElement<any, Component<any, ComponentState>>>,
+        container: Container| null,
+        callback?: () => void
+    ): Component<any, ComponentState>;
+
+    <P>(
+        element: ReactElement<P>,
+        container: Container| null,
+        callback?: () => void
+    ): Component<P, ComponentState> | Element | void;
+
+    (
+        element: ReactElement[],
+        container: Container| null,
+        callback?: () => void
+    ): Component<any, ComponentState> | Element | void;
+}
diff --git a/types/react-dom/v17/node-stream/index.d.ts b/types/react-dom/v17/node-stream/index.d.ts
new file mode 100644
index 00000000000000..480392aaa4c83a
--- /dev/null
+++ b/types/react-dom/v17/node-stream/index.d.ts
@@ -0,0 +1,18 @@
+import { ReactElement } from 'react';
+
+/**
+ * Render a ReactElement to its initial HTML. This should only be used on the
+ * server.
+ * See https://facebook.github.io/react/docs/react-dom-stream.html#rendertostream
+ */
+export function renderToStream(element: ReactElement): any;
+
+/**
+ * Similar to renderToStream, except this doesn't create extra DOM attributes
+ * such as data-react-id that React uses internally.
+ * See https://facebook.github.io/react/docs/react-dom-stream.html#rendertostaticstream
+ */
+export function renderToStaticStream(element: ReactElement): any;
+export const version: string;
+
+export as namespace ReactDOMNodeStream;
diff --git a/types/react-dom/v17/server.d.ts b/types/react-dom/v17/server.d.ts
new file mode 100644
index 00000000000000..97747165a8f381
--- /dev/null
+++ b/types/react-dom/v17/server.d.ts
@@ -0,0 +1,47 @@
+// forward declarations
+declare global {
+    namespace NodeJS {
+        // tslint:disable-next-line:no-empty-interface
+        interface ReadableStream {}
+    }
+}
+
+import { ReactElement } from 'react';
+
+/**
+ * Render a React element to its initial HTML. This should only be used on the server.
+ * React will return an HTML string. You can use this method to generate HTML on the server
+ * and send the markup down on the initial request for faster page loads and to allow search
+ * engines to crawl your pages for SEO purposes.
+ *
+ * If you call `ReactDOM.hydrate()` on a node that already has this server-rendered markup,
+ * React will preserve it and only attach event handlers, allowing you
+ * to have a very performant first-load experience.
+ */
+export function renderToString(element: ReactElement): string;
+
+/**
+ * Render a React element to its initial HTML. Returns a Readable stream that outputs
+ * an HTML string. The HTML output by this stream is exactly equal to what
+ * `ReactDOMServer.renderToString()` would return.
+ */
+export function renderToNodeStream(element: ReactElement): NodeJS.ReadableStream;
+
+/**
+ * Similar to `renderToString`, except this doesn't create extra DOM attributes
+ * such as `data-reactid`, that React uses internally. This is useful if you want
+ * to use React as a simple static page generator, as stripping away the extra
+ * attributes can save lots of bytes.
+ */
+export function renderToStaticMarkup(element: ReactElement): string;
+
+/**
+ * Similar to `renderToNodeStream`, except this doesn't create extra DOM attributes
+ * such as `data-reactid`, that React uses internally. The HTML output by this stream
+ * is exactly equal to what `ReactDOMServer.renderToStaticMarkup()` would return.
+ */
+export function renderToStaticNodeStream(element: ReactElement): NodeJS.ReadableStream;
+
+export const version: string;
+
+export as namespace ReactDOMServer;
diff --git a/types/react-dom/v17/test-utils/index.d.ts b/types/react-dom/v17/test-utils/index.d.ts
new file mode 100644
index 00000000000000..567dcf31c9ec3a
--- /dev/null
+++ b/types/react-dom/v17/test-utils/index.d.ts
@@ -0,0 +1,307 @@
+import {
+    AbstractView, Component, ComponentClass,
+    ReactElement, ReactInstance, ClassType,
+    DOMElement, FunctionComponentElement, CElement,
+    ReactHTMLElement, DOMAttributes, FC
+} from 'react';
+
+import * as ReactTestUtils from ".";
+
+export {};
+
+export interface OptionalEventProperties {
+    bubbles?: boolean | undefined;
+    cancelable?: boolean | undefined;
+    currentTarget?: EventTarget | undefined;
+    defaultPrevented?: boolean | undefined;
+    eventPhase?: number | undefined;
+    isTrusted?: boolean | undefined;
+    nativeEvent?: Event | undefined;
+    preventDefault?(): void;
+    stopPropagation?(): void;
+    target?: EventTarget | undefined;
+    timeStamp?: Date | undefined;
+    type?: string | undefined;
+}
+
+export interface SyntheticEventData extends OptionalEventProperties {
+    altKey?: boolean | undefined;
+    button?: number | undefined;
+    buttons?: number | undefined;
+    clientX?: number | undefined;
+    clientY?: number | undefined;
+    changedTouches?: TouchList | undefined;
+    charCode?: number | undefined;
+    clipboardData?: DataTransfer | undefined;
+    ctrlKey?: boolean | undefined;
+    deltaMode?: number | undefined;
+    deltaX?: number | undefined;
+    deltaY?: number | undefined;
+    deltaZ?: number | undefined;
+    detail?: number | undefined;
+    getModifierState?(key: string): boolean;
+    key?: string | undefined;
+    keyCode?: number | undefined;
+    locale?: string | undefined;
+    location?: number | undefined;
+    metaKey?: boolean | undefined;
+    pageX?: number | undefined;
+    pageY?: number | undefined;
+    relatedTarget?: EventTarget | undefined;
+    repeat?: boolean | undefined;
+    screenX?: number | undefined;
+    screenY?: number | undefined;
+    shiftKey?: boolean | undefined;
+    targetTouches?: TouchList | undefined;
+    touches?: TouchList | undefined;
+    view?: AbstractView | undefined;
+    which?: number | undefined;
+}
+
+export type EventSimulator = (element: Element | Component<any>, eventData?: SyntheticEventData) => void;
+
+export interface MockedComponentClass {
+    new (props: any): any;
+}
+
+export interface ShallowRenderer {
+    /**
+     * After `shallowRenderer.render()` has been called, returns shallowly rendered output.
+     */
+    getRenderOutput<E extends ReactElement>(): E;
+    /**
+     * Similar to `ReactDOM.render` but it doesn't require DOM and only renders a single level deep.
+     */
+    render(element: ReactElement, context?: any): void;
+    unmount(): void;
+}
+
+/**
+ * Simulate an event dispatch on a DOM node with optional `eventData` event data.
+ * `Simulate` has a method for every event that React understands.
+ */
+export namespace Simulate {
+    const abort: EventSimulator;
+    const animationEnd: EventSimulator;
+    const animationIteration: EventSimulator;
+    const animationStart: EventSimulator;
+    const blur: EventSimulator;
+    const canPlay: EventSimulator;
+    const canPlayThrough: EventSimulator;
+    const change: EventSimulator;
+    const click: EventSimulator;
+    const compositionEnd: EventSimulator;
+    const compositionStart: EventSimulator;
+    const compositionUpdate: EventSimulator;
+    const contextMenu: EventSimulator;
+    const copy: EventSimulator;
+    const cut: EventSimulator;
+    const doubleClick: EventSimulator;
+    const drag: EventSimulator;
+    const dragEnd: EventSimulator;
+    const dragEnter: EventSimulator;
+    const dragExit: EventSimulator;
+    const dragLeave: EventSimulator;
+    const dragOver: EventSimulator;
+    const dragStart: EventSimulator;
+    const drop: EventSimulator;
+    const durationChange: EventSimulator;
+    const emptied: EventSimulator;
+    const encrypted: EventSimulator;
+    const ended: EventSimulator;
+    const error: EventSimulator;
+    const focus: EventSimulator;
+    const input: EventSimulator;
+    const invalid: EventSimulator;
+    const keyDown: EventSimulator;
+    const keyPress: EventSimulator;
+    const keyUp: EventSimulator;
+    const load: EventSimulator;
+    const loadStart: EventSimulator;
+    const loadedData: EventSimulator;
+    const loadedMetadata: EventSimulator;
+    const mouseDown: EventSimulator;
+    const mouseEnter: EventSimulator;
+    const mouseLeave: EventSimulator;
+    const mouseMove: EventSimulator;
+    const mouseOut: EventSimulator;
+    const mouseOver: EventSimulator;
+    const mouseUp: EventSimulator;
+    const paste: EventSimulator;
+    const pause: EventSimulator;
+    const play: EventSimulator;
+    const playing: EventSimulator;
+    const progress: EventSimulator;
+    const rateChange: EventSimulator;
+    const scroll: EventSimulator;
+    const seeked: EventSimulator;
+    const seeking: EventSimulator;
+    const select: EventSimulator;
+    const stalled: EventSimulator;
+    const submit: EventSimulator;
+    const suspend: EventSimulator;
+    const timeUpdate: EventSimulator;
+    const touchCancel: EventSimulator;
+    const touchEnd: EventSimulator;
+    const touchMove: EventSimulator;
+    const touchStart: EventSimulator;
+    const transitionEnd: EventSimulator;
+    const volumeChange: EventSimulator;
+    const waiting: EventSimulator;
+    const wheel: EventSimulator;
+}
+
+/**
+ * Render a React element into a detached DOM node in the document. __This function requires a DOM__.
+ */
+export function renderIntoDocument<T extends Element>(
+    element: DOMElement<any, T>): T;
+export function renderIntoDocument(
+    element: FunctionComponentElement<any>): void;
+// If we replace `P` with `any` in this overload, then some tests fail because
+// calls to `renderIntoDocument` choose the last overload on the
+// subtype-relation pass and get an undesirably broad return type.  Using `P`
+// allows this overload to match on the subtype-relation pass.
+export function renderIntoDocument<P, T extends Component<P>>(
+    element: CElement<P, T>): T;
+export function renderIntoDocument<P>(
+    element: ReactElement<P>): Component<P> | Element | void;
+
+/**
+ * Pass a mocked component module to this method to augment it with useful methods that allow it to
+ * be used as a dummy React component. Instead of rendering as usual, the component will become
+ * a simple `<div>` (or other tag if `mockTagName` is provided) containing any provided children.
+ */
+export function mockComponent(
+    mocked: MockedComponentClass, mockTagName?: string): typeof ReactTestUtils;
+
+/**
+ * Returns `true` if `element` is any React element.
+ */
+export function isElement(element: any): boolean;
+
+/**
+ * Returns `true` if `element` is a React element whose type is of a React `componentClass`.
+ */
+export function isElementOfType<T extends HTMLElement>(
+    element: ReactElement, type: string): element is ReactHTMLElement<T>;
+/**
+ * Returns `true` if `element` is a React element whose type is of a React `componentClass`.
+ */
+export function isElementOfType<P extends DOMAttributes<{}>, T extends Element>(
+    element: ReactElement, type: string): element is DOMElement<P, T>;
+/**
+ * Returns `true` if `element` is a React element whose type is of a React `componentClass`.
+ */
+export function isElementOfType<P>(
+    element: ReactElement, type: FC<P>): element is FunctionComponentElement<P>;
+/**
+ * Returns `true` if `element` is a React element whose type is of a React `componentClass`.
+ */
+export function isElementOfType<P, T extends Component<P>, C extends ComponentClass<P>>(
+    element: ReactElement, type: ClassType<P, T, C>): element is CElement<P, T>;
+
+/**
+ * Returns `true` if `instance` is a DOM component (such as a `<div>` or `<span>`).
+ */
+export function isDOMComponent(instance: ReactInstance): instance is Element;
+/**
+ * Returns `true` if `instance` is a user-defined component, such as a class or a function.
+ */
+export function isCompositeComponent(instance: ReactInstance): instance is Component<any>;
+/**
+ * Returns `true` if `instance` is a component whose type is of a React `componentClass`.
+ */
+export function isCompositeComponentWithType<T extends Component<any>, C extends ComponentClass<any>>(
+    instance: ReactInstance, type: ClassType<any, T, C>): boolean;
+
+/**
+ * Traverse all components in `tree` and accumulate all components where
+ * `test(component)` is `true`. This is not that useful on its own, but it's used
+ * as a primitive for other test utils.
+ */
+export function findAllInRenderedTree(
+    root: Component<any>,
+    fn: (i: ReactInstance) => boolean): ReactInstance[];
+
+/**
+ * Finds all DOM elements of components in the rendered tree that are
+ * DOM components with the class name matching `className`.
+ */
+export function scryRenderedDOMComponentsWithClass(
+    root: Component<any>,
+    className: string): Element[];
+/**
+ * Like `scryRenderedDOMComponentsWithClass()` but expects there to be one result,
+ * and returns that one result, or throws exception if there is any other
+ * number of matches besides one.
+ */
+export function findRenderedDOMComponentWithClass(
+    root: Component<any>,
+    className: string): Element;
+
+/**
+ * Finds all DOM elements of components in the rendered tree that are
+ * DOM components with the tag name matching `tagName`.
+ */
+export function scryRenderedDOMComponentsWithTag(
+    root: Component<any>,
+    tagName: string): Element[];
+/**
+ * Like `scryRenderedDOMComponentsWithTag()` but expects there to be one result,
+ * and returns that one result, or throws exception if there is any other
+ * number of matches besides one.
+ */
+export function findRenderedDOMComponentWithTag(
+    root: Component<any>,
+    tagName: string): Element;
+
+/**
+ * Finds all instances of components with type equal to `componentClass`.
+ */
+export function scryRenderedComponentsWithType<T extends Component<any>, C extends ComponentClass<any>>(
+    root: Component<any>,
+    type: ClassType<any, T, C>): T[];
+
+/**
+ * Same as `scryRenderedComponentsWithType()` but expects there to be one result
+ * and returns that one result, or throws exception if there is any other
+ * number of matches besides one.
+ */
+export function findRenderedComponentWithType<T extends Component<any>, C extends ComponentClass<any>>(
+    root: Component<any>,
+    type: ClassType<any, T, C>): T;
+
+/**
+ * Call this in your tests to create a shallow renderer.
+ */
+export function createRenderer(): ShallowRenderer;
+
+/**
+ * Wrap any code rendering and triggering updates to your components into `act()` calls.
+ *
+ * Ensures that the behavior in your tests matches what happens in the browser
+ * more closely by executing pending `useEffect`s before returning. This also
+ * reduces the amount of re-renders done.
+ *
+ * @param callback A synchronous, void callback that will execute as a single, complete React commit.
+ *
+ * @see https://reactjs.org/blog/2019/02/06/react-v16.8.0.html#testing-hooks
+ */
+// NOTES
+// - the order of these signatures matters - typescript will check the signatures in source order.
+//   If the `() => VoidOrUndefinedOnly` signature is first, it'll erroneously match a Promise returning function for users with
+//   `strictNullChecks: false`.
+// - VoidOrUndefinedOnly is there to forbid any non-void return values for users with `strictNullChecks: true`
+declare const UNDEFINED_VOID_ONLY: unique symbol;
+// tslint:disable-next-line: void-return
+type VoidOrUndefinedOnly = void | { [UNDEFINED_VOID_ONLY]: never };
+export function act(callback: () => Promise<void>): Promise<undefined>;
+export function act(callback: () => VoidOrUndefinedOnly): void;
+
+// Intentionally doesn't extend PromiseLike<never>.
+// Ideally this should be as hard to accidentally use as possible.
+export interface DebugPromiseLike {
+    // the actual then() in here is 0-ary, but that doesn't count as a PromiseLike.
+    then(onfulfilled: (value: never) => never, onrejected: (reason: never) => never): never;
+}
diff --git a/types/react-dom/v17/test/react-dom-tests.tsx b/types/react-dom/v17/test/react-dom-tests.tsx
new file mode 100644
index 00000000000000..2ec52495aa930a
--- /dev/null
+++ b/types/react-dom/v17/test/react-dom-tests.tsx
@@ -0,0 +1,239 @@
+import * as React from 'react';
+import * as ReactDOM from 'react-dom';
+import * as ReactDOMServer from 'react-dom/server';
+import * as ReactDOMNodeStream from 'react-dom/node-stream';
+import * as ReactTestUtils from 'react-dom/test-utils';
+
+declare function describe(desc: string, f: () => void): void;
+declare function it(desc: string, f: () => void): void;
+
+class TestComponent extends React.Component<{x: string}> { }
+
+describe('ReactDOM', () => {
+    it('render', () => {
+        const rootElement = document.createElement('div');
+        ReactDOM.render(React.createElement('div'), rootElement);
+        ReactDOM.render(React.createElement('div'), document.createDocumentFragment());
+        ReactDOM.render(React.createElement('div'), document);
+    });
+
+    it('hydrate', () => {
+        const rootElement = document.createElement('div');
+        ReactDOM.hydrate(React.createElement('div'), rootElement);
+        ReactDOM.hydrate(React.createElement('div'), document.createDocumentFragment());
+        ReactDOM.hydrate(React.createElement('div'), document);
+    });
+
+    it('unmounts', () => {
+        const rootElement = document.createElement('div');
+        ReactDOM.render(React.createElement('div'), rootElement);
+        ReactDOM.unmountComponentAtNode(rootElement);
+    });
+
+    it('works with document fragments', () => {
+        const fragment = document.createDocumentFragment();
+        ReactDOM.render(React.createElement('div'), fragment);
+        ReactDOM.unmountComponentAtNode(fragment);
+    });
+
+    it('find dom node', () => {
+        const rootElement = document.createElement('div');
+        ReactDOM.render(React.createElement('div'), rootElement);
+        ReactDOM.findDOMNode(rootElement);
+        ReactDOM.findDOMNode(null);
+        ReactDOM.findDOMNode(undefined);
+    });
+
+    it('createPortal', () => {
+        const rootElement = document.createElement('div');
+        const portalTarget = document.createElement('div');
+
+        class ClassComponent extends React.Component {
+            render() {
+                return ReactDOM.createPortal(<div />, portalTarget);
+            }
+        }
+
+        ReactDOM.createPortal(<div />, document.createElement('div'));
+        ReactDOM.createPortal(<div />, document.createElement('div'), null);
+        ReactDOM.createPortal(<div />, document.createElement('div'), 'key');
+
+        ReactDOM.createPortal(React.createElement('div'), document.createElement('div'));
+        ReactDOM.createPortal(React.createElement('div'), document.createElement('div'), null);
+        ReactDOM.createPortal(React.createElement('div'), document.createElement('div'), 'key');
+
+        ReactDOM.render(<ClassComponent />, rootElement);
+    });
+
+    it('flushSync', () => {
+        // $ExpectType void
+        ReactDOM.flushSync(() => {});
+        // $ExpectType number
+        ReactDOM.flushSync(() => 42);
+        // $ExpectType number
+        ReactDOM.flushSync(() => 42, 'not used');
+        // $ExpectType number
+        ReactDOM.flushSync((a: string) => 42, 'not used');
+        // $ExpectError
+        ReactDOM.flushSync((a: string) => 42);
+        // $ExpectError
+        ReactDOM.flushSync((a: string) => 42, 100);
+    });
+});
+
+describe('ReactDOMServer', () => {
+    it('renderToString', () => {
+        const content: string = ReactDOMServer.renderToString(React.createElement('div'));
+    });
+
+    it('renderToStaticMarkup', () => {
+        const content: string = ReactDOMServer.renderToStaticMarkup(React.createElement('div'));
+    });
+});
+
+describe('ReactDOMNodeStream', () => {
+    it('renderToStream', () => {
+        const content: any = ReactDOMNodeStream.renderToStream(React.createElement('div'));
+    });
+
+    it('renderToStaticStream', () => {
+        const content: any = ReactDOMNodeStream.renderToStaticStream(React.createElement('div'));
+    });
+});
+
+describe('React dom test utils', () => {
+    it('Simulate', () => {
+        const element = document.createElement('div');
+        const dom = ReactDOM.render(
+            React.createElement('input', { type: 'text' }),
+            element
+        ) as Element;
+        const node = ReactDOM.findDOMNode(dom) as HTMLInputElement;
+
+        node.value = 'giraffe';
+        ReactTestUtils.Simulate.change(node);
+        ReactTestUtils.Simulate.keyDown(node, { key: "Enter", keyCode: 13, which: 13 });
+    });
+
+    it('renderIntoDocument', () => {
+        const element = React.createElement('input', { type: 'text' });
+        ReactTestUtils.renderIntoDocument(element);
+    });
+
+    it('mockComponent', () => {
+        ReactTestUtils.mockComponent(TestComponent, 'div');
+    });
+
+    it('isElement', () => {
+        const element = React.createElement(TestComponent);
+        const isReactElement: boolean = ReactTestUtils.isElement(element);
+    });
+
+    it('isElementOfType', () => {
+        const element = React.createElement(TestComponent);
+        const isReactElement: boolean = ReactTestUtils.isElementOfType(element, TestComponent);
+    });
+
+    it('isDOMComponent', () => {
+        const element = React.createElement('div');
+        const instance = ReactTestUtils.renderIntoDocument(element) as HTMLDivElement;
+        const isDOMElement: boolean = ReactTestUtils.isDOMComponent(instance);
+    });
+
+    it('isCompositeComponent', () => {
+        const element = React.createElement(TestComponent);
+        const instance: TestComponent = ReactTestUtils.renderIntoDocument(element);
+        const isCompositeComponent: boolean = ReactTestUtils.isCompositeComponent(instance);
+    });
+
+    it('isCompositeComponentWithType', () => {
+        const element = React.createElement(TestComponent);
+        const instance: TestComponent = ReactTestUtils.renderIntoDocument(element);
+        const isCompositeComponent: boolean = ReactTestUtils.isCompositeComponentWithType(instance, TestComponent);
+    });
+
+    it('findAllInRenderedTree', () => {
+        const component = ReactTestUtils.renderIntoDocument(React.createElement(TestComponent));
+        ReactTestUtils.findAllInRenderedTree(component, (i: React.ReactInstance) => true);
+    });
+
+    it('scryRenderedDOMComponentsWithClass', () => {
+        const component = ReactTestUtils.renderIntoDocument(React.createElement(TestComponent));
+        ReactTestUtils.scryRenderedDOMComponentsWithClass(component, 'class');
+    });
+
+    it('findRenderedDOMComponentWithClass', () => {
+        const component = ReactTestUtils.renderIntoDocument(React.createElement(TestComponent));
+        ReactTestUtils.findRenderedDOMComponentWithClass(component, 'class');
+    });
+
+    it('scryRenderedDOMComponentsWithTag', () => {
+        const component = ReactTestUtils.renderIntoDocument(React.createElement(TestComponent));
+        ReactTestUtils.scryRenderedDOMComponentsWithTag(component, 'div');
+    });
+
+    it('findRenderedDOMComponentWithTag', () => {
+        const component = ReactTestUtils.renderIntoDocument(React.createElement(TestComponent));
+        ReactTestUtils.findRenderedDOMComponentWithTag(component, 'tag');
+    });
+
+    it('scryRenderedComponentsWithType', () => {
+        const component = ReactTestUtils.renderIntoDocument(React.createElement(TestComponent));
+        ReactTestUtils.scryRenderedComponentsWithType(component, TestComponent);
+    });
+
+    it('findRenderedComponentWithType', () => {
+        const component = ReactTestUtils.renderIntoDocument(React.createElement(TestComponent));
+        ReactTestUtils.findRenderedComponentWithType(component, TestComponent);
+    });
+
+    describe('Shallow Rendering', () => {
+        it('createRenderer', () => {
+            const component = React.createElement(TestComponent);
+            const shallowRenderer = ReactTestUtils.createRenderer();
+        });
+
+        it('shallowRenderer.render', () => {
+            const component = React.createElement(TestComponent);
+            const shallowRenderer = ReactTestUtils.createRenderer();
+            shallowRenderer.render(component);
+        });
+
+        it('shallowRenderer.getRenderOutput', () => {
+            const component = React.createElement(TestComponent);
+            const shallowRenderer = ReactTestUtils.createRenderer();
+            shallowRenderer.getRenderOutput();
+        });
+    });
+
+    describe('act', () => {
+        describe('with sync callback', () => {
+            it('accepts a callback that is void', () => {
+                ReactTestUtils.act(() => {});
+            });
+            it('rejects a callback that returns null', () => {
+                // $ExpectError
+                ReactTestUtils.act(() => null);
+            });
+            it('returns a type that is not Promise-like', () => {
+                // tslint:disable-next-line no-void-expression
+                const result = ReactTestUtils.act(() => {});
+                // $ExpectError
+                result.then((x) => {});
+            });
+        });
+        describe('with async callback', () => {
+            it('accepts a callback that is void', async () => {
+                await ReactTestUtils.act(async () => {});
+            });
+            it('rejects a callback that returns a value', async () => {
+                // $ExpectError
+                await ReactTestUtils.act(async () => null);
+            });
+            it('returns a Promise-like', () => {
+                const result = ReactTestUtils.act(async () => {});
+                result.then((x) => {});
+            });
+        });
+    });
+});
diff --git a/types/react-dom/v17/tsconfig.json b/types/react-dom/v17/tsconfig.json
new file mode 100644
index 00000000000000..dbd185b2e679b1
--- /dev/null
+++ b/types/react-dom/v17/tsconfig.json
@@ -0,0 +1,36 @@
+{
+    "files": [
+        "index.d.ts",
+        "test/react-dom-tests.tsx"
+    ],
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6",
+            "dom"
+        ],
+        "paths": {
+            "react": [
+                "react/v17"
+            ],
+            "react-dom": [
+                "react-dom/v17"
+            ],
+            "react-dom/*": [
+                "react-dom/v17/*"
+            ]
+        },
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "strictFunctionTypes": true,
+        "baseUrl": "../../",
+        "typeRoots": [
+            "../../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true,
+        "jsx": "preserve"
+    }
+}
diff --git a/types/react-dom/v17/tslint.json b/types/react-dom/v17/tslint.json
new file mode 100644
index 00000000000000..df0e470257e793
--- /dev/null
+++ b/types/react-dom/v17/tslint.json
@@ -0,0 +1,7 @@
+{
+    "extends": "@definitelytyped/dtslint/dt.json",
+    "rules": {
+        "dt-header": false,
+        "no-unnecessary-generics": false
+    }
+}
diff --git a/types/react/v17/OTHER_FILES.txt b/types/react/v17/OTHER_FILES.txt
new file mode 100644
index 00000000000000..a4d354fcba50c4
--- /dev/null
+++ b/types/react/v17/OTHER_FILES.txt
@@ -0,0 +1,4 @@
+next.d.ts
+experimental.d.ts
+jsx-dev-runtime.d.ts
+jsx-runtime.d.ts
diff --git a/types/react/v17/global.d.ts b/types/react/v17/global.d.ts
new file mode 100644
index 00000000000000..0799137c8cf025
--- /dev/null
+++ b/types/react/v17/global.d.ts
@@ -0,0 +1,155 @@
+/*
+React projects that don't include the DOM library need these interfaces to compile.
+React Native applications use React, but there is no DOM available. The JavaScript runtime
+is ES6/ES2015 only. These definitions allow such projects to compile with only `--lib ES6`.
+
+Warning: all of these interfaces are empty. If you want type definitions for various properties
+(such as HTMLInputElement.prototype.value), you need to add `--lib DOM` (via command line or tsconfig.json).
+*/
+
+interface Event { }
+interface AnimationEvent extends Event { }
+interface ClipboardEvent extends Event { }
+interface CompositionEvent extends Event { }
+interface DragEvent extends Event { }
+interface FocusEvent extends Event { }
+interface KeyboardEvent extends Event { }
+interface MouseEvent extends Event { }
+interface TouchEvent extends Event { }
+interface PointerEvent extends Event { }
+interface TransitionEvent extends Event { }
+interface UIEvent extends Event { }
+interface WheelEvent extends Event { }
+
+interface EventTarget { }
+interface Document { }
+interface DataTransfer { }
+interface StyleMedia { }
+
+interface Element { }
+interface DocumentFragment { }
+
+interface HTMLElement extends Element { }
+interface HTMLAnchorElement extends HTMLElement { }
+interface HTMLAreaElement extends HTMLElement { }
+interface HTMLAudioElement extends HTMLElement { }
+interface HTMLBaseElement extends HTMLElement { }
+interface HTMLBodyElement extends HTMLElement { }
+interface HTMLBRElement extends HTMLElement { }
+interface HTMLButtonElement extends HTMLElement { }
+interface HTMLCanvasElement extends HTMLElement { }
+interface HTMLDataElement extends HTMLElement { }
+interface HTMLDataListElement extends HTMLElement { }
+interface HTMLDetailsElement extends HTMLElement { }
+interface HTMLDialogElement extends HTMLElement { }
+interface HTMLDivElement extends HTMLElement { }
+interface HTMLDListElement extends HTMLElement { }
+interface HTMLEmbedElement extends HTMLElement { }
+interface HTMLFieldSetElement extends HTMLElement { }
+interface HTMLFormElement extends HTMLElement { }
+interface HTMLHeadingElement extends HTMLElement { }
+interface HTMLHeadElement extends HTMLElement { }
+interface HTMLHRElement extends HTMLElement { }
+interface HTMLHtmlElement extends HTMLElement { }
+interface HTMLIFrameElement extends HTMLElement { }
+interface HTMLImageElement extends HTMLElement { }
+interface HTMLInputElement extends HTMLElement { }
+interface HTMLModElement extends HTMLElement { }
+interface HTMLLabelElement extends HTMLElement { }
+interface HTMLLegendElement extends HTMLElement { }
+interface HTMLLIElement extends HTMLElement { }
+interface HTMLLinkElement extends HTMLElement { }
+interface HTMLMapElement extends HTMLElement { }
+interface HTMLMetaElement extends HTMLElement { }
+interface HTMLMeterElement extends HTMLElement { }
+interface HTMLObjectElement extends HTMLElement { }
+interface HTMLOListElement extends HTMLElement { }
+interface HTMLOptGroupElement extends HTMLElement { }
+interface HTMLOptionElement extends HTMLElement { }
+interface HTMLOutputElement extends HTMLElement { }
+interface HTMLParagraphElement extends HTMLElement { }
+interface HTMLParamElement extends HTMLElement { }
+interface HTMLPreElement extends HTMLElement { }
+interface HTMLProgressElement extends HTMLElement { }
+interface HTMLQuoteElement extends HTMLElement { }
+interface HTMLSlotElement extends HTMLElement { }
+interface HTMLScriptElement extends HTMLElement { }
+interface HTMLSelectElement extends HTMLElement { }
+interface HTMLSourceElement extends HTMLElement { }
+interface HTMLSpanElement extends HTMLElement { }
+interface HTMLStyleElement extends HTMLElement { }
+interface HTMLTableElement extends HTMLElement { }
+interface HTMLTableColElement extends HTMLElement { }
+interface HTMLTableDataCellElement extends HTMLElement { }
+interface HTMLTableHeaderCellElement extends HTMLElement { }
+interface HTMLTableRowElement extends HTMLElement { }
+interface HTMLTableSectionElement extends HTMLElement { }
+interface HTMLTemplateElement extends HTMLElement { }
+interface HTMLTextAreaElement extends HTMLElement { }
+interface HTMLTimeElement extends HTMLElement { }
+interface HTMLTitleElement extends HTMLElement { }
+interface HTMLTrackElement extends HTMLElement { }
+interface HTMLUListElement extends HTMLElement { }
+interface HTMLVideoElement extends HTMLElement { }
+interface HTMLWebViewElement extends HTMLElement { }
+
+interface SVGElement extends Element { }
+interface SVGSVGElement extends SVGElement { }
+interface SVGCircleElement extends SVGElement { }
+interface SVGClipPathElement extends SVGElement { }
+interface SVGDefsElement extends SVGElement { }
+interface SVGDescElement extends SVGElement { }
+interface SVGEllipseElement extends SVGElement { }
+interface SVGFEBlendElement extends SVGElement { }
+interface SVGFEColorMatrixElement extends SVGElement { }
+interface SVGFEComponentTransferElement extends SVGElement { }
+interface SVGFECompositeElement extends SVGElement { }
+interface SVGFEConvolveMatrixElement extends SVGElement { }
+interface SVGFEDiffuseLightingElement extends SVGElement { }
+interface SVGFEDisplacementMapElement extends SVGElement { }
+interface SVGFEDistantLightElement extends SVGElement { }
+interface SVGFEDropShadowElement extends SVGElement { }
+interface SVGFEFloodElement extends SVGElement { }
+interface SVGFEFuncAElement extends SVGElement { }
+interface SVGFEFuncBElement extends SVGElement { }
+interface SVGFEFuncGElement extends SVGElement { }
+interface SVGFEFuncRElement extends SVGElement { }
+interface SVGFEGaussianBlurElement extends SVGElement { }
+interface SVGFEImageElement extends SVGElement { }
+interface SVGFEMergeElement extends SVGElement { }
+interface SVGFEMergeNodeElement extends SVGElement { }
+interface SVGFEMorphologyElement extends SVGElement { }
+interface SVGFEOffsetElement extends SVGElement { }
+interface SVGFEPointLightElement extends SVGElement { }
+interface SVGFESpecularLightingElement extends SVGElement { }
+interface SVGFESpotLightElement extends SVGElement { }
+interface SVGFETileElement extends SVGElement { }
+interface SVGFETurbulenceElement extends SVGElement { }
+interface SVGFilterElement extends SVGElement { }
+interface SVGForeignObjectElement extends SVGElement { }
+interface SVGGElement extends SVGElement { }
+interface SVGImageElement extends SVGElement { }
+interface SVGLineElement extends SVGElement { }
+interface SVGLinearGradientElement extends SVGElement { }
+interface SVGMarkerElement extends SVGElement { }
+interface SVGMaskElement extends SVGElement { }
+interface SVGMetadataElement extends SVGElement { }
+interface SVGPathElement extends SVGElement { }
+interface SVGPatternElement extends SVGElement { }
+interface SVGPolygonElement extends SVGElement { }
+interface SVGPolylineElement extends SVGElement { }
+interface SVGRadialGradientElement extends SVGElement { }
+interface SVGRectElement extends SVGElement { }
+interface SVGStopElement extends SVGElement { }
+interface SVGSwitchElement extends SVGElement { }
+interface SVGSymbolElement extends SVGElement { }
+interface SVGTextElement extends SVGElement { }
+interface SVGTextPathElement extends SVGElement { }
+interface SVGTSpanElement extends SVGElement { }
+interface SVGUseElement extends SVGElement { }
+interface SVGViewElement extends SVGElement { }
+
+interface Text { }
+interface TouchList { }
+interface WebGLRenderingContext { }
+interface WebGL2RenderingContext { }
diff --git a/types/react/v17/index.d.ts b/types/react/v17/index.d.ts
new file mode 100644
index 00000000000000..2f296f6920c45b
--- /dev/null
+++ b/types/react/v17/index.d.ts
@@ -0,0 +1,3226 @@
+// Type definitions for React 17.0
+// Project: http://facebook.github.io/react/
+// Definitions by: Asana <https://asana.com>
+//                 AssureSign <http://www.assuresign.com>
+//                 Microsoft <https://microsoft.com>
+//                 John Reilly <https://github.com/johnnyreilly>
+//                 Benoit Benezech <https://github.com/bbenezech>
+//                 Patricio Zavolinsky <https://github.com/pzavolinsky>
+//                 Eric Anderson <https://github.com/ericanderson>
+//                 Dovydas Navickas <https://github.com/DovydasNavickas>
+//                 Josh Rutherford <https://github.com/theruther4d>
+//                 Guilherme Hübner <https://github.com/guilhermehubner>
+//                 Ferdy Budhidharma <https://github.com/ferdaber>
+//                 Johann Rakotoharisoa <https://github.com/jrakotoharisoa>
+//                 Olivier Pascal <https://github.com/pascaloliv>
+//                 Martin Hochel <https://github.com/hotell>
+//                 Frank Li <https://github.com/franklixuefei>
+//                 Jessica Franco <https://github.com/Jessidhia>
+//                 Saransh Kataria <https://github.com/saranshkataria>
+//                 Kanitkorn Sujautra <https://github.com/lukyth>
+//                 Sebastian Silbermann <https://github.com/eps1lon>
+//                 Kyle Scully <https://github.com/zieka>
+//                 Cong Zhang <https://github.com/dancerphil>
+//                 Dimitri Mitropoulos <https://github.com/dimitropoulos>
+//                 JongChan Choi <https://github.com/disjukr>
+//                 Victor Magalhães <https://github.com/vhfmag>
+//                 Dale Tan <https://github.com/hellatan>
+//                 Priyanshu Rav <https://github.com/priyanshurav>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.8
+
+// NOTE: Users of the upcoming React 18 release should add a reference
+// to 'react/next' in their project. See next.d.ts's top comment
+// for reference and documentation on how exactly to do it.
+
+// NOTE: Users of the `experimental` builds of React should add a reference
+// to 'react/experimental' in their project. See experimental.d.ts's top comment
+// for reference and documentation on how exactly to do it.
+
+/// <reference path="global.d.ts" />
+
+import * as CSS from 'csstype';
+import * as PropTypes from 'prop-types';
+import { Interaction as SchedulerInteraction } from 'scheduler/tracing';
+
+type NativeAnimationEvent = AnimationEvent;
+type NativeClipboardEvent = ClipboardEvent;
+type NativeCompositionEvent = CompositionEvent;
+type NativeDragEvent = DragEvent;
+type NativeFocusEvent = FocusEvent;
+type NativeKeyboardEvent = KeyboardEvent;
+type NativeMouseEvent = MouseEvent;
+type NativeTouchEvent = TouchEvent;
+type NativePointerEvent = PointerEvent;
+type NativeTransitionEvent = TransitionEvent;
+type NativeUIEvent = UIEvent;
+type NativeWheelEvent = WheelEvent;
+type Booleanish = boolean | 'true' | 'false';
+
+declare const UNDEFINED_VOID_ONLY: unique symbol;
+// Destructors are only allowed to return void.
+type Destructor = () => void | { [UNDEFINED_VOID_ONLY]: never };
+
+// tslint:disable-next-line:export-just-namespace
+export = React;
+export as namespace React;
+
+declare namespace React {
+    //
+    // React Elements
+    // ----------------------------------------------------------------------
+
+    type ElementType<P = any> =
+        {
+            [K in keyof JSX.IntrinsicElements]: P extends JSX.IntrinsicElements[K] ? K : never
+        }[keyof JSX.IntrinsicElements] |
+        ComponentType<P>;
+    type ComponentType<P = {}> = ComponentClass<P> | FunctionComponent<P>;
+
+    type JSXElementConstructor<P> =
+        | ((props: P) => ReactElement<any, any> | null)
+        | (new (props: P) => Component<any, any>);
+
+    interface RefObject<T> {
+        readonly current: T | null;
+    }
+    // Bivariance hack for consistent unsoundness with RefObject
+    type RefCallback<T> = { bivarianceHack(instance: T | null): void }["bivarianceHack"];
+    type Ref<T> = RefCallback<T> | RefObject<T> | null;
+    type LegacyRef<T> = string | Ref<T>;
+    /**
+     * Gets the instance type for a React element. The instance will be different for various component types:
+     *
+     * - React class components will be the class instance. So if you had `class Foo extends React.Component<{}> {}`
+     *   and used `React.ElementRef<typeof Foo>` then the type would be the instance of `Foo`.
+     * - React stateless functional components do not have a backing instance and so `React.ElementRef<typeof Bar>`
+     *   (when `Bar` is `function Bar() {}`) will give you the `undefined` type.
+     * - JSX intrinsics like `div` will give you their DOM instance. For `React.ElementRef<'div'>` that would be
+     *   `HTMLDivElement`. For `React.ElementRef<'input'>` that would be `HTMLInputElement`.
+     * - React stateless functional components that forward a `ref` will give you the `ElementRef` of the forwarded
+     *   to component.
+     *
+     * `C` must be the type _of_ a React component so you need to use typeof as in React.ElementRef<typeof MyComponent>.
+     *
+     * @todo In Flow, this works a little different with forwarded refs and the `AbstractComponent` that
+     *       `React.forwardRef()` returns.
+     */
+    type ElementRef<
+        C extends
+            | ForwardRefExoticComponent<any>
+            | { new (props: any): Component<any> }
+            | ((props: any, context?: any) => ReactElement | null)
+            | keyof JSX.IntrinsicElements
+    > =
+        // need to check first if `ref` is a valid prop for ts@3.0
+        // otherwise it will infer `{}` instead of `never`
+        "ref" extends keyof ComponentPropsWithRef<C>
+            ? NonNullable<ComponentPropsWithRef<C>["ref"]> extends Ref<
+                infer Instance
+            >
+                ? Instance
+                : never
+            : never;
+
+    type ComponentState = any;
+
+    type Key = string | number;
+
+    /**
+     * @internal You shouldn't need to use this type since you never see these attributes
+     * inside your component or have to validate them.
+     */
+    interface Attributes {
+        key?: Key | null | undefined;
+    }
+    interface RefAttributes<T> extends Attributes {
+        ref?: Ref<T> | undefined;
+    }
+    interface ClassAttributes<T> extends Attributes {
+        ref?: LegacyRef<T> | undefined;
+    }
+
+    interface ReactElement<P = any, T extends string | JSXElementConstructor<any> = string | JSXElementConstructor<any>> {
+        type: T;
+        props: P;
+        key: Key | null;
+    }
+
+    interface ReactComponentElement<
+        T extends keyof JSX.IntrinsicElements | JSXElementConstructor<any>,
+        P = Pick<ComponentProps<T>, Exclude<keyof ComponentProps<T>, 'key' | 'ref'>>
+    > extends ReactElement<P, Exclude<T, number>> { }
+
+    interface FunctionComponentElement<P> extends ReactElement<P, FunctionComponent<P>> {
+        ref?: ('ref' extends keyof P ? P extends { ref?: infer R | undefined } ? R : never : never) | undefined;
+    }
+
+    type CElement<P, T extends Component<P, ComponentState>> = ComponentElement<P, T>;
+    interface ComponentElement<P, T extends Component<P, ComponentState>> extends ReactElement<P, ComponentClass<P>> {
+        ref?: LegacyRef<T> | undefined;
+    }
+
+    type ClassicElement<P> = CElement<P, ClassicComponent<P, ComponentState>>;
+
+    // string fallback for custom web-components
+    interface DOMElement<P extends HTMLAttributes<T> | SVGAttributes<T>, T extends Element> extends ReactElement<P, string> {
+        ref: LegacyRef<T>;
+    }
+
+    // ReactHTML for ReactHTMLElement
+    interface ReactHTMLElement<T extends HTMLElement> extends DetailedReactHTMLElement<AllHTMLAttributes<T>, T> { }
+
+    interface DetailedReactHTMLElement<P extends HTMLAttributes<T>, T extends HTMLElement> extends DOMElement<P, T> {
+        type: keyof ReactHTML;
+    }
+
+    // ReactSVG for ReactSVGElement
+    interface ReactSVGElement extends DOMElement<SVGAttributes<SVGElement>, SVGElement> {
+        type: keyof ReactSVG;
+    }
+
+    interface ReactPortal extends ReactElement {
+        key: Key | null;
+        children: ReactNode;
+    }
+
+    //
+    // Factories
+    // ----------------------------------------------------------------------
+
+    type Factory<P> = (props?: Attributes & P, ...children: ReactNode[]) => ReactElement<P>;
+
+    /**
+     * @deprecated Please use `FunctionComponentFactory`
+     */
+    type SFCFactory<P> = FunctionComponentFactory<P>;
+
+    type FunctionComponentFactory<P> = (props?: Attributes & P, ...children: ReactNode[]) => FunctionComponentElement<P>;
+
+    type ComponentFactory<P, T extends Component<P, ComponentState>> =
+        (props?: ClassAttributes<T> & P, ...children: ReactNode[]) => CElement<P, T>;
+
+    type CFactory<P, T extends Component<P, ComponentState>> = ComponentFactory<P, T>;
+    type ClassicFactory<P> = CFactory<P, ClassicComponent<P, ComponentState>>;
+
+    type DOMFactory<P extends DOMAttributes<T>, T extends Element> =
+        (props?: ClassAttributes<T> & P | null, ...children: ReactNode[]) => DOMElement<P, T>;
+
+    interface HTMLFactory<T extends HTMLElement> extends DetailedHTMLFactory<AllHTMLAttributes<T>, T> {}
+
+    interface DetailedHTMLFactory<P extends HTMLAttributes<T>, T extends HTMLElement> extends DOMFactory<P, T> {
+        (props?: ClassAttributes<T> & P | null, ...children: ReactNode[]): DetailedReactHTMLElement<P, T>;
+    }
+
+    interface SVGFactory extends DOMFactory<SVGAttributes<SVGElement>, SVGElement> {
+        (props?: ClassAttributes<SVGElement> & SVGAttributes<SVGElement> | null, ...children: ReactNode[]): ReactSVGElement;
+    }
+
+    //
+    // React Nodes
+    // http://facebook.github.io/react/docs/glossary.html
+    // ----------------------------------------------------------------------
+
+    type ReactText = string | number;
+    type ReactChild = ReactElement | ReactText;
+
+    /**
+     * @deprecated Use either `ReactNode[]` if you need an array or `Iterable<ReactNode>` if its passed to a host component.
+     */
+    interface ReactNodeArray extends ReadonlyArray<ReactNode> {}
+    type ReactFragment = Iterable<ReactNode>;
+    type ReactNode = ReactChild | ReactFragment | ReactPortal | boolean | null | undefined;
+
+    //
+    // Top Level API
+    // ----------------------------------------------------------------------
+
+    // DOM Elements
+    function createFactory<T extends HTMLElement>(
+        type: keyof ReactHTML): HTMLFactory<T>;
+    function createFactory(
+        type: keyof ReactSVG): SVGFactory;
+    function createFactory<P extends DOMAttributes<T>, T extends Element>(
+        type: string): DOMFactory<P, T>;
+
+    // Custom components
+    function createFactory<P>(type: FunctionComponent<P>): FunctionComponentFactory<P>;
+    function createFactory<P>(
+        type: ClassType<P, ClassicComponent<P, ComponentState>, ClassicComponentClass<P>>): CFactory<P, ClassicComponent<P, ComponentState>>;
+    function createFactory<P, T extends Component<P, ComponentState>, C extends ComponentClass<P>>(
+        type: ClassType<P, T, C>): CFactory<P, T>;
+    function createFactory<P>(type: ComponentClass<P>): Factory<P>;
+
+    // DOM Elements
+    // TODO: generalize this to everything in `keyof ReactHTML`, not just "input"
+    function createElement(
+        type: "input",
+        props?: InputHTMLAttributes<HTMLInputElement> & ClassAttributes<HTMLInputElement> | null,
+        ...children: ReactNode[]): DetailedReactHTMLElement<InputHTMLAttributes<HTMLInputElement>, HTMLInputElement>;
+    function createElement<P extends HTMLAttributes<T>, T extends HTMLElement>(
+        type: keyof ReactHTML,
+        props?: ClassAttributes<T> & P | null,
+        ...children: ReactNode[]): DetailedReactHTMLElement<P, T>;
+    function createElement<P extends SVGAttributes<T>, T extends SVGElement>(
+        type: keyof ReactSVG,
+        props?: ClassAttributes<T> & P | null,
+        ...children: ReactNode[]): ReactSVGElement;
+    function createElement<P extends DOMAttributes<T>, T extends Element>(
+        type: string,
+        props?: ClassAttributes<T> & P | null,
+        ...children: ReactNode[]): DOMElement<P, T>;
+
+    // Custom components
+
+    function createElement<P extends {}>(
+        type: FunctionComponent<P>,
+        props?: Attributes & P | null,
+        ...children: ReactNode[]): FunctionComponentElement<P>;
+    function createElement<P extends {}>(
+        type: ClassType<P, ClassicComponent<P, ComponentState>, ClassicComponentClass<P>>,
+        props?: ClassAttributes<ClassicComponent<P, ComponentState>> & P | null,
+        ...children: ReactNode[]): CElement<P, ClassicComponent<P, ComponentState>>;
+    function createElement<P extends {}, T extends Component<P, ComponentState>, C extends ComponentClass<P>>(
+        type: ClassType<P, T, C>,
+        props?: ClassAttributes<T> & P | null,
+        ...children: ReactNode[]): CElement<P, T>;
+    function createElement<P extends {}>(
+        type: FunctionComponent<P> | ComponentClass<P> | string,
+        props?: Attributes & P | null,
+        ...children: ReactNode[]): ReactElement<P>;
+
+    // DOM Elements
+    // ReactHTMLElement
+    function cloneElement<P extends HTMLAttributes<T>, T extends HTMLElement>(
+        element: DetailedReactHTMLElement<P, T>,
+        props?: P,
+        ...children: ReactNode[]): DetailedReactHTMLElement<P, T>;
+    // ReactHTMLElement, less specific
+    function cloneElement<P extends HTMLAttributes<T>, T extends HTMLElement>(
+        element: ReactHTMLElement<T>,
+        props?: P,
+        ...children: ReactNode[]): ReactHTMLElement<T>;
+    // SVGElement
+    function cloneElement<P extends SVGAttributes<T>, T extends SVGElement>(
+        element: ReactSVGElement,
+        props?: P,
+        ...children: ReactNode[]): ReactSVGElement;
+    // DOM Element (has to be the last, because type checking stops at first overload that fits)
+    function cloneElement<P extends DOMAttributes<T>, T extends Element>(
+        element: DOMElement<P, T>,
+        props?: DOMAttributes<T> & P,
+        ...children: ReactNode[]): DOMElement<P, T>;
+
+    // Custom components
+    function cloneElement<P>(
+        element: FunctionComponentElement<P>,
+        props?: Partial<P> & Attributes,
+        ...children: ReactNode[]): FunctionComponentElement<P>;
+    function cloneElement<P, T extends Component<P, ComponentState>>(
+        element: CElement<P, T>,
+        props?: Partial<P> & ClassAttributes<T>,
+        ...children: ReactNode[]): CElement<P, T>;
+    function cloneElement<P>(
+        element: ReactElement<P>,
+        props?: Partial<P> & Attributes,
+        ...children: ReactNode[]): ReactElement<P>;
+
+    // Context via RenderProps
+    interface ProviderProps<T> {
+        value: T;
+        children?: ReactNode | undefined;
+    }
+
+    interface ConsumerProps<T> {
+        children: (value: T) => ReactNode;
+    }
+
+    // TODO: similar to how Fragment is actually a symbol, the values returned from createContext,
+    // forwardRef and memo are actually objects that are treated specially by the renderer; see:
+    // https://github.com/facebook/react/blob/v16.6.0/packages/react/src/ReactContext.js#L35-L48
+    // https://github.com/facebook/react/blob/v16.6.0/packages/react/src/forwardRef.js#L42-L45
+    // https://github.com/facebook/react/blob/v16.6.0/packages/react/src/memo.js#L27-L31
+    // However, we have no way of telling the JSX parser that it's a JSX element type or its props other than
+    // by pretending to be a normal component.
+    //
+    // We don't just use ComponentType or FunctionComponent types because you are not supposed to attach statics to this
+    // object, but rather to the original function.
+    interface ExoticComponent<P = {}> {
+        /**
+         * **NOTE**: Exotic components are not callable.
+         */
+        (props: P): (ReactElement|null);
+        readonly $$typeof: symbol;
+    }
+
+    interface NamedExoticComponent<P = {}> extends ExoticComponent<P> {
+        displayName?: string | undefined;
+    }
+
+    interface ProviderExoticComponent<P> extends ExoticComponent<P> {
+        propTypes?: WeakValidationMap<P> | undefined;
+    }
+
+    type ContextType<C extends Context<any>> = C extends Context<infer T> ? T : never;
+
+    // NOTE: only the Context object itself can get a displayName
+    // https://github.com/facebook/react-devtools/blob/e0b854e4c/backend/attachRendererFiber.js#L310-L325
+    type Provider<T> = ProviderExoticComponent<ProviderProps<T>>;
+    type Consumer<T> = ExoticComponent<ConsumerProps<T>>;
+    interface Context<T> {
+        Provider: Provider<T>;
+        Consumer: Consumer<T>;
+        displayName?: string | undefined;
+    }
+    function createContext<T>(
+        // If you thought this should be optional, see
+        // https://github.com/DefinitelyTyped/DefinitelyTyped/pull/24509#issuecomment-382213106
+        defaultValue: T,
+    ): Context<T>;
+
+    function isValidElement<P>(object: {} | null | undefined): object is ReactElement<P>;
+
+    const Children: ReactChildren;
+    const Fragment: ExoticComponent<{ children?: ReactNode | undefined }>;
+    const StrictMode: ExoticComponent<{ children?: ReactNode | undefined }>;
+
+    interface SuspenseProps {
+        children?: ReactNode | undefined;
+
+        // TODO(react18): `fallback?: ReactNode;`
+        /** A fallback react tree to show when a Suspense child (like React.lazy) suspends */
+        fallback: NonNullable<ReactNode>|null;
+    }
+
+    // TODO(react18): Updated JSDoc to reflect that Suspense works on the server.
+    /**
+     * This feature is not yet available for server-side rendering.
+     * Suspense support will be added in a later release.
+     */
+    const Suspense: ExoticComponent<SuspenseProps>;
+    const version: string;
+
+    /**
+     * {@link https://reactjs.org/docs/profiler.html#onrender-callback Profiler API}
+     */
+    type ProfilerOnRenderCallback = (
+        id: string,
+        phase: "mount" | "update",
+        actualDuration: number,
+        baseDuration: number,
+        startTime: number,
+        commitTime: number,
+        interactions: Set<SchedulerInteraction>,
+    ) => void;
+    interface ProfilerProps {
+        children?: ReactNode | undefined;
+        id: string;
+        onRender: ProfilerOnRenderCallback;
+    }
+
+    const Profiler: ExoticComponent<ProfilerProps>;
+
+    //
+    // Component API
+    // ----------------------------------------------------------------------
+
+    type ReactInstance = Component<any> | Element;
+
+    // Base component for plain JS classes
+    interface Component<P = {}, S = {}, SS = any> extends ComponentLifecycle<P, S, SS> { }
+    class Component<P, S> {
+        // tslint won't let me format the sample code in a way that vscode likes it :(
+        /**
+         * If set, `this.context` will be set at runtime to the current value of the given Context.
+         *
+         * Usage:
+         *
+         * ```ts
+         * type MyContext = number
+         * const Ctx = React.createContext<MyContext>(0)
+         *
+         * class Foo extends React.Component {
+         *   static contextType = Ctx
+         *   context!: React.ContextType<typeof Ctx>
+         *   render () {
+         *     return <>My context's value: {this.context}</>;
+         *   }
+         * }
+         * ```
+         *
+         * @see https://reactjs.org/docs/context.html#classcontexttype
+         */
+        static contextType?: Context<any> | undefined;
+
+        /**
+         * If using the new style context, re-declare this in your class to be the
+         * `React.ContextType` of your `static contextType`.
+         * Should be used with type annotation or static contextType.
+         *
+         * ```ts
+         * static contextType = MyContext
+         * // For TS pre-3.7:
+         * context!: React.ContextType<typeof MyContext>
+         * // For TS 3.7 and above:
+         * declare context: React.ContextType<typeof MyContext>
+         * ```
+         *
+         * @see https://reactjs.org/docs/context.html
+         */
+        context: unknown;
+
+        constructor(props: Readonly<P> | P);
+        /**
+         * @deprecated
+         * @see https://reactjs.org/docs/legacy-context.html
+         */
+        constructor(props: P, context: any);
+
+        // We MUST keep setState() as a unified signature because it allows proper checking of the method return type.
+        // See: https://github.com/DefinitelyTyped/DefinitelyTyped/issues/18365#issuecomment-351013257
+        // Also, the ` | S` allows intellisense to not be dumbisense
+        setState<K extends keyof S>(
+            state: ((prevState: Readonly<S>, props: Readonly<P>) => (Pick<S, K> | S | null)) | (Pick<S, K> | S | null),
+            callback?: () => void
+        ): void;
+
+        forceUpdate(callback?: () => void): void;
+        render(): ReactNode;
+
+        readonly props: Readonly<P>;
+        state: Readonly<S>;
+        /**
+         * @deprecated
+         * https://reactjs.org/docs/refs-and-the-dom.html#legacy-api-string-refs
+         */
+        refs: {
+            [key: string]: ReactInstance
+        };
+    }
+
+    class PureComponent<P = {}, S = {}, SS = any> extends Component<P, S, SS> { }
+
+    interface ClassicComponent<P = {}, S = {}> extends Component<P, S> {
+        replaceState(nextState: S, callback?: () => void): void;
+        isMounted(): boolean;
+        getInitialState?(): S;
+    }
+
+    interface ChildContextProvider<CC> {
+        getChildContext(): CC;
+    }
+
+    //
+    // Class Interfaces
+    // ----------------------------------------------------------------------
+
+    type FC<P = {}> = FunctionComponent<P>;
+
+    interface FunctionComponent<P = {}> {
+        (props: P, context?: any): ReactElement<any, any> | null;
+        propTypes?: WeakValidationMap<P> | undefined;
+        contextTypes?: ValidationMap<any> | undefined;
+        defaultProps?: Partial<P> | undefined;
+        displayName?: string | undefined;
+    }
+
+    type VFC<P = {}> = VoidFunctionComponent<P>;
+
+    interface VoidFunctionComponent<P = {}> {
+        (props: P, context?: any): ReactElement<any, any> | null;
+        propTypes?: WeakValidationMap<P> | undefined;
+        contextTypes?: ValidationMap<any> | undefined;
+        defaultProps?: Partial<P> | undefined;
+        displayName?: string | undefined;
+    }
+
+    type ForwardedRef<T> = ((instance: T | null) => void) | MutableRefObject<T | null> | null;
+
+    interface ForwardRefRenderFunction<T, P = {}> {
+        (props: P, ref: ForwardedRef<T>): ReactElement | null;
+        displayName?: string | undefined;
+        // explicit rejected with `never` required due to
+        // https://github.com/microsoft/TypeScript/issues/36826
+        /**
+         * defaultProps are not supported on render functions
+         */
+        defaultProps?: never | undefined;
+        /**
+         * propTypes are not supported on render functions
+         */
+        propTypes?: never | undefined;
+    }
+
+    interface ComponentClass<P = {}, S = ComponentState> extends StaticLifecycle<P, S> {
+        new (props: P, context?: any): Component<P, S>;
+        propTypes?: WeakValidationMap<P> | undefined;
+        contextType?: Context<any> | undefined;
+        contextTypes?: ValidationMap<any> | undefined;
+        childContextTypes?: ValidationMap<any> | undefined;
+        defaultProps?: Partial<P> | undefined;
+        displayName?: string | undefined;
+    }
+
+    interface ClassicComponentClass<P = {}> extends ComponentClass<P> {
+        new (props: P, context?: any): ClassicComponent<P, ComponentState>;
+        getDefaultProps?(): P;
+    }
+
+    /**
+     * We use an intersection type to infer multiple type parameters from
+     * a single argument, which is useful for many top-level API defs.
+     * See https://github.com/Microsoft/TypeScript/issues/7234 for more info.
+     */
+    type ClassType<P, T extends Component<P, ComponentState>, C extends ComponentClass<P>> =
+        C &
+        (new (props: P, context?: any) => T);
+
+    //
+    // Component Specs and Lifecycle
+    // ----------------------------------------------------------------------
+
+    // This should actually be something like `Lifecycle<P, S> | DeprecatedLifecycle<P, S>`,
+    // as React will _not_ call the deprecated lifecycle methods if any of the new lifecycle
+    // methods are present.
+    interface ComponentLifecycle<P, S, SS = any> extends NewLifecycle<P, S, SS>, DeprecatedLifecycle<P, S> {
+        /**
+         * Called immediately after a component is mounted. Setting state here will trigger re-rendering.
+         */
+        componentDidMount?(): void;
+        /**
+         * Called to determine whether the change in props and state should trigger a re-render.
+         *
+         * `Component` always returns true.
+         * `PureComponent` implements a shallow comparison on props and state and returns true if any
+         * props or states have changed.
+         *
+         * If false is returned, `Component#render`, `componentWillUpdate`
+         * and `componentDidUpdate` will not be called.
+         */
+        shouldComponentUpdate?(nextProps: Readonly<P>, nextState: Readonly<S>, nextContext: any): boolean;
+        /**
+         * Called immediately before a component is destroyed. Perform any necessary cleanup in this method, such as
+         * cancelled network requests, or cleaning up any DOM elements created in `componentDidMount`.
+         */
+        componentWillUnmount?(): void;
+        /**
+         * Catches exceptions generated in descendant components. Unhandled exceptions will cause
+         * the entire component tree to unmount.
+         */
+        componentDidCatch?(error: Error, errorInfo: ErrorInfo): void;
+    }
+
+    // Unfortunately, we have no way of declaring that the component constructor must implement this
+    interface StaticLifecycle<P, S> {
+        getDerivedStateFromProps?: GetDerivedStateFromProps<P, S> | undefined;
+        getDerivedStateFromError?: GetDerivedStateFromError<P, S> | undefined;
+    }
+
+    type GetDerivedStateFromProps<P, S> =
+        /**
+         * Returns an update to a component's state based on its new props and old state.
+         *
+         * Note: its presence prevents any of the deprecated lifecycle methods from being invoked
+         */
+        (nextProps: Readonly<P>, prevState: S) => Partial<S> | null;
+
+    type GetDerivedStateFromError<P, S> =
+        /**
+         * This lifecycle is invoked after an error has been thrown by a descendant component.
+         * It receives the error that was thrown as a parameter and should return a value to update state.
+         *
+         * Note: its presence prevents any of the deprecated lifecycle methods from being invoked
+         */
+        (error: any) => Partial<S> | null;
+
+    // This should be "infer SS" but can't use it yet
+    interface NewLifecycle<P, S, SS> {
+        /**
+         * Runs before React applies the result of `render` to the document, and
+         * returns an object to be given to componentDidUpdate. Useful for saving
+         * things such as scroll position before `render` causes changes to it.
+         *
+         * Note: the presence of getSnapshotBeforeUpdate prevents any of the deprecated
+         * lifecycle events from running.
+         */
+        getSnapshotBeforeUpdate?(prevProps: Readonly<P>, prevState: Readonly<S>): SS | null;
+        /**
+         * Called immediately after updating occurs. Not called for the initial render.
+         *
+         * The snapshot is only present if getSnapshotBeforeUpdate is present and returns non-null.
+         */
+        componentDidUpdate?(prevProps: Readonly<P>, prevState: Readonly<S>, snapshot?: SS): void;
+    }
+
+    interface DeprecatedLifecycle<P, S> {
+        /**
+         * Called immediately before mounting occurs, and before `Component#render`.
+         * Avoid introducing any side-effects or subscriptions in this method.
+         *
+         * Note: the presence of getSnapshotBeforeUpdate or getDerivedStateFromProps
+         * prevents this from being invoked.
+         *
+         * @deprecated 16.3, use componentDidMount or the constructor instead; will stop working in React 17
+         * @see https://reactjs.org/blog/2018/03/27/update-on-async-rendering.html#initializing-state
+         * @see https://reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path
+         */
+        componentWillMount?(): void;
+        /**
+         * Called immediately before mounting occurs, and before `Component#render`.
+         * Avoid introducing any side-effects or subscriptions in this method.
+         *
+         * This method will not stop working in React 17.
+         *
+         * Note: the presence of getSnapshotBeforeUpdate or getDerivedStateFromProps
+         * prevents this from being invoked.
+         *
+         * @deprecated 16.3, use componentDidMount or the constructor instead
+         * @see https://reactjs.org/blog/2018/03/27/update-on-async-rendering.html#initializing-state
+         * @see https://reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path
+         */
+        UNSAFE_componentWillMount?(): void;
+        /**
+         * Called when the component may be receiving new props.
+         * React may call this even if props have not changed, so be sure to compare new and existing
+         * props if you only want to handle changes.
+         *
+         * Calling `Component#setState` generally does not trigger this method.
+         *
+         * Note: the presence of getSnapshotBeforeUpdate or getDerivedStateFromProps
+         * prevents this from being invoked.
+         *
+         * @deprecated 16.3, use static getDerivedStateFromProps instead; will stop working in React 17
+         * @see https://reactjs.org/blog/2018/03/27/update-on-async-rendering.html#updating-state-based-on-props
+         * @see https://reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path
+         */
+        componentWillReceiveProps?(nextProps: Readonly<P>, nextContext: any): void;
+        /**
+         * Called when the component may be receiving new props.
+         * React may call this even if props have not changed, so be sure to compare new and existing
+         * props if you only want to handle changes.
+         *
+         * Calling `Component#setState` generally does not trigger this method.
+         *
+         * This method will not stop working in React 17.
+         *
+         * Note: the presence of getSnapshotBeforeUpdate or getDerivedStateFromProps
+         * prevents this from being invoked.
+         *
+         * @deprecated 16.3, use static getDerivedStateFromProps instead
+         * @see https://reactjs.org/blog/2018/03/27/update-on-async-rendering.html#updating-state-based-on-props
+         * @see https://reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path
+         */
+        UNSAFE_componentWillReceiveProps?(nextProps: Readonly<P>, nextContext: any): void;
+        /**
+         * Called immediately before rendering when new props or state is received. Not called for the initial render.
+         *
+         * Note: You cannot call `Component#setState` here.
+         *
+         * Note: the presence of getSnapshotBeforeUpdate or getDerivedStateFromProps
+         * prevents this from being invoked.
+         *
+         * @deprecated 16.3, use getSnapshotBeforeUpdate instead; will stop working in React 17
+         * @see https://reactjs.org/blog/2018/03/27/update-on-async-rendering.html#reading-dom-properties-before-an-update
+         * @see https://reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path
+         */
+        componentWillUpdate?(nextProps: Readonly<P>, nextState: Readonly<S>, nextContext: any): void;
+        /**
+         * Called immediately before rendering when new props or state is received. Not called for the initial render.
+         *
+         * Note: You cannot call `Component#setState` here.
+         *
+         * This method will not stop working in React 17.
+         *
+         * Note: the presence of getSnapshotBeforeUpdate or getDerivedStateFromProps
+         * prevents this from being invoked.
+         *
+         * @deprecated 16.3, use getSnapshotBeforeUpdate instead
+         * @see https://reactjs.org/blog/2018/03/27/update-on-async-rendering.html#reading-dom-properties-before-an-update
+         * @see https://reactjs.org/blog/2018/03/27/update-on-async-rendering.html#gradual-migration-path
+         */
+        UNSAFE_componentWillUpdate?(nextProps: Readonly<P>, nextState: Readonly<S>, nextContext: any): void;
+    }
+
+    interface Mixin<P, S> extends ComponentLifecycle<P, S> {
+        mixins?: Array<Mixin<P, S>> | undefined;
+        statics?: {
+            [key: string]: any;
+        } | undefined;
+
+        displayName?: string | undefined;
+        propTypes?: ValidationMap<any> | undefined;
+        contextTypes?: ValidationMap<any> | undefined;
+        childContextTypes?: ValidationMap<any> | undefined;
+
+        getDefaultProps?(): P;
+        getInitialState?(): S;
+    }
+
+    interface ComponentSpec<P, S> extends Mixin<P, S> {
+        render(): ReactNode;
+
+        [propertyName: string]: any;
+    }
+
+    function createRef<T>(): RefObject<T>;
+
+    // will show `ForwardRef(${Component.displayName || Component.name})` in devtools by default,
+    // but can be given its own specific name
+    interface ForwardRefExoticComponent<P> extends NamedExoticComponent<P> {
+        defaultProps?: Partial<P> | undefined;
+        propTypes?: WeakValidationMap<P> | undefined;
+    }
+
+    function forwardRef<T, P = {}>(render: ForwardRefRenderFunction<T, P>): ForwardRefExoticComponent<PropsWithoutRef<P> & RefAttributes<T>>;
+
+    /** Ensures that the props do not include ref at all */
+    type PropsWithoutRef<P> =
+        // Pick would not be sufficient for this. We'd like to avoid unnecessary mapping and need a distributive conditional to support unions.
+        // see: https://www.typescriptlang.org/docs/handbook/2/conditional-types.html#distributive-conditional-types
+        // https://github.com/Microsoft/TypeScript/issues/28339
+        P extends any ? ('ref' extends keyof P ? Pick<P, Exclude<keyof P, 'ref'>> : P) : P;
+    /** Ensures that the props do not include string ref, which cannot be forwarded */
+    type PropsWithRef<P> =
+        // Just "P extends { ref?: infer R }" looks sufficient, but R will infer as {} if P is {}.
+        'ref' extends keyof P
+            ? P extends { ref?: infer R | undefined }
+                ? string extends R
+                    ? PropsWithoutRef<P> & { ref?: Exclude<R, string> | undefined }
+                    : P
+                : P
+            : P;
+
+    type PropsWithChildren<P> = P & { children?: ReactNode | undefined };
+
+    /**
+     * NOTE: prefer ComponentPropsWithRef, if the ref is forwarded,
+     * or ComponentPropsWithoutRef when refs are not supported.
+     */
+    type ComponentProps<T extends keyof JSX.IntrinsicElements | JSXElementConstructor<any>> =
+        T extends JSXElementConstructor<infer P>
+            ? P
+            : T extends keyof JSX.IntrinsicElements
+                ? JSX.IntrinsicElements[T]
+                : {};
+    type ComponentPropsWithRef<T extends ElementType> =
+        T extends (new (props: infer P) => Component<any, any>)
+            ? PropsWithoutRef<P> & RefAttributes<InstanceType<T>>
+            : PropsWithRef<ComponentProps<T>>;
+    type ComponentPropsWithoutRef<T extends ElementType> =
+        PropsWithoutRef<ComponentProps<T>>;
+
+    type ComponentRef<T extends ElementType> = T extends NamedExoticComponent<
+        ComponentPropsWithoutRef<T> & RefAttributes<infer Method>
+    >
+        ? Method
+        : ComponentPropsWithRef<T> extends RefAttributes<infer Method>
+            ? Method
+            : never;
+
+    // will show `Memo(${Component.displayName || Component.name})` in devtools by default,
+    // but can be given its own specific name
+    type MemoExoticComponent<T extends ComponentType<any>> = NamedExoticComponent<ComponentPropsWithRef<T>> & {
+        readonly type: T;
+    };
+
+    function memo<P extends object>(
+        Component: FunctionComponent<P>,
+        propsAreEqual?: (prevProps: Readonly<P>, nextProps: Readonly<P>) => boolean
+    ): NamedExoticComponent<P>;
+    function memo<T extends ComponentType<any>>(
+        Component: T,
+        propsAreEqual?: (prevProps: Readonly<ComponentProps<T>>, nextProps: Readonly<ComponentProps<T>>) => boolean
+    ): MemoExoticComponent<T>;
+
+    type LazyExoticComponent<T extends ComponentType<any>> = ExoticComponent<ComponentPropsWithRef<T>> & {
+        readonly _result: T;
+    };
+
+    function lazy<T extends ComponentType<any>>(
+        factory: () => Promise<{ default: T }>
+    ): LazyExoticComponent<T>;
+
+    //
+    // React Hooks
+    // ----------------------------------------------------------------------
+
+    // based on the code in https://github.com/facebook/react/pull/13968
+
+    // Unlike the class component setState, the updates are not allowed to be partial
+    type SetStateAction<S> = S | ((prevState: S) => S);
+    // this technically does accept a second argument, but it's already under a deprecation warning
+    // and it's not even released so probably better to not define it.
+    type Dispatch<A> = (value: A) => void;
+    // Since action _can_ be undefined, dispatch may be called without any parameters.
+    type DispatchWithoutAction = () => void;
+    // Unlike redux, the actions _can_ be anything
+    type Reducer<S, A> = (prevState: S, action: A) => S;
+    // If useReducer accepts a reducer without action, dispatch may be called without any parameters.
+    type ReducerWithoutAction<S> = (prevState: S) => S;
+    // types used to try and prevent the compiler from reducing S
+    // to a supertype common with the second argument to useReducer()
+    type ReducerState<R extends Reducer<any, any>> = R extends Reducer<infer S, any> ? S : never;
+    type ReducerAction<R extends Reducer<any, any>> = R extends Reducer<any, infer A> ? A : never;
+    // The identity check is done with the SameValue algorithm (Object.is), which is stricter than ===
+    type ReducerStateWithoutAction<R extends ReducerWithoutAction<any>> =
+        R extends ReducerWithoutAction<infer S> ? S : never;
+    type DependencyList = ReadonlyArray<unknown>;
+
+    // NOTE: callbacks are _only_ allowed to return either void, or a destructor.
+    type EffectCallback = () => (void | Destructor);
+
+    interface MutableRefObject<T> {
+        current: T;
+    }
+
+    // This will technically work if you give a Consumer<T> or Provider<T> but it's deprecated and warns
+    /**
+     * Accepts a context object (the value returned from `React.createContext`) and returns the current
+     * context value, as given by the nearest context provider for the given context.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#usecontext
+     */
+    function useContext<T>(context: Context<T>/*, (not public API) observedBits?: number|boolean */): T;
+    /**
+     * Returns a stateful value, and a function to update it.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#usestate
+     */
+    function useState<S>(initialState: S | (() => S)): [S, Dispatch<SetStateAction<S>>];
+    // convenience overload when first argument is omitted
+    /**
+     * Returns a stateful value, and a function to update it.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#usestate
+     */
+    function useState<S = undefined>(): [S | undefined, Dispatch<SetStateAction<S | undefined>>];
+    /**
+     * An alternative to `useState`.
+     *
+     * `useReducer` is usually preferable to `useState` when you have complex state logic that involves
+     * multiple sub-values. It also lets you optimize performance for components that trigger deep
+     * updates because you can pass `dispatch` down instead of callbacks.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#usereducer
+     */
+    // overload where dispatch could accept 0 arguments.
+    function useReducer<R extends ReducerWithoutAction<any>, I>(
+        reducer: R,
+        initializerArg: I,
+        initializer: (arg: I) => ReducerStateWithoutAction<R>
+    ): [ReducerStateWithoutAction<R>, DispatchWithoutAction];
+    /**
+     * An alternative to `useState`.
+     *
+     * `useReducer` is usually preferable to `useState` when you have complex state logic that involves
+     * multiple sub-values. It also lets you optimize performance for components that trigger deep
+     * updates because you can pass `dispatch` down instead of callbacks.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#usereducer
+     */
+    // overload where dispatch could accept 0 arguments.
+    function useReducer<R extends ReducerWithoutAction<any>>(
+        reducer: R,
+        initializerArg: ReducerStateWithoutAction<R>,
+        initializer?: undefined
+    ): [ReducerStateWithoutAction<R>, DispatchWithoutAction];
+    /**
+     * An alternative to `useState`.
+     *
+     * `useReducer` is usually preferable to `useState` when you have complex state logic that involves
+     * multiple sub-values. It also lets you optimize performance for components that trigger deep
+     * updates because you can pass `dispatch` down instead of callbacks.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#usereducer
+     */
+    // overload where "I" may be a subset of ReducerState<R>; used to provide autocompletion.
+    // If "I" matches ReducerState<R> exactly then the last overload will allow initializer to be omitted.
+    // the last overload effectively behaves as if the identity function (x => x) is the initializer.
+    function useReducer<R extends Reducer<any, any>, I>(
+        reducer: R,
+        initializerArg: I & ReducerState<R>,
+        initializer: (arg: I & ReducerState<R>) => ReducerState<R>
+    ): [ReducerState<R>, Dispatch<ReducerAction<R>>];
+    /**
+     * An alternative to `useState`.
+     *
+     * `useReducer` is usually preferable to `useState` when you have complex state logic that involves
+     * multiple sub-values. It also lets you optimize performance for components that trigger deep
+     * updates because you can pass `dispatch` down instead of callbacks.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#usereducer
+     */
+    // overload for free "I"; all goes as long as initializer converts it into "ReducerState<R>".
+    function useReducer<R extends Reducer<any, any>, I>(
+        reducer: R,
+        initializerArg: I,
+        initializer: (arg: I) => ReducerState<R>
+    ): [ReducerState<R>, Dispatch<ReducerAction<R>>];
+    /**
+     * An alternative to `useState`.
+     *
+     * `useReducer` is usually preferable to `useState` when you have complex state logic that involves
+     * multiple sub-values. It also lets you optimize performance for components that trigger deep
+     * updates because you can pass `dispatch` down instead of callbacks.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#usereducer
+     */
+
+    // I'm not sure if I keep this 2-ary or if I make it (2,3)-ary; it's currently (2,3)-ary.
+    // The Flow types do have an overload for 3-ary invocation with undefined initializer.
+
+    // NOTE: without the ReducerState indirection, TypeScript would reduce S to be the most common
+    // supertype between the reducer's return type and the initialState (or the initializer's return type),
+    // which would prevent autocompletion from ever working.
+
+    // TODO: double-check if this weird overload logic is necessary. It is possible it's either a bug
+    // in older versions, or a regression in newer versions of the typescript completion service.
+    function useReducer<R extends Reducer<any, any>>(
+        reducer: R,
+        initialState: ReducerState<R>,
+        initializer?: undefined
+    ): [ReducerState<R>, Dispatch<ReducerAction<R>>];
+    /**
+     * `useRef` returns a mutable ref object whose `.current` property is initialized to the passed argument
+     * (`initialValue`). The returned object will persist for the full lifetime of the component.
+     *
+     * Note that `useRef()` is useful for more than the `ref` attribute. It’s handy for keeping any mutable
+     * value around similar to how you’d use instance fields in classes.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#useref
+     */
+    function useRef<T>(initialValue: T): MutableRefObject<T>;
+    // convenience overload for refs given as a ref prop as they typically start with a null value
+    /**
+     * `useRef` returns a mutable ref object whose `.current` property is initialized to the passed argument
+     * (`initialValue`). The returned object will persist for the full lifetime of the component.
+     *
+     * Note that `useRef()` is useful for more than the `ref` attribute. It’s handy for keeping any mutable
+     * value around similar to how you’d use instance fields in classes.
+     *
+     * Usage note: if you need the result of useRef to be directly mutable, include `| null` in the type
+     * of the generic argument.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#useref
+     */
+    function useRef<T>(initialValue: T|null): RefObject<T>;
+    // convenience overload for potentially undefined initialValue / call with 0 arguments
+    // has a default to stop it from defaulting to {} instead
+    /**
+     * `useRef` returns a mutable ref object whose `.current` property is initialized to the passed argument
+     * (`initialValue`). The returned object will persist for the full lifetime of the component.
+     *
+     * Note that `useRef()` is useful for more than the `ref` attribute. It’s handy for keeping any mutable
+     * value around similar to how you’d use instance fields in classes.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#useref
+     */
+    function useRef<T = undefined>(): MutableRefObject<T | undefined>;
+    /**
+     * The signature is identical to `useEffect`, but it fires synchronously after all DOM mutations.
+     * Use this to read layout from the DOM and synchronously re-render. Updates scheduled inside
+     * `useLayoutEffect` will be flushed synchronously, before the browser has a chance to paint.
+     *
+     * Prefer the standard `useEffect` when possible to avoid blocking visual updates.
+     *
+     * If you’re migrating code from a class component, `useLayoutEffect` fires in the same phase as
+     * `componentDidMount` and `componentDidUpdate`.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#uselayouteffect
+     */
+    function useLayoutEffect(effect: EffectCallback, deps?: DependencyList): void;
+    /**
+     * Accepts a function that contains imperative, possibly effectful code.
+     *
+     * @param effect Imperative function that can return a cleanup function
+     * @param deps If present, effect will only activate if the values in the list change.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#useeffect
+     */
+    function useEffect(effect: EffectCallback, deps?: DependencyList): void;
+    // NOTE: this does not accept strings, but this will have to be fixed by removing strings from type Ref<T>
+    /**
+     * `useImperativeHandle` customizes the instance value that is exposed to parent components when using
+     * `ref`. As always, imperative code using refs should be avoided in most cases.
+     *
+     * `useImperativeHandle` should be used with `React.forwardRef`.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#useimperativehandle
+     */
+    function useImperativeHandle<T, R extends T>(ref: Ref<T>|undefined, init: () => R, deps?: DependencyList): void;
+    // I made 'inputs' required here and in useMemo as there's no point to memoizing without the memoization key
+    // useCallback(X) is identical to just using X, useMemo(() => Y) is identical to just using Y.
+    /**
+     * `useCallback` will return a memoized version of the callback that only changes if one of the `inputs`
+     * has changed.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#usecallback
+     */
+    // A specific function type would not trigger implicit any.
+    // See https://github.com/DefinitelyTyped/DefinitelyTyped/issues/52873#issuecomment-845806435 for a comparison between `Function` and more specific types.
+    // tslint:disable-next-line ban-types
+    function useCallback<T extends Function>(callback: T, deps: DependencyList): T;
+    /**
+     * `useMemo` will only recompute the memoized value when one of the `deps` has changed.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#usememo
+     */
+    // allow undefined, but don't make it optional as that is very likely a mistake
+    function useMemo<T>(factory: () => T, deps: DependencyList | undefined): T;
+    /**
+     * `useDebugValue` can be used to display a label for custom hooks in React DevTools.
+     *
+     * NOTE: We don’t recommend adding debug values to every custom hook.
+     * It’s most valuable for custom hooks that are part of shared libraries.
+     *
+     * @version 16.8.0
+     * @see https://reactjs.org/docs/hooks-reference.html#usedebugvalue
+     */
+    // the name of the custom hook is itself derived from the function name at runtime:
+    // it's just the function name without the "use" prefix.
+    function useDebugValue<T>(value: T, format?: (value: T) => any): void;
+
+    //
+    // Event System
+    // ----------------------------------------------------------------------
+    // TODO: change any to unknown when moving to TS v3
+    interface BaseSyntheticEvent<E = object, C = any, T = any> {
+        nativeEvent: E;
+        currentTarget: C;
+        target: T;
+        bubbles: boolean;
+        cancelable: boolean;
+        defaultPrevented: boolean;
+        eventPhase: number;
+        isTrusted: boolean;
+        preventDefault(): void;
+        isDefaultPrevented(): boolean;
+        stopPropagation(): void;
+        isPropagationStopped(): boolean;
+        persist(): void;
+        timeStamp: number;
+        type: string;
+    }
+
+    /**
+     * currentTarget - a reference to the element on which the event listener is registered.
+     *
+     * target - a reference to the element from which the event was originally dispatched.
+     * This might be a child element to the element on which the event listener is registered.
+     * If you thought this should be `EventTarget & T`, see https://github.com/DefinitelyTyped/DefinitelyTyped/issues/11508#issuecomment-256045682
+     */
+    interface SyntheticEvent<T = Element, E = Event> extends BaseSyntheticEvent<E, EventTarget & T, EventTarget> {}
+
+    interface ClipboardEvent<T = Element> extends SyntheticEvent<T, NativeClipboardEvent> {
+        clipboardData: DataTransfer;
+    }
+
+    interface CompositionEvent<T = Element> extends SyntheticEvent<T, NativeCompositionEvent> {
+        data: string;
+    }
+
+    interface DragEvent<T = Element> extends MouseEvent<T, NativeDragEvent> {
+        dataTransfer: DataTransfer;
+    }
+
+    interface PointerEvent<T = Element> extends MouseEvent<T, NativePointerEvent> {
+        pointerId: number;
+        pressure: number;
+        tangentialPressure: number;
+        tiltX: number;
+        tiltY: number;
+        twist: number;
+        width: number;
+        height: number;
+        pointerType: 'mouse' | 'pen' | 'touch';
+        isPrimary: boolean;
+    }
+
+    interface FocusEvent<Target = Element, RelatedTarget = Element> extends SyntheticEvent<Target, NativeFocusEvent> {
+        relatedTarget: (EventTarget & RelatedTarget) | null;
+        target: EventTarget & Target;
+    }
+
+    interface FormEvent<T = Element> extends SyntheticEvent<T> {
+    }
+
+    interface InvalidEvent<T = Element> extends SyntheticEvent<T> {
+        target: EventTarget & T;
+    }
+
+    interface ChangeEvent<T = Element> extends SyntheticEvent<T> {
+        target: EventTarget & T;
+    }
+
+    interface KeyboardEvent<T = Element> extends UIEvent<T, NativeKeyboardEvent> {
+        altKey: boolean;
+        /** @deprecated */
+        charCode: number;
+        ctrlKey: boolean;
+        code: string;
+        /**
+         * See [DOM Level 3 Events spec](https://www.w3.org/TR/uievents-key/#keys-modifier). for a list of valid (case-sensitive) arguments to this method.
+         */
+        getModifierState(key: string): boolean;
+        /**
+         * See the [DOM Level 3 Events spec](https://www.w3.org/TR/uievents-key/#named-key-attribute-values). for possible values
+         */
+        key: string;
+        /** @deprecated */
+        keyCode: number;
+        locale: string;
+        location: number;
+        metaKey: boolean;
+        repeat: boolean;
+        shiftKey: boolean;
+        /** @deprecated */
+        which: number;
+    }
+
+    interface MouseEvent<T = Element, E = NativeMouseEvent> extends UIEvent<T, E> {
+        altKey: boolean;
+        button: number;
+        buttons: number;
+        clientX: number;
+        clientY: number;
+        ctrlKey: boolean;
+        /**
+         * See [DOM Level 3 Events spec](https://www.w3.org/TR/uievents-key/#keys-modifier). for a list of valid (case-sensitive) arguments to this method.
+         */
+        getModifierState(key: string): boolean;
+        metaKey: boolean;
+        movementX: number;
+        movementY: number;
+        pageX: number;
+        pageY: number;
+        relatedTarget: EventTarget | null;
+        screenX: number;
+        screenY: number;
+        shiftKey: boolean;
+    }
+
+    interface TouchEvent<T = Element> extends UIEvent<T, NativeTouchEvent> {
+        altKey: boolean;
+        changedTouches: TouchList;
+        ctrlKey: boolean;
+        /**
+         * See [DOM Level 3 Events spec](https://www.w3.org/TR/uievents-key/#keys-modifier). for a list of valid (case-sensitive) arguments to this method.
+         */
+        getModifierState(key: string): boolean;
+        metaKey: boolean;
+        shiftKey: boolean;
+        targetTouches: TouchList;
+        touches: TouchList;
+    }
+
+    interface UIEvent<T = Element, E = NativeUIEvent> extends SyntheticEvent<T, E> {
+        detail: number;
+        view: AbstractView;
+    }
+
+    interface WheelEvent<T = Element> extends MouseEvent<T, NativeWheelEvent> {
+        deltaMode: number;
+        deltaX: number;
+        deltaY: number;
+        deltaZ: number;
+    }
+
+    interface AnimationEvent<T = Element> extends SyntheticEvent<T, NativeAnimationEvent> {
+        animationName: string;
+        elapsedTime: number;
+        pseudoElement: string;
+    }
+
+    interface TransitionEvent<T = Element> extends SyntheticEvent<T, NativeTransitionEvent> {
+        elapsedTime: number;
+        propertyName: string;
+        pseudoElement: string;
+    }
+
+    //
+    // Event Handler Types
+    // ----------------------------------------------------------------------
+
+    type EventHandler<E extends SyntheticEvent<any>> = { bivarianceHack(event: E): void }["bivarianceHack"];
+
+    type ReactEventHandler<T = Element> = EventHandler<SyntheticEvent<T>>;
+
+    type ClipboardEventHandler<T = Element> = EventHandler<ClipboardEvent<T>>;
+    type CompositionEventHandler<T = Element> = EventHandler<CompositionEvent<T>>;
+    type DragEventHandler<T = Element> = EventHandler<DragEvent<T>>;
+    type FocusEventHandler<T = Element> = EventHandler<FocusEvent<T>>;
+    type FormEventHandler<T = Element> = EventHandler<FormEvent<T>>;
+    type ChangeEventHandler<T = Element> = EventHandler<ChangeEvent<T>>;
+    type KeyboardEventHandler<T = Element> = EventHandler<KeyboardEvent<T>>;
+    type MouseEventHandler<T = Element> = EventHandler<MouseEvent<T>>;
+    type TouchEventHandler<T = Element> = EventHandler<TouchEvent<T>>;
+    type PointerEventHandler<T = Element> = EventHandler<PointerEvent<T>>;
+    type UIEventHandler<T = Element> = EventHandler<UIEvent<T>>;
+    type WheelEventHandler<T = Element> = EventHandler<WheelEvent<T>>;
+    type AnimationEventHandler<T = Element> = EventHandler<AnimationEvent<T>>;
+    type TransitionEventHandler<T = Element> = EventHandler<TransitionEvent<T>>;
+
+    //
+    // Props / DOM Attributes
+    // ----------------------------------------------------------------------
+
+    interface HTMLProps<T> extends AllHTMLAttributes<T>, ClassAttributes<T> {
+    }
+
+    type DetailedHTMLProps<E extends HTMLAttributes<T>, T> = ClassAttributes<T> & E;
+
+    interface SVGProps<T> extends SVGAttributes<T>, ClassAttributes<T> {
+    }
+
+    interface DOMAttributes<T> {
+        children?: ReactNode | undefined;
+        dangerouslySetInnerHTML?: {
+            __html: string;
+        } | undefined;
+
+        // Clipboard Events
+        onCopy?: ClipboardEventHandler<T> | undefined;
+        onCopyCapture?: ClipboardEventHandler<T> | undefined;
+        onCut?: ClipboardEventHandler<T> | undefined;
+        onCutCapture?: ClipboardEventHandler<T> | undefined;
+        onPaste?: ClipboardEventHandler<T> | undefined;
+        onPasteCapture?: ClipboardEventHandler<T> | undefined;
+
+        // Composition Events
+        onCompositionEnd?: CompositionEventHandler<T> | undefined;
+        onCompositionEndCapture?: CompositionEventHandler<T> | undefined;
+        onCompositionStart?: CompositionEventHandler<T> | undefined;
+        onCompositionStartCapture?: CompositionEventHandler<T> | undefined;
+        onCompositionUpdate?: CompositionEventHandler<T> | undefined;
+        onCompositionUpdateCapture?: CompositionEventHandler<T> | undefined;
+
+        // Focus Events
+        onFocus?: FocusEventHandler<T> | undefined;
+        onFocusCapture?: FocusEventHandler<T> | undefined;
+        onBlur?: FocusEventHandler<T> | undefined;
+        onBlurCapture?: FocusEventHandler<T> | undefined;
+
+        // Form Events
+        onChange?: FormEventHandler<T> | undefined;
+        onChangeCapture?: FormEventHandler<T> | undefined;
+        onBeforeInput?: FormEventHandler<T> | undefined;
+        onBeforeInputCapture?: FormEventHandler<T> | undefined;
+        onInput?: FormEventHandler<T> | undefined;
+        onInputCapture?: FormEventHandler<T> | undefined;
+        onReset?: FormEventHandler<T> | undefined;
+        onResetCapture?: FormEventHandler<T> | undefined;
+        onSubmit?: FormEventHandler<T> | undefined;
+        onSubmitCapture?: FormEventHandler<T> | undefined;
+        onInvalid?: FormEventHandler<T> | undefined;
+        onInvalidCapture?: FormEventHandler<T> | undefined;
+
+        // Image Events
+        onLoad?: ReactEventHandler<T> | undefined;
+        onLoadCapture?: ReactEventHandler<T> | undefined;
+        onError?: ReactEventHandler<T> | undefined; // also a Media Event
+        onErrorCapture?: ReactEventHandler<T> | undefined; // also a Media Event
+
+        // Keyboard Events
+        onKeyDown?: KeyboardEventHandler<T> | undefined;
+        onKeyDownCapture?: KeyboardEventHandler<T> | undefined;
+        /** @deprecated */
+        onKeyPress?: KeyboardEventHandler<T> | undefined;
+        /** @deprecated */
+        onKeyPressCapture?: KeyboardEventHandler<T> | undefined;
+        onKeyUp?: KeyboardEventHandler<T> | undefined;
+        onKeyUpCapture?: KeyboardEventHandler<T> | undefined;
+
+        // Media Events
+        onAbort?: ReactEventHandler<T> | undefined;
+        onAbortCapture?: ReactEventHandler<T> | undefined;
+        onCanPlay?: ReactEventHandler<T> | undefined;
+        onCanPlayCapture?: ReactEventHandler<T> | undefined;
+        onCanPlayThrough?: ReactEventHandler<T> | undefined;
+        onCanPlayThroughCapture?: ReactEventHandler<T> | undefined;
+        onDurationChange?: ReactEventHandler<T> | undefined;
+        onDurationChangeCapture?: ReactEventHandler<T> | undefined;
+        onEmptied?: ReactEventHandler<T> | undefined;
+        onEmptiedCapture?: ReactEventHandler<T> | undefined;
+        onEncrypted?: ReactEventHandler<T> | undefined;
+        onEncryptedCapture?: ReactEventHandler<T> | undefined;
+        onEnded?: ReactEventHandler<T> | undefined;
+        onEndedCapture?: ReactEventHandler<T> | undefined;
+        onLoadedData?: ReactEventHandler<T> | undefined;
+        onLoadedDataCapture?: ReactEventHandler<T> | undefined;
+        onLoadedMetadata?: ReactEventHandler<T> | undefined;
+        onLoadedMetadataCapture?: ReactEventHandler<T> | undefined;
+        onLoadStart?: ReactEventHandler<T> | undefined;
+        onLoadStartCapture?: ReactEventHandler<T> | undefined;
+        onPause?: ReactEventHandler<T> | undefined;
+        onPauseCapture?: ReactEventHandler<T> | undefined;
+        onPlay?: ReactEventHandler<T> | undefined;
+        onPlayCapture?: ReactEventHandler<T> | undefined;
+        onPlaying?: ReactEventHandler<T> | undefined;
+        onPlayingCapture?: ReactEventHandler<T> | undefined;
+        onProgress?: ReactEventHandler<T> | undefined;
+        onProgressCapture?: ReactEventHandler<T> | undefined;
+        onRateChange?: ReactEventHandler<T> | undefined;
+        onRateChangeCapture?: ReactEventHandler<T> | undefined;
+        onSeeked?: ReactEventHandler<T> | undefined;
+        onSeekedCapture?: ReactEventHandler<T> | undefined;
+        onSeeking?: ReactEventHandler<T> | undefined;
+        onSeekingCapture?: ReactEventHandler<T> | undefined;
+        onStalled?: ReactEventHandler<T> | undefined;
+        onStalledCapture?: ReactEventHandler<T> | undefined;
+        onSuspend?: ReactEventHandler<T> | undefined;
+        onSuspendCapture?: ReactEventHandler<T> | undefined;
+        onTimeUpdate?: ReactEventHandler<T> | undefined;
+        onTimeUpdateCapture?: ReactEventHandler<T> | undefined;
+        onVolumeChange?: ReactEventHandler<T> | undefined;
+        onVolumeChangeCapture?: ReactEventHandler<T> | undefined;
+        onWaiting?: ReactEventHandler<T> | undefined;
+        onWaitingCapture?: ReactEventHandler<T> | undefined;
+
+        // MouseEvents
+        onAuxClick?: MouseEventHandler<T> | undefined;
+        onAuxClickCapture?: MouseEventHandler<T> | undefined;
+        onClick?: MouseEventHandler<T> | undefined;
+        onClickCapture?: MouseEventHandler<T> | undefined;
+        onContextMenu?: MouseEventHandler<T> | undefined;
+        onContextMenuCapture?: MouseEventHandler<T> | undefined;
+        onDoubleClick?: MouseEventHandler<T> | undefined;
+        onDoubleClickCapture?: MouseEventHandler<T> | undefined;
+        onDrag?: DragEventHandler<T> | undefined;
+        onDragCapture?: DragEventHandler<T> | undefined;
+        onDragEnd?: DragEventHandler<T> | undefined;
+        onDragEndCapture?: DragEventHandler<T> | undefined;
+        onDragEnter?: DragEventHandler<T> | undefined;
+        onDragEnterCapture?: DragEventHandler<T> | undefined;
+        onDragExit?: DragEventHandler<T> | undefined;
+        onDragExitCapture?: DragEventHandler<T> | undefined;
+        onDragLeave?: DragEventHandler<T> | undefined;
+        onDragLeaveCapture?: DragEventHandler<T> | undefined;
+        onDragOver?: DragEventHandler<T> | undefined;
+        onDragOverCapture?: DragEventHandler<T> | undefined;
+        onDragStart?: DragEventHandler<T> | undefined;
+        onDragStartCapture?: DragEventHandler<T> | undefined;
+        onDrop?: DragEventHandler<T> | undefined;
+        onDropCapture?: DragEventHandler<T> | undefined;
+        onMouseDown?: MouseEventHandler<T> | undefined;
+        onMouseDownCapture?: MouseEventHandler<T> | undefined;
+        onMouseEnter?: MouseEventHandler<T> | undefined;
+        onMouseLeave?: MouseEventHandler<T> | undefined;
+        onMouseMove?: MouseEventHandler<T> | undefined;
+        onMouseMoveCapture?: MouseEventHandler<T> | undefined;
+        onMouseOut?: MouseEventHandler<T> | undefined;
+        onMouseOutCapture?: MouseEventHandler<T> | undefined;
+        onMouseOver?: MouseEventHandler<T> | undefined;
+        onMouseOverCapture?: MouseEventHandler<T> | undefined;
+        onMouseUp?: MouseEventHandler<T> | undefined;
+        onMouseUpCapture?: MouseEventHandler<T> | undefined;
+
+        // Selection Events
+        onSelect?: ReactEventHandler<T> | undefined;
+        onSelectCapture?: ReactEventHandler<T> | undefined;
+
+        // Touch Events
+        onTouchCancel?: TouchEventHandler<T> | undefined;
+        onTouchCancelCapture?: TouchEventHandler<T> | undefined;
+        onTouchEnd?: TouchEventHandler<T> | undefined;
+        onTouchEndCapture?: TouchEventHandler<T> | undefined;
+        onTouchMove?: TouchEventHandler<T> | undefined;
+        onTouchMoveCapture?: TouchEventHandler<T> | undefined;
+        onTouchStart?: TouchEventHandler<T> | undefined;
+        onTouchStartCapture?: TouchEventHandler<T> | undefined;
+
+        // Pointer Events
+        onPointerDown?: PointerEventHandler<T> | undefined;
+        onPointerDownCapture?: PointerEventHandler<T> | undefined;
+        onPointerMove?: PointerEventHandler<T> | undefined;
+        onPointerMoveCapture?: PointerEventHandler<T> | undefined;
+        onPointerUp?: PointerEventHandler<T> | undefined;
+        onPointerUpCapture?: PointerEventHandler<T> | undefined;
+        onPointerCancel?: PointerEventHandler<T> | undefined;
+        onPointerCancelCapture?: PointerEventHandler<T> | undefined;
+        onPointerEnter?: PointerEventHandler<T> | undefined;
+        onPointerEnterCapture?: PointerEventHandler<T> | undefined;
+        onPointerLeave?: PointerEventHandler<T> | undefined;
+        onPointerLeaveCapture?: PointerEventHandler<T> | undefined;
+        onPointerOver?: PointerEventHandler<T> | undefined;
+        onPointerOverCapture?: PointerEventHandler<T> | undefined;
+        onPointerOut?: PointerEventHandler<T> | undefined;
+        onPointerOutCapture?: PointerEventHandler<T> | undefined;
+        onGotPointerCapture?: PointerEventHandler<T> | undefined;
+        onGotPointerCaptureCapture?: PointerEventHandler<T> | undefined;
+        onLostPointerCapture?: PointerEventHandler<T> | undefined;
+        onLostPointerCaptureCapture?: PointerEventHandler<T> | undefined;
+
+        // UI Events
+        onScroll?: UIEventHandler<T> | undefined;
+        onScrollCapture?: UIEventHandler<T> | undefined;
+
+        // Wheel Events
+        onWheel?: WheelEventHandler<T> | undefined;
+        onWheelCapture?: WheelEventHandler<T> | undefined;
+
+        // Animation Events
+        onAnimationStart?: AnimationEventHandler<T> | undefined;
+        onAnimationStartCapture?: AnimationEventHandler<T> | undefined;
+        onAnimationEnd?: AnimationEventHandler<T> | undefined;
+        onAnimationEndCapture?: AnimationEventHandler<T> | undefined;
+        onAnimationIteration?: AnimationEventHandler<T> | undefined;
+        onAnimationIterationCapture?: AnimationEventHandler<T> | undefined;
+
+        // Transition Events
+        onTransitionEnd?: TransitionEventHandler<T> | undefined;
+        onTransitionEndCapture?: TransitionEventHandler<T> | undefined;
+    }
+
+    export interface CSSProperties extends CSS.Properties<string | number> {
+        /**
+         * The index signature was removed to enable closed typing for style
+         * using CSSType. You're able to use type assertion or module augmentation
+         * to add properties or an index signature of your own.
+         *
+         * For examples and more information, visit:
+         * https://github.com/frenic/csstype#what-should-i-do-when-i-get-type-errors
+         */
+    }
+
+    // All the WAI-ARIA 1.1 attributes from https://www.w3.org/TR/wai-aria-1.1/
+    interface AriaAttributes {
+        /** Identifies the currently active element when DOM focus is on a composite widget, textbox, group, or application. */
+        'aria-activedescendant'?: string | undefined;
+        /** Indicates whether assistive technologies will present all, or only parts of, the changed region based on the change notifications defined by the aria-relevant attribute. */
+        'aria-atomic'?: Booleanish | undefined;
+        /**
+         * Indicates whether inputting text could trigger display of one or more predictions of the user's intended value for an input and specifies how predictions would be
+         * presented if they are made.
+         */
+        'aria-autocomplete'?: 'none' | 'inline' | 'list' | 'both' | undefined;
+        /** Indicates an element is being modified and that assistive technologies MAY want to wait until the modifications are complete before exposing them to the user. */
+        'aria-busy'?: Booleanish | undefined;
+        /**
+         * Indicates the current "checked" state of checkboxes, radio buttons, and other widgets.
+         * @see aria-pressed @see aria-selected.
+         */
+        'aria-checked'?: boolean | 'false' | 'mixed' | 'true' | undefined;
+        /**
+         * Defines the total number of columns in a table, grid, or treegrid.
+         * @see aria-colindex.
+         */
+        'aria-colcount'?: number | undefined;
+        /**
+         * Defines an element's column index or position with respect to the total number of columns within a table, grid, or treegrid.
+         * @see aria-colcount @see aria-colspan.
+         */
+        'aria-colindex'?: number | undefined;
+        /**
+         * Defines the number of columns spanned by a cell or gridcell within a table, grid, or treegrid.
+         * @see aria-colindex @see aria-rowspan.
+         */
+        'aria-colspan'?: number | undefined;
+        /**
+         * Identifies the element (or elements) whose contents or presence are controlled by the current element.
+         * @see aria-owns.
+         */
+        'aria-controls'?: string | undefined;
+        /** Indicates the element that represents the current item within a container or set of related elements. */
+        'aria-current'?: boolean | 'false' | 'true' | 'page' | 'step' | 'location' | 'date' | 'time' | undefined;
+        /**
+         * Identifies the element (or elements) that describes the object.
+         * @see aria-labelledby
+         */
+        'aria-describedby'?: string | undefined;
+        /**
+         * Identifies the element that provides a detailed, extended description for the object.
+         * @see aria-describedby.
+         */
+        'aria-details'?: string | undefined;
+        /**
+         * Indicates that the element is perceivable but disabled, so it is not editable or otherwise operable.
+         * @see aria-hidden @see aria-readonly.
+         */
+        'aria-disabled'?: Booleanish | undefined;
+        /**
+         * Indicates what functions can be performed when a dragged object is released on the drop target.
+         * @deprecated in ARIA 1.1
+         */
+        'aria-dropeffect'?: 'none' | 'copy' | 'execute' | 'link' | 'move' | 'popup' | undefined;
+        /**
+         * Identifies the element that provides an error message for the object.
+         * @see aria-invalid @see aria-describedby.
+         */
+        'aria-errormessage'?: string | undefined;
+        /** Indicates whether the element, or another grouping element it controls, is currently expanded or collapsed. */
+        'aria-expanded'?: Booleanish | undefined;
+        /**
+         * Identifies the next element (or elements) in an alternate reading order of content which, at the user's discretion,
+         * allows assistive technology to override the general default of reading in document source order.
+         */
+        'aria-flowto'?: string | undefined;
+        /**
+         * Indicates an element's "grabbed" state in a drag-and-drop operation.
+         * @deprecated in ARIA 1.1
+         */
+        'aria-grabbed'?: Booleanish | undefined;
+        /** Indicates the availability and type of interactive popup element, such as menu or dialog, that can be triggered by an element. */
+        'aria-haspopup'?: boolean | 'false' | 'true' | 'menu' | 'listbox' | 'tree' | 'grid' | 'dialog' | undefined;
+        /**
+         * Indicates whether the element is exposed to an accessibility API.
+         * @see aria-disabled.
+         */
+        'aria-hidden'?: Booleanish | undefined;
+        /**
+         * Indicates the entered value does not conform to the format expected by the application.
+         * @see aria-errormessage.
+         */
+        'aria-invalid'?: boolean | 'false' | 'true' | 'grammar' | 'spelling' | undefined;
+        /** Indicates keyboard shortcuts that an author has implemented to activate or give focus to an element. */
+        'aria-keyshortcuts'?: string | undefined;
+        /**
+         * Defines a string value that labels the current element.
+         * @see aria-labelledby.
+         */
+        'aria-label'?: string | undefined;
+        /**
+         * Identifies the element (or elements) that labels the current element.
+         * @see aria-describedby.
+         */
+        'aria-labelledby'?: string | undefined;
+        /** Defines the hierarchical level of an element within a structure. */
+        'aria-level'?: number | undefined;
+        /** Indicates that an element will be updated, and describes the types of updates the user agents, assistive technologies, and user can expect from the live region. */
+        'aria-live'?: 'off' | 'assertive' | 'polite' | undefined;
+        /** Indicates whether an element is modal when displayed. */
+        'aria-modal'?: Booleanish | undefined;
+        /** Indicates whether a text box accepts multiple lines of input or only a single line. */
+        'aria-multiline'?: Booleanish | undefined;
+        /** Indicates that the user may select more than one item from the current selectable descendants. */
+        'aria-multiselectable'?: Booleanish | undefined;
+        /** Indicates whether the element's orientation is horizontal, vertical, or unknown/ambiguous. */
+        'aria-orientation'?: 'horizontal' | 'vertical' | undefined;
+        /**
+         * Identifies an element (or elements) in order to define a visual, functional, or contextual parent/child relationship
+         * between DOM elements where the DOM hierarchy cannot be used to represent the relationship.
+         * @see aria-controls.
+         */
+        'aria-owns'?: string | undefined;
+        /**
+         * Defines a short hint (a word or short phrase) intended to aid the user with data entry when the control has no value.
+         * A hint could be a sample value or a brief description of the expected format.
+         */
+        'aria-placeholder'?: string | undefined;
+        /**
+         * Defines an element's number or position in the current set of listitems or treeitems. Not required if all elements in the set are present in the DOM.
+         * @see aria-setsize.
+         */
+        'aria-posinset'?: number | undefined;
+        /**
+         * Indicates the current "pressed" state of toggle buttons.
+         * @see aria-checked @see aria-selected.
+         */
+        'aria-pressed'?: boolean | 'false' | 'mixed' | 'true' | undefined;
+        /**
+         * Indicates that the element is not editable, but is otherwise operable.
+         * @see aria-disabled.
+         */
+        'aria-readonly'?: Booleanish | undefined;
+        /**
+         * Indicates what notifications the user agent will trigger when the accessibility tree within a live region is modified.
+         * @see aria-atomic.
+         */
+        'aria-relevant'?: 'additions' | 'additions removals' | 'additions text' | 'all' | 'removals' | 'removals additions' | 'removals text' | 'text' | 'text additions' | 'text removals' | undefined;
+        /** Indicates that user input is required on the element before a form may be submitted. */
+        'aria-required'?: Booleanish | undefined;
+        /** Defines a human-readable, author-localized description for the role of an element. */
+        'aria-roledescription'?: string | undefined;
+        /**
+         * Defines the total number of rows in a table, grid, or treegrid.
+         * @see aria-rowindex.
+         */
+        'aria-rowcount'?: number | undefined;
+        /**
+         * Defines an element's row index or position with respect to the total number of rows within a table, grid, or treegrid.
+         * @see aria-rowcount @see aria-rowspan.
+         */
+        'aria-rowindex'?: number | undefined;
+        /**
+         * Defines the number of rows spanned by a cell or gridcell within a table, grid, or treegrid.
+         * @see aria-rowindex @see aria-colspan.
+         */
+        'aria-rowspan'?: number | undefined;
+        /**
+         * Indicates the current "selected" state of various widgets.
+         * @see aria-checked @see aria-pressed.
+         */
+        'aria-selected'?: Booleanish | undefined;
+        /**
+         * Defines the number of items in the current set of listitems or treeitems. Not required if all elements in the set are present in the DOM.
+         * @see aria-posinset.
+         */
+        'aria-setsize'?: number | undefined;
+        /** Indicates if items in a table or grid are sorted in ascending or descending order. */
+        'aria-sort'?: 'none' | 'ascending' | 'descending' | 'other' | undefined;
+        /** Defines the maximum allowed value for a range widget. */
+        'aria-valuemax'?: number | undefined;
+        /** Defines the minimum allowed value for a range widget. */
+        'aria-valuemin'?: number | undefined;
+        /**
+         * Defines the current value for a range widget.
+         * @see aria-valuetext.
+         */
+        'aria-valuenow'?: number | undefined;
+        /** Defines the human readable text alternative of aria-valuenow for a range widget. */
+        'aria-valuetext'?: string | undefined;
+    }
+
+    // All the WAI-ARIA 1.1 role attribute values from https://www.w3.org/TR/wai-aria-1.1/#role_definitions
+    type AriaRole =
+        | 'alert'
+        | 'alertdialog'
+        | 'application'
+        | 'article'
+        | 'banner'
+        | 'button'
+        | 'cell'
+        | 'checkbox'
+        | 'columnheader'
+        | 'combobox'
+        | 'complementary'
+        | 'contentinfo'
+        | 'definition'
+        | 'dialog'
+        | 'directory'
+        | 'document'
+        | 'feed'
+        | 'figure'
+        | 'form'
+        | 'grid'
+        | 'gridcell'
+        | 'group'
+        | 'heading'
+        | 'img'
+        | 'link'
+        | 'list'
+        | 'listbox'
+        | 'listitem'
+        | 'log'
+        | 'main'
+        | 'marquee'
+        | 'math'
+        | 'menu'
+        | 'menubar'
+        | 'menuitem'
+        | 'menuitemcheckbox'
+        | 'menuitemradio'
+        | 'navigation'
+        | 'none'
+        | 'note'
+        | 'option'
+        | 'presentation'
+        | 'progressbar'
+        | 'radio'
+        | 'radiogroup'
+        | 'region'
+        | 'row'
+        | 'rowgroup'
+        | 'rowheader'
+        | 'scrollbar'
+        | 'search'
+        | 'searchbox'
+        | 'separator'
+        | 'slider'
+        | 'spinbutton'
+        | 'status'
+        | 'switch'
+        | 'tab'
+        | 'table'
+        | 'tablist'
+        | 'tabpanel'
+        | 'term'
+        | 'textbox'
+        | 'timer'
+        | 'toolbar'
+        | 'tooltip'
+        | 'tree'
+        | 'treegrid'
+        | 'treeitem'
+        | (string & {});
+
+    interface HTMLAttributes<T> extends AriaAttributes, DOMAttributes<T> {
+        // React-specific Attributes
+        defaultChecked?: boolean | undefined;
+        defaultValue?: string | number | ReadonlyArray<string> | undefined;
+        suppressContentEditableWarning?: boolean | undefined;
+        suppressHydrationWarning?: boolean | undefined;
+
+        // Standard HTML Attributes
+        accessKey?: string | undefined;
+        className?: string | undefined;
+        contentEditable?: Booleanish | "inherit" | undefined;
+        contextMenu?: string | undefined;
+        dir?: string | undefined;
+        draggable?: Booleanish | undefined;
+        hidden?: boolean | undefined;
+        id?: string | undefined;
+        lang?: string | undefined;
+        placeholder?: string | undefined;
+        slot?: string | undefined;
+        spellCheck?: Booleanish | undefined;
+        style?: CSSProperties | undefined;
+        tabIndex?: number | undefined;
+        title?: string | undefined;
+        translate?: 'yes' | 'no' | undefined;
+
+        // Unknown
+        radioGroup?: string | undefined; // <command>, <menuitem>
+
+        // WAI-ARIA
+        role?: AriaRole | undefined;
+
+        // RDFa Attributes
+        about?: string | undefined;
+        datatype?: string | undefined;
+        inlist?: any;
+        prefix?: string | undefined;
+        property?: string | undefined;
+        resource?: string | undefined;
+        typeof?: string | undefined;
+        vocab?: string | undefined;
+
+        // Non-standard Attributes
+        autoCapitalize?: string | undefined;
+        autoCorrect?: string | undefined;
+        autoSave?: string | undefined;
+        color?: string | undefined;
+        itemProp?: string | undefined;
+        itemScope?: boolean | undefined;
+        itemType?: string | undefined;
+        itemID?: string | undefined;
+        itemRef?: string | undefined;
+        results?: number | undefined;
+        security?: string | undefined;
+        unselectable?: 'on' | 'off' | undefined;
+
+        // Living Standard
+        /**
+         * Hints at the type of data that might be entered by the user while editing the element or its contents
+         * @see https://html.spec.whatwg.org/multipage/interaction.html#input-modalities:-the-inputmode-attribute
+         */
+        inputMode?: 'none' | 'text' | 'tel' | 'url' | 'email' | 'numeric' | 'decimal' | 'search' | undefined;
+        /**
+         * Specify that a standard HTML element should behave like a defined custom built-in element
+         * @see https://html.spec.whatwg.org/multipage/custom-elements.html#attr-is
+         */
+        is?: string | undefined;
+    }
+
+    interface AllHTMLAttributes<T> extends HTMLAttributes<T> {
+        // Standard HTML Attributes
+        accept?: string | undefined;
+        acceptCharset?: string | undefined;
+        action?: string | undefined;
+        allowFullScreen?: boolean | undefined;
+        allowTransparency?: boolean | undefined;
+        alt?: string | undefined;
+        as?: string | undefined;
+        async?: boolean | undefined;
+        autoComplete?: string | undefined;
+        autoFocus?: boolean | undefined;
+        autoPlay?: boolean | undefined;
+        capture?: boolean | 'user' | 'environment' | undefined;
+        cellPadding?: number | string | undefined;
+        cellSpacing?: number | string | undefined;
+        charSet?: string | undefined;
+        challenge?: string | undefined;
+        checked?: boolean | undefined;
+        cite?: string | undefined;
+        classID?: string | undefined;
+        cols?: number | undefined;
+        colSpan?: number | undefined;
+        content?: string | undefined;
+        controls?: boolean | undefined;
+        coords?: string | undefined;
+        crossOrigin?: string | undefined;
+        data?: string | undefined;
+        dateTime?: string | undefined;
+        default?: boolean | undefined;
+        defer?: boolean | undefined;
+        disabled?: boolean | undefined;
+        download?: any;
+        encType?: string | undefined;
+        form?: string | undefined;
+        formAction?: string | undefined;
+        formEncType?: string | undefined;
+        formMethod?: string | undefined;
+        formNoValidate?: boolean | undefined;
+        formTarget?: string | undefined;
+        frameBorder?: number | string | undefined;
+        headers?: string | undefined;
+        height?: number | string | undefined;
+        high?: number | undefined;
+        href?: string | undefined;
+        hrefLang?: string | undefined;
+        htmlFor?: string | undefined;
+        httpEquiv?: string | undefined;
+        integrity?: string | undefined;
+        keyParams?: string | undefined;
+        keyType?: string | undefined;
+        kind?: string | undefined;
+        label?: string | undefined;
+        list?: string | undefined;
+        loop?: boolean | undefined;
+        low?: number | undefined;
+        manifest?: string | undefined;
+        marginHeight?: number | undefined;
+        marginWidth?: number | undefined;
+        max?: number | string | undefined;
+        maxLength?: number | undefined;
+        media?: string | undefined;
+        mediaGroup?: string | undefined;
+        method?: string | undefined;
+        min?: number | string | undefined;
+        minLength?: number | undefined;
+        multiple?: boolean | undefined;
+        muted?: boolean | undefined;
+        name?: string | undefined;
+        nonce?: string | undefined;
+        noValidate?: boolean | undefined;
+        open?: boolean | undefined;
+        optimum?: number | undefined;
+        pattern?: string | undefined;
+        placeholder?: string | undefined;
+        playsInline?: boolean | undefined;
+        poster?: string | undefined;
+        preload?: string | undefined;
+        readOnly?: boolean | undefined;
+        rel?: string | undefined;
+        required?: boolean | undefined;
+        reversed?: boolean | undefined;
+        rows?: number | undefined;
+        rowSpan?: number | undefined;
+        sandbox?: string | undefined;
+        scope?: string | undefined;
+        scoped?: boolean | undefined;
+        scrolling?: string | undefined;
+        seamless?: boolean | undefined;
+        selected?: boolean | undefined;
+        shape?: string | undefined;
+        size?: number | undefined;
+        sizes?: string | undefined;
+        span?: number | undefined;
+        src?: string | undefined;
+        srcDoc?: string | undefined;
+        srcLang?: string | undefined;
+        srcSet?: string | undefined;
+        start?: number | undefined;
+        step?: number | string | undefined;
+        summary?: string | undefined;
+        target?: string | undefined;
+        type?: string | undefined;
+        useMap?: string | undefined;
+        value?: string | ReadonlyArray<string> | number | undefined;
+        width?: number | string | undefined;
+        wmode?: string | undefined;
+        wrap?: string | undefined;
+    }
+
+    type HTMLAttributeReferrerPolicy =
+        | ''
+        | 'no-referrer'
+        | 'no-referrer-when-downgrade'
+        | 'origin'
+        | 'origin-when-cross-origin'
+        | 'same-origin'
+        | 'strict-origin'
+        | 'strict-origin-when-cross-origin'
+        | 'unsafe-url';
+
+    type HTMLAttributeAnchorTarget =
+        | '_self'
+        | '_blank'
+        | '_parent'
+        | '_top'
+        | (string & {});
+
+    interface AnchorHTMLAttributes<T> extends HTMLAttributes<T> {
+        download?: any;
+        href?: string | undefined;
+        hrefLang?: string | undefined;
+        media?: string | undefined;
+        ping?: string | undefined;
+        rel?: string | undefined;
+        target?: HTMLAttributeAnchorTarget | undefined;
+        type?: string | undefined;
+        referrerPolicy?: HTMLAttributeReferrerPolicy | undefined;
+    }
+
+    interface AudioHTMLAttributes<T> extends MediaHTMLAttributes<T> {}
+
+    interface AreaHTMLAttributes<T> extends HTMLAttributes<T> {
+        alt?: string | undefined;
+        coords?: string | undefined;
+        download?: any;
+        href?: string | undefined;
+        hrefLang?: string | undefined;
+        media?: string | undefined;
+        referrerPolicy?: HTMLAttributeReferrerPolicy | undefined;
+        rel?: string | undefined;
+        shape?: string | undefined;
+        target?: string | undefined;
+    }
+
+    interface BaseHTMLAttributes<T> extends HTMLAttributes<T> {
+        href?: string | undefined;
+        target?: string | undefined;
+    }
+
+    interface BlockquoteHTMLAttributes<T> extends HTMLAttributes<T> {
+        cite?: string | undefined;
+    }
+
+    interface ButtonHTMLAttributes<T> extends HTMLAttributes<T> {
+        autoFocus?: boolean | undefined;
+        disabled?: boolean | undefined;
+        form?: string | undefined;
+        formAction?: string | undefined;
+        formEncType?: string | undefined;
+        formMethod?: string | undefined;
+        formNoValidate?: boolean | undefined;
+        formTarget?: string | undefined;
+        name?: string | undefined;
+        type?: 'submit' | 'reset' | 'button' | undefined;
+        value?: string | ReadonlyArray<string> | number | undefined;
+    }
+
+    interface CanvasHTMLAttributes<T> extends HTMLAttributes<T> {
+        height?: number | string | undefined;
+        width?: number | string | undefined;
+    }
+
+    interface ColHTMLAttributes<T> extends HTMLAttributes<T> {
+        span?: number | undefined;
+        width?: number | string | undefined;
+    }
+
+    interface ColgroupHTMLAttributes<T> extends HTMLAttributes<T> {
+        span?: number | undefined;
+    }
+
+    interface DataHTMLAttributes<T> extends HTMLAttributes<T> {
+        value?: string | ReadonlyArray<string> | number | undefined;
+    }
+
+    interface DetailsHTMLAttributes<T> extends HTMLAttributes<T> {
+        open?: boolean | undefined;
+        onToggle?: ReactEventHandler<T> | undefined;
+    }
+
+    interface DelHTMLAttributes<T> extends HTMLAttributes<T> {
+        cite?: string | undefined;
+        dateTime?: string | undefined;
+    }
+
+    interface DialogHTMLAttributes<T> extends HTMLAttributes<T> {
+        open?: boolean | undefined;
+    }
+
+    interface EmbedHTMLAttributes<T> extends HTMLAttributes<T> {
+        height?: number | string | undefined;
+        src?: string | undefined;
+        type?: string | undefined;
+        width?: number | string | undefined;
+    }
+
+    interface FieldsetHTMLAttributes<T> extends HTMLAttributes<T> {
+        disabled?: boolean | undefined;
+        form?: string | undefined;
+        name?: string | undefined;
+    }
+
+    interface FormHTMLAttributes<T> extends HTMLAttributes<T> {
+        acceptCharset?: string | undefined;
+        action?: string | undefined;
+        autoComplete?: string | undefined;
+        encType?: string | undefined;
+        method?: string | undefined;
+        name?: string | undefined;
+        noValidate?: boolean | undefined;
+        target?: string | undefined;
+    }
+
+    interface HtmlHTMLAttributes<T> extends HTMLAttributes<T> {
+        manifest?: string | undefined;
+    }
+
+    interface IframeHTMLAttributes<T> extends HTMLAttributes<T> {
+        allow?: string | undefined;
+        allowFullScreen?: boolean | undefined;
+        allowTransparency?: boolean | undefined;
+        /** @deprecated */
+        frameBorder?: number | string | undefined;
+        height?: number | string | undefined;
+        loading?: "eager" | "lazy" | undefined;
+        /** @deprecated */
+        marginHeight?: number | undefined;
+        /** @deprecated */
+        marginWidth?: number | undefined;
+        name?: string | undefined;
+        referrerPolicy?: HTMLAttributeReferrerPolicy | undefined;
+        sandbox?: string | undefined;
+        /** @deprecated */
+        scrolling?: string | undefined;
+        seamless?: boolean | undefined;
+        src?: string | undefined;
+        srcDoc?: string | undefined;
+        width?: number | string | undefined;
+    }
+
+    interface ImgHTMLAttributes<T> extends HTMLAttributes<T> {
+        alt?: string | undefined;
+        crossOrigin?: "anonymous" | "use-credentials" | "" | undefined;
+        decoding?: "async" | "auto" | "sync" | undefined;
+        height?: number | string | undefined;
+        loading?: "eager" | "lazy" | undefined;
+        referrerPolicy?: HTMLAttributeReferrerPolicy | undefined;
+        sizes?: string | undefined;
+        src?: string | undefined;
+        srcSet?: string | undefined;
+        useMap?: string | undefined;
+        width?: number | string | undefined;
+    }
+
+    interface InsHTMLAttributes<T> extends HTMLAttributes<T> {
+        cite?: string | undefined;
+        dateTime?: string | undefined;
+    }
+
+    type HTMLInputTypeAttribute =
+        | 'button'
+        | 'checkbox'
+        | 'color'
+        | 'date'
+        | 'datetime-local'
+        | 'email'
+        | 'file'
+        | 'hidden'
+        | 'image'
+        | 'month'
+        | 'number'
+        | 'password'
+        | 'radio'
+        | 'range'
+        | 'reset'
+        | 'search'
+        | 'submit'
+        | 'tel'
+        | 'text'
+        | 'time'
+        | 'url'
+        | 'week'
+        | (string & {});
+
+    interface InputHTMLAttributes<T> extends HTMLAttributes<T> {
+        accept?: string | undefined;
+        alt?: string | undefined;
+        autoComplete?: string | undefined;
+        autoFocus?: boolean | undefined;
+        capture?: boolean | 'user' | 'environment' | undefined; // https://www.w3.org/TR/html-media-capture/#the-capture-attribute
+        checked?: boolean | undefined;
+        crossOrigin?: string | undefined;
+        disabled?: boolean | undefined;
+        enterKeyHint?: 'enter' | 'done' | 'go' | 'next' | 'previous' | 'search' | 'send' | undefined;
+        form?: string | undefined;
+        formAction?: string | undefined;
+        formEncType?: string | undefined;
+        formMethod?: string | undefined;
+        formNoValidate?: boolean | undefined;
+        formTarget?: string | undefined;
+        height?: number | string | undefined;
+        list?: string | undefined;
+        max?: number | string | undefined;
+        maxLength?: number | undefined;
+        min?: number | string | undefined;
+        minLength?: number | undefined;
+        multiple?: boolean | undefined;
+        name?: string | undefined;
+        pattern?: string | undefined;
+        placeholder?: string | undefined;
+        readOnly?: boolean | undefined;
+        required?: boolean | undefined;
+        size?: number | undefined;
+        src?: string | undefined;
+        step?: number | string | undefined;
+        type?: HTMLInputTypeAttribute | undefined;
+        value?: string | ReadonlyArray<string> | number | undefined;
+        width?: number | string | undefined;
+
+        onChange?: ChangeEventHandler<T> | undefined;
+    }
+
+    interface KeygenHTMLAttributes<T> extends HTMLAttributes<T> {
+        autoFocus?: boolean | undefined;
+        challenge?: string | undefined;
+        disabled?: boolean | undefined;
+        form?: string | undefined;
+        keyType?: string | undefined;
+        keyParams?: string | undefined;
+        name?: string | undefined;
+    }
+
+    interface LabelHTMLAttributes<T> extends HTMLAttributes<T> {
+        form?: string | undefined;
+        htmlFor?: string | undefined;
+    }
+
+    interface LiHTMLAttributes<T> extends HTMLAttributes<T> {
+        value?: string | ReadonlyArray<string> | number | undefined;
+    }
+
+    interface LinkHTMLAttributes<T> extends HTMLAttributes<T> {
+        as?: string | undefined;
+        crossOrigin?: string | undefined;
+        href?: string | undefined;
+        hrefLang?: string | undefined;
+        integrity?: string | undefined;
+        media?: string | undefined;
+        imageSrcSet?: string | undefined;
+        referrerPolicy?: HTMLAttributeReferrerPolicy | undefined;
+        rel?: string | undefined;
+        sizes?: string | undefined;
+        type?: string | undefined;
+        charSet?: string | undefined;
+    }
+
+    interface MapHTMLAttributes<T> extends HTMLAttributes<T> {
+        name?: string | undefined;
+    }
+
+    interface MenuHTMLAttributes<T> extends HTMLAttributes<T> {
+        type?: string | undefined;
+    }
+
+    interface MediaHTMLAttributes<T> extends HTMLAttributes<T> {
+        autoPlay?: boolean | undefined;
+        controls?: boolean | undefined;
+        controlsList?: string | undefined;
+        crossOrigin?: string | undefined;
+        loop?: boolean | undefined;
+        mediaGroup?: string | undefined;
+        muted?: boolean | undefined;
+        playsInline?: boolean | undefined;
+        preload?: string | undefined;
+        src?: string | undefined;
+    }
+
+    interface MetaHTMLAttributes<T> extends HTMLAttributes<T> {
+        charSet?: string | undefined;
+        content?: string | undefined;
+        httpEquiv?: string | undefined;
+        name?: string | undefined;
+        media?: string | undefined;
+    }
+
+    interface MeterHTMLAttributes<T> extends HTMLAttributes<T> {
+        form?: string | undefined;
+        high?: number | undefined;
+        low?: number | undefined;
+        max?: number | string | undefined;
+        min?: number | string | undefined;
+        optimum?: number | undefined;
+        value?: string | ReadonlyArray<string> | number | undefined;
+    }
+
+    interface QuoteHTMLAttributes<T> extends HTMLAttributes<T> {
+        cite?: string | undefined;
+    }
+
+    interface ObjectHTMLAttributes<T> extends HTMLAttributes<T> {
+        classID?: string | undefined;
+        data?: string | undefined;
+        form?: string | undefined;
+        height?: number | string | undefined;
+        name?: string | undefined;
+        type?: string | undefined;
+        useMap?: string | undefined;
+        width?: number | string | undefined;
+        wmode?: string | undefined;
+    }
+
+    interface OlHTMLAttributes<T> extends HTMLAttributes<T> {
+        reversed?: boolean | undefined;
+        start?: number | undefined;
+        type?: '1' | 'a' | 'A' | 'i' | 'I' | undefined;
+    }
+
+    interface OptgroupHTMLAttributes<T> extends HTMLAttributes<T> {
+        disabled?: boolean | undefined;
+        label?: string | undefined;
+    }
+
+    interface OptionHTMLAttributes<T> extends HTMLAttributes<T> {
+        disabled?: boolean | undefined;
+        label?: string | undefined;
+        selected?: boolean | undefined;
+        value?: string | ReadonlyArray<string> | number | undefined;
+    }
+
+    interface OutputHTMLAttributes<T> extends HTMLAttributes<T> {
+        form?: string | undefined;
+        htmlFor?: string | undefined;
+        name?: string | undefined;
+    }
+
+    interface ParamHTMLAttributes<T> extends HTMLAttributes<T> {
+        name?: string | undefined;
+        value?: string | ReadonlyArray<string> | number | undefined;
+    }
+
+    interface ProgressHTMLAttributes<T> extends HTMLAttributes<T> {
+        max?: number | string | undefined;
+        value?: string | ReadonlyArray<string> | number | undefined;
+    }
+
+    interface SlotHTMLAttributes<T> extends HTMLAttributes<T> {
+        name?: string | undefined;
+    }
+
+    interface ScriptHTMLAttributes<T> extends HTMLAttributes<T> {
+        async?: boolean | undefined;
+        /** @deprecated */
+        charSet?: string | undefined;
+        crossOrigin?: string | undefined;
+        defer?: boolean | undefined;
+        integrity?: string | undefined;
+        noModule?: boolean | undefined;
+        nonce?: string | undefined;
+        referrerPolicy?: HTMLAttributeReferrerPolicy | undefined;
+        src?: string | undefined;
+        type?: string | undefined;
+    }
+
+    interface SelectHTMLAttributes<T> extends HTMLAttributes<T> {
+        autoComplete?: string | undefined;
+        autoFocus?: boolean | undefined;
+        disabled?: boolean | undefined;
+        form?: string | undefined;
+        multiple?: boolean | undefined;
+        name?: string | undefined;
+        required?: boolean | undefined;
+        size?: number | undefined;
+        value?: string | ReadonlyArray<string> | number | undefined;
+        onChange?: ChangeEventHandler<T> | undefined;
+    }
+
+    interface SourceHTMLAttributes<T> extends HTMLAttributes<T> {
+        height?: number | string | undefined;
+        media?: string | undefined;
+        sizes?: string | undefined;
+        src?: string | undefined;
+        srcSet?: string | undefined;
+        type?: string | undefined;
+        width?: number | string | undefined;
+    }
+
+    interface StyleHTMLAttributes<T> extends HTMLAttributes<T> {
+        media?: string | undefined;
+        nonce?: string | undefined;
+        scoped?: boolean | undefined;
+        type?: string | undefined;
+    }
+
+    interface TableHTMLAttributes<T> extends HTMLAttributes<T> {
+        cellPadding?: number | string | undefined;
+        cellSpacing?: number | string | undefined;
+        summary?: string | undefined;
+        width?: number | string | undefined;
+    }
+
+    interface TextareaHTMLAttributes<T> extends HTMLAttributes<T> {
+        autoComplete?: string | undefined;
+        autoFocus?: boolean | undefined;
+        cols?: number | undefined;
+        dirName?: string | undefined;
+        disabled?: boolean | undefined;
+        form?: string | undefined;
+        maxLength?: number | undefined;
+        minLength?: number | undefined;
+        name?: string | undefined;
+        placeholder?: string | undefined;
+        readOnly?: boolean | undefined;
+        required?: boolean | undefined;
+        rows?: number | undefined;
+        value?: string | ReadonlyArray<string> | number | undefined;
+        wrap?: string | undefined;
+
+        onChange?: ChangeEventHandler<T> | undefined;
+    }
+
+    interface TdHTMLAttributes<T> extends HTMLAttributes<T> {
+        align?: "left" | "center" | "right" | "justify" | "char" | undefined;
+        colSpan?: number | undefined;
+        headers?: string | undefined;
+        rowSpan?: number | undefined;
+        scope?: string | undefined;
+        abbr?: string | undefined;
+        height?: number | string | undefined;
+        width?: number | string | undefined;
+        valign?: "top" | "middle" | "bottom" | "baseline" | undefined;
+    }
+
+    interface ThHTMLAttributes<T> extends HTMLAttributes<T> {
+        align?: "left" | "center" | "right" | "justify" | "char" | undefined;
+        colSpan?: number | undefined;
+        headers?: string | undefined;
+        rowSpan?: number | undefined;
+        scope?: string | undefined;
+        abbr?: string | undefined;
+    }
+
+    interface TimeHTMLAttributes<T> extends HTMLAttributes<T> {
+        dateTime?: string | undefined;
+    }
+
+    interface TrackHTMLAttributes<T> extends HTMLAttributes<T> {
+        default?: boolean | undefined;
+        kind?: string | undefined;
+        label?: string | undefined;
+        src?: string | undefined;
+        srcLang?: string | undefined;
+    }
+
+    interface VideoHTMLAttributes<T> extends MediaHTMLAttributes<T> {
+        height?: number | string | undefined;
+        playsInline?: boolean | undefined;
+        poster?: string | undefined;
+        width?: number | string | undefined;
+        disablePictureInPicture?: boolean | undefined;
+        disableRemotePlayback?: boolean | undefined;
+    }
+
+    // this list is "complete" in that it contains every SVG attribute
+    // that React supports, but the types can be improved.
+    // Full list here: https://facebook.github.io/react/docs/dom-elements.html
+    //
+    // The three broad type categories are (in order of restrictiveness):
+    //   - "number | string"
+    //   - "string"
+    //   - union of string literals
+    interface SVGAttributes<T> extends AriaAttributes, DOMAttributes<T> {
+        // Attributes which also defined in HTMLAttributes
+        // See comment in SVGDOMPropertyConfig.js
+        className?: string | undefined;
+        color?: string | undefined;
+        height?: number | string | undefined;
+        id?: string | undefined;
+        lang?: string | undefined;
+        max?: number | string | undefined;
+        media?: string | undefined;
+        method?: string | undefined;
+        min?: number | string | undefined;
+        name?: string | undefined;
+        style?: CSSProperties | undefined;
+        target?: string | undefined;
+        type?: string | undefined;
+        width?: number | string | undefined;
+
+        // Other HTML properties supported by SVG elements in browsers
+        role?: AriaRole | undefined;
+        tabIndex?: number | undefined;
+        crossOrigin?: "anonymous" | "use-credentials" | "" | undefined;
+
+        // SVG Specific attributes
+        accentHeight?: number | string | undefined;
+        accumulate?: "none" | "sum" | undefined;
+        additive?: "replace" | "sum" | undefined;
+        alignmentBaseline?: "auto" | "baseline" | "before-edge" | "text-before-edge" | "middle" | "central" | "after-edge" |
+        "text-after-edge" | "ideographic" | "alphabetic" | "hanging" | "mathematical" | "inherit" | undefined;
+        allowReorder?: "no" | "yes" | undefined;
+        alphabetic?: number | string | undefined;
+        amplitude?: number | string | undefined;
+        arabicForm?: "initial" | "medial" | "terminal" | "isolated" | undefined;
+        ascent?: number | string | undefined;
+        attributeName?: string | undefined;
+        attributeType?: string | undefined;
+        autoReverse?: Booleanish | undefined;
+        azimuth?: number | string | undefined;
+        baseFrequency?: number | string | undefined;
+        baselineShift?: number | string | undefined;
+        baseProfile?: number | string | undefined;
+        bbox?: number | string | undefined;
+        begin?: number | string | undefined;
+        bias?: number | string | undefined;
+        by?: number | string | undefined;
+        calcMode?: number | string | undefined;
+        capHeight?: number | string | undefined;
+        clip?: number | string | undefined;
+        clipPath?: string | undefined;
+        clipPathUnits?: number | string | undefined;
+        clipRule?: number | string | undefined;
+        colorInterpolation?: number | string | undefined;
+        colorInterpolationFilters?: "auto" | "sRGB" | "linearRGB" | "inherit" | undefined;
+        colorProfile?: number | string | undefined;
+        colorRendering?: number | string | undefined;
+        contentScriptType?: number | string | undefined;
+        contentStyleType?: number | string | undefined;
+        cursor?: number | string | undefined;
+        cx?: number | string | undefined;
+        cy?: number | string | undefined;
+        d?: string | undefined;
+        decelerate?: number | string | undefined;
+        descent?: number | string | undefined;
+        diffuseConstant?: number | string | undefined;
+        direction?: number | string | undefined;
+        display?: number | string | undefined;
+        divisor?: number | string | undefined;
+        dominantBaseline?: number | string | undefined;
+        dur?: number | string | undefined;
+        dx?: number | string | undefined;
+        dy?: number | string | undefined;
+        edgeMode?: number | string | undefined;
+        elevation?: number | string | undefined;
+        enableBackground?: number | string | undefined;
+        end?: number | string | undefined;
+        exponent?: number | string | undefined;
+        externalResourcesRequired?: Booleanish | undefined;
+        fill?: string | undefined;
+        fillOpacity?: number | string | undefined;
+        fillRule?: "nonzero" | "evenodd" | "inherit" | undefined;
+        filter?: string | undefined;
+        filterRes?: number | string | undefined;
+        filterUnits?: number | string | undefined;
+        floodColor?: number | string | undefined;
+        floodOpacity?: number | string | undefined;
+        focusable?: Booleanish | "auto" | undefined;
+        fontFamily?: string | undefined;
+        fontSize?: number | string | undefined;
+        fontSizeAdjust?: number | string | undefined;
+        fontStretch?: number | string | undefined;
+        fontStyle?: number | string | undefined;
+        fontVariant?: number | string | undefined;
+        fontWeight?: number | string | undefined;
+        format?: number | string | undefined;
+        fr?: number | string | undefined;
+        from?: number | string | undefined;
+        fx?: number | string | undefined;
+        fy?: number | string | undefined;
+        g1?: number | string | undefined;
+        g2?: number | string | undefined;
+        glyphName?: number | string | undefined;
+        glyphOrientationHorizontal?: number | string | undefined;
+        glyphOrientationVertical?: number | string | undefined;
+        glyphRef?: number | string | undefined;
+        gradientTransform?: string | undefined;
+        gradientUnits?: string | undefined;
+        hanging?: number | string | undefined;
+        horizAdvX?: number | string | undefined;
+        horizOriginX?: number | string | undefined;
+        href?: string | undefined;
+        ideographic?: number | string | undefined;
+        imageRendering?: number | string | undefined;
+        in2?: number | string | undefined;
+        in?: string | undefined;
+        intercept?: number | string | undefined;
+        k1?: number | string | undefined;
+        k2?: number | string | undefined;
+        k3?: number | string | undefined;
+        k4?: number | string | undefined;
+        k?: number | string | undefined;
+        kernelMatrix?: number | string | undefined;
+        kernelUnitLength?: number | string | undefined;
+        kerning?: number | string | undefined;
+        keyPoints?: number | string | undefined;
+        keySplines?: number | string | undefined;
+        keyTimes?: number | string | undefined;
+        lengthAdjust?: number | string | undefined;
+        letterSpacing?: number | string | undefined;
+        lightingColor?: number | string | undefined;
+        limitingConeAngle?: number | string | undefined;
+        local?: number | string | undefined;
+        markerEnd?: string | undefined;
+        markerHeight?: number | string | undefined;
+        markerMid?: string | undefined;
+        markerStart?: string | undefined;
+        markerUnits?: number | string | undefined;
+        markerWidth?: number | string | undefined;
+        mask?: string | undefined;
+        maskContentUnits?: number | string | undefined;
+        maskUnits?: number | string | undefined;
+        mathematical?: number | string | undefined;
+        mode?: number | string | undefined;
+        numOctaves?: number | string | undefined;
+        offset?: number | string | undefined;
+        opacity?: number | string | undefined;
+        operator?: number | string | undefined;
+        order?: number | string | undefined;
+        orient?: number | string | undefined;
+        orientation?: number | string | undefined;
+        origin?: number | string | undefined;
+        overflow?: number | string | undefined;
+        overlinePosition?: number | string | undefined;
+        overlineThickness?: number | string | undefined;
+        paintOrder?: number | string | undefined;
+        panose1?: number | string | undefined;
+        path?: string | undefined;
+        pathLength?: number | string | undefined;
+        patternContentUnits?: string | undefined;
+        patternTransform?: number | string | undefined;
+        patternUnits?: string | undefined;
+        pointerEvents?: number | string | undefined;
+        points?: string | undefined;
+        pointsAtX?: number | string | undefined;
+        pointsAtY?: number | string | undefined;
+        pointsAtZ?: number | string | undefined;
+        preserveAlpha?: Booleanish | undefined;
+        preserveAspectRatio?: string | undefined;
+        primitiveUnits?: number | string | undefined;
+        r?: number | string | undefined;
+        radius?: number | string | undefined;
+        refX?: number | string | undefined;
+        refY?: number | string | undefined;
+        renderingIntent?: number | string | undefined;
+        repeatCount?: number | string | undefined;
+        repeatDur?: number | string | undefined;
+        requiredExtensions?: number | string | undefined;
+        requiredFeatures?: number | string | undefined;
+        restart?: number | string | undefined;
+        result?: string | undefined;
+        rotate?: number | string | undefined;
+        rx?: number | string | undefined;
+        ry?: number | string | undefined;
+        scale?: number | string | undefined;
+        seed?: number | string | undefined;
+        shapeRendering?: number | string | undefined;
+        slope?: number | string | undefined;
+        spacing?: number | string | undefined;
+        specularConstant?: number | string | undefined;
+        specularExponent?: number | string | undefined;
+        speed?: number | string | undefined;
+        spreadMethod?: string | undefined;
+        startOffset?: number | string | undefined;
+        stdDeviation?: number | string | undefined;
+        stemh?: number | string | undefined;
+        stemv?: number | string | undefined;
+        stitchTiles?: number | string | undefined;
+        stopColor?: string | undefined;
+        stopOpacity?: number | string | undefined;
+        strikethroughPosition?: number | string | undefined;
+        strikethroughThickness?: number | string | undefined;
+        string?: number | string | undefined;
+        stroke?: string | undefined;
+        strokeDasharray?: string | number | undefined;
+        strokeDashoffset?: string | number | undefined;
+        strokeLinecap?: "butt" | "round" | "square" | "inherit" | undefined;
+        strokeLinejoin?: "miter" | "round" | "bevel" | "inherit" | undefined;
+        strokeMiterlimit?: number | string | undefined;
+        strokeOpacity?: number | string | undefined;
+        strokeWidth?: number | string | undefined;
+        surfaceScale?: number | string | undefined;
+        systemLanguage?: number | string | undefined;
+        tableValues?: number | string | undefined;
+        targetX?: number | string | undefined;
+        targetY?: number | string | undefined;
+        textAnchor?: string | undefined;
+        textDecoration?: number | string | undefined;
+        textLength?: number | string | undefined;
+        textRendering?: number | string | undefined;
+        to?: number | string | undefined;
+        transform?: string | undefined;
+        u1?: number | string | undefined;
+        u2?: number | string | undefined;
+        underlinePosition?: number | string | undefined;
+        underlineThickness?: number | string | undefined;
+        unicode?: number | string | undefined;
+        unicodeBidi?: number | string | undefined;
+        unicodeRange?: number | string | undefined;
+        unitsPerEm?: number | string | undefined;
+        vAlphabetic?: number | string | undefined;
+        values?: string | undefined;
+        vectorEffect?: number | string | undefined;
+        version?: string | undefined;
+        vertAdvY?: number | string | undefined;
+        vertOriginX?: number | string | undefined;
+        vertOriginY?: number | string | undefined;
+        vHanging?: number | string | undefined;
+        vIdeographic?: number | string | undefined;
+        viewBox?: string | undefined;
+        viewTarget?: number | string | undefined;
+        visibility?: number | string | undefined;
+        vMathematical?: number | string | undefined;
+        widths?: number | string | undefined;
+        wordSpacing?: number | string | undefined;
+        writingMode?: number | string | undefined;
+        x1?: number | string | undefined;
+        x2?: number | string | undefined;
+        x?: number | string | undefined;
+        xChannelSelector?: string | undefined;
+        xHeight?: number | string | undefined;
+        xlinkActuate?: string | undefined;
+        xlinkArcrole?: string | undefined;
+        xlinkHref?: string | undefined;
+        xlinkRole?: string | undefined;
+        xlinkShow?: string | undefined;
+        xlinkTitle?: string | undefined;
+        xlinkType?: string | undefined;
+        xmlBase?: string | undefined;
+        xmlLang?: string | undefined;
+        xmlns?: string | undefined;
+        xmlnsXlink?: string | undefined;
+        xmlSpace?: string | undefined;
+        y1?: number | string | undefined;
+        y2?: number | string | undefined;
+        y?: number | string | undefined;
+        yChannelSelector?: string | undefined;
+        z?: number | string | undefined;
+        zoomAndPan?: string | undefined;
+    }
+
+    interface WebViewHTMLAttributes<T> extends HTMLAttributes<T> {
+        allowFullScreen?: boolean | undefined;
+        allowpopups?: boolean | undefined;
+        autoFocus?: boolean | undefined;
+        autosize?: boolean | undefined;
+        blinkfeatures?: string | undefined;
+        disableblinkfeatures?: string | undefined;
+        disableguestresize?: boolean | undefined;
+        disablewebsecurity?: boolean | undefined;
+        guestinstance?: string | undefined;
+        httpreferrer?: string | undefined;
+        nodeintegration?: boolean | undefined;
+        partition?: string | undefined;
+        plugins?: boolean | undefined;
+        preload?: string | undefined;
+        src?: string | undefined;
+        useragent?: string | undefined;
+        webpreferences?: string | undefined;
+    }
+
+    //
+    // React.DOM
+    // ----------------------------------------------------------------------
+
+    interface ReactHTML {
+        a: DetailedHTMLFactory<AnchorHTMLAttributes<HTMLAnchorElement>, HTMLAnchorElement>;
+        abbr: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        address: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        area: DetailedHTMLFactory<AreaHTMLAttributes<HTMLAreaElement>, HTMLAreaElement>;
+        article: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        aside: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        audio: DetailedHTMLFactory<AudioHTMLAttributes<HTMLAudioElement>, HTMLAudioElement>;
+        b: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        base: DetailedHTMLFactory<BaseHTMLAttributes<HTMLBaseElement>, HTMLBaseElement>;
+        bdi: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        bdo: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        big: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        blockquote: DetailedHTMLFactory<BlockquoteHTMLAttributes<HTMLQuoteElement>, HTMLQuoteElement>;
+        body: DetailedHTMLFactory<HTMLAttributes<HTMLBodyElement>, HTMLBodyElement>;
+        br: DetailedHTMLFactory<HTMLAttributes<HTMLBRElement>, HTMLBRElement>;
+        button: DetailedHTMLFactory<ButtonHTMLAttributes<HTMLButtonElement>, HTMLButtonElement>;
+        canvas: DetailedHTMLFactory<CanvasHTMLAttributes<HTMLCanvasElement>, HTMLCanvasElement>;
+        caption: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        cite: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        code: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        col: DetailedHTMLFactory<ColHTMLAttributes<HTMLTableColElement>, HTMLTableColElement>;
+        colgroup: DetailedHTMLFactory<ColgroupHTMLAttributes<HTMLTableColElement>, HTMLTableColElement>;
+        data: DetailedHTMLFactory<DataHTMLAttributes<HTMLDataElement>, HTMLDataElement>;
+        datalist: DetailedHTMLFactory<HTMLAttributes<HTMLDataListElement>, HTMLDataListElement>;
+        dd: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        del: DetailedHTMLFactory<DelHTMLAttributes<HTMLModElement>, HTMLModElement>;
+        details: DetailedHTMLFactory<DetailsHTMLAttributes<HTMLDetailsElement>, HTMLDetailsElement>;
+        dfn: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        dialog: DetailedHTMLFactory<DialogHTMLAttributes<HTMLDialogElement>, HTMLDialogElement>;
+        div: DetailedHTMLFactory<HTMLAttributes<HTMLDivElement>, HTMLDivElement>;
+        dl: DetailedHTMLFactory<HTMLAttributes<HTMLDListElement>, HTMLDListElement>;
+        dt: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        em: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        embed: DetailedHTMLFactory<EmbedHTMLAttributes<HTMLEmbedElement>, HTMLEmbedElement>;
+        fieldset: DetailedHTMLFactory<FieldsetHTMLAttributes<HTMLFieldSetElement>, HTMLFieldSetElement>;
+        figcaption: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        figure: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        footer: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        form: DetailedHTMLFactory<FormHTMLAttributes<HTMLFormElement>, HTMLFormElement>;
+        h1: DetailedHTMLFactory<HTMLAttributes<HTMLHeadingElement>, HTMLHeadingElement>;
+        h2: DetailedHTMLFactory<HTMLAttributes<HTMLHeadingElement>, HTMLHeadingElement>;
+        h3: DetailedHTMLFactory<HTMLAttributes<HTMLHeadingElement>, HTMLHeadingElement>;
+        h4: DetailedHTMLFactory<HTMLAttributes<HTMLHeadingElement>, HTMLHeadingElement>;
+        h5: DetailedHTMLFactory<HTMLAttributes<HTMLHeadingElement>, HTMLHeadingElement>;
+        h6: DetailedHTMLFactory<HTMLAttributes<HTMLHeadingElement>, HTMLHeadingElement>;
+        head: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLHeadElement>;
+        header: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        hgroup: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        hr: DetailedHTMLFactory<HTMLAttributes<HTMLHRElement>, HTMLHRElement>;
+        html: DetailedHTMLFactory<HtmlHTMLAttributes<HTMLHtmlElement>, HTMLHtmlElement>;
+        i: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        iframe: DetailedHTMLFactory<IframeHTMLAttributes<HTMLIFrameElement>, HTMLIFrameElement>;
+        img: DetailedHTMLFactory<ImgHTMLAttributes<HTMLImageElement>, HTMLImageElement>;
+        input: DetailedHTMLFactory<InputHTMLAttributes<HTMLInputElement>, HTMLInputElement>;
+        ins: DetailedHTMLFactory<InsHTMLAttributes<HTMLModElement>, HTMLModElement>;
+        kbd: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        keygen: DetailedHTMLFactory<KeygenHTMLAttributes<HTMLElement>, HTMLElement>;
+        label: DetailedHTMLFactory<LabelHTMLAttributes<HTMLLabelElement>, HTMLLabelElement>;
+        legend: DetailedHTMLFactory<HTMLAttributes<HTMLLegendElement>, HTMLLegendElement>;
+        li: DetailedHTMLFactory<LiHTMLAttributes<HTMLLIElement>, HTMLLIElement>;
+        link: DetailedHTMLFactory<LinkHTMLAttributes<HTMLLinkElement>, HTMLLinkElement>;
+        main: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        map: DetailedHTMLFactory<MapHTMLAttributes<HTMLMapElement>, HTMLMapElement>;
+        mark: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        menu: DetailedHTMLFactory<MenuHTMLAttributes<HTMLElement>, HTMLElement>;
+        menuitem: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        meta: DetailedHTMLFactory<MetaHTMLAttributes<HTMLMetaElement>, HTMLMetaElement>;
+        meter: DetailedHTMLFactory<MeterHTMLAttributes<HTMLMeterElement>, HTMLMeterElement>;
+        nav: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        noscript: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        object: DetailedHTMLFactory<ObjectHTMLAttributes<HTMLObjectElement>, HTMLObjectElement>;
+        ol: DetailedHTMLFactory<OlHTMLAttributes<HTMLOListElement>, HTMLOListElement>;
+        optgroup: DetailedHTMLFactory<OptgroupHTMLAttributes<HTMLOptGroupElement>, HTMLOptGroupElement>;
+        option: DetailedHTMLFactory<OptionHTMLAttributes<HTMLOptionElement>, HTMLOptionElement>;
+        output: DetailedHTMLFactory<OutputHTMLAttributes<HTMLOutputElement>, HTMLOutputElement>;
+        p: DetailedHTMLFactory<HTMLAttributes<HTMLParagraphElement>, HTMLParagraphElement>;
+        param: DetailedHTMLFactory<ParamHTMLAttributes<HTMLParamElement>, HTMLParamElement>;
+        picture: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        pre: DetailedHTMLFactory<HTMLAttributes<HTMLPreElement>, HTMLPreElement>;
+        progress: DetailedHTMLFactory<ProgressHTMLAttributes<HTMLProgressElement>, HTMLProgressElement>;
+        q: DetailedHTMLFactory<QuoteHTMLAttributes<HTMLQuoteElement>, HTMLQuoteElement>;
+        rp: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        rt: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        ruby: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        s: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        samp: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        slot: DetailedHTMLFactory<SlotHTMLAttributes<HTMLSlotElement>, HTMLSlotElement>;
+        script: DetailedHTMLFactory<ScriptHTMLAttributes<HTMLScriptElement>, HTMLScriptElement>;
+        section: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        select: DetailedHTMLFactory<SelectHTMLAttributes<HTMLSelectElement>, HTMLSelectElement>;
+        small: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        source: DetailedHTMLFactory<SourceHTMLAttributes<HTMLSourceElement>, HTMLSourceElement>;
+        span: DetailedHTMLFactory<HTMLAttributes<HTMLSpanElement>, HTMLSpanElement>;
+        strong: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        style: DetailedHTMLFactory<StyleHTMLAttributes<HTMLStyleElement>, HTMLStyleElement>;
+        sub: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        summary: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        sup: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        table: DetailedHTMLFactory<TableHTMLAttributes<HTMLTableElement>, HTMLTableElement>;
+        template: DetailedHTMLFactory<HTMLAttributes<HTMLTemplateElement>, HTMLTemplateElement>;
+        tbody: DetailedHTMLFactory<HTMLAttributes<HTMLTableSectionElement>, HTMLTableSectionElement>;
+        td: DetailedHTMLFactory<TdHTMLAttributes<HTMLTableDataCellElement>, HTMLTableDataCellElement>;
+        textarea: DetailedHTMLFactory<TextareaHTMLAttributes<HTMLTextAreaElement>, HTMLTextAreaElement>;
+        tfoot: DetailedHTMLFactory<HTMLAttributes<HTMLTableSectionElement>, HTMLTableSectionElement>;
+        th: DetailedHTMLFactory<ThHTMLAttributes<HTMLTableHeaderCellElement>, HTMLTableHeaderCellElement>;
+        thead: DetailedHTMLFactory<HTMLAttributes<HTMLTableSectionElement>, HTMLTableSectionElement>;
+        time: DetailedHTMLFactory<TimeHTMLAttributes<HTMLTimeElement>, HTMLTimeElement>;
+        title: DetailedHTMLFactory<HTMLAttributes<HTMLTitleElement>, HTMLTitleElement>;
+        tr: DetailedHTMLFactory<HTMLAttributes<HTMLTableRowElement>, HTMLTableRowElement>;
+        track: DetailedHTMLFactory<TrackHTMLAttributes<HTMLTrackElement>, HTMLTrackElement>;
+        u: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        ul: DetailedHTMLFactory<HTMLAttributes<HTMLUListElement>, HTMLUListElement>;
+        "var": DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        video: DetailedHTMLFactory<VideoHTMLAttributes<HTMLVideoElement>, HTMLVideoElement>;
+        wbr: DetailedHTMLFactory<HTMLAttributes<HTMLElement>, HTMLElement>;
+        webview: DetailedHTMLFactory<WebViewHTMLAttributes<HTMLWebViewElement>, HTMLWebViewElement>;
+    }
+
+    interface ReactSVG {
+        animate: SVGFactory;
+        circle: SVGFactory;
+        clipPath: SVGFactory;
+        defs: SVGFactory;
+        desc: SVGFactory;
+        ellipse: SVGFactory;
+        feBlend: SVGFactory;
+        feColorMatrix: SVGFactory;
+        feComponentTransfer: SVGFactory;
+        feComposite: SVGFactory;
+        feConvolveMatrix: SVGFactory;
+        feDiffuseLighting: SVGFactory;
+        feDisplacementMap: SVGFactory;
+        feDistantLight: SVGFactory;
+        feDropShadow: SVGFactory;
+        feFlood: SVGFactory;
+        feFuncA: SVGFactory;
+        feFuncB: SVGFactory;
+        feFuncG: SVGFactory;
+        feFuncR: SVGFactory;
+        feGaussianBlur: SVGFactory;
+        feImage: SVGFactory;
+        feMerge: SVGFactory;
+        feMergeNode: SVGFactory;
+        feMorphology: SVGFactory;
+        feOffset: SVGFactory;
+        fePointLight: SVGFactory;
+        feSpecularLighting: SVGFactory;
+        feSpotLight: SVGFactory;
+        feTile: SVGFactory;
+        feTurbulence: SVGFactory;
+        filter: SVGFactory;
+        foreignObject: SVGFactory;
+        g: SVGFactory;
+        image: SVGFactory;
+        line: SVGFactory;
+        linearGradient: SVGFactory;
+        marker: SVGFactory;
+        mask: SVGFactory;
+        metadata: SVGFactory;
+        path: SVGFactory;
+        pattern: SVGFactory;
+        polygon: SVGFactory;
+        polyline: SVGFactory;
+        radialGradient: SVGFactory;
+        rect: SVGFactory;
+        stop: SVGFactory;
+        svg: SVGFactory;
+        switch: SVGFactory;
+        symbol: SVGFactory;
+        text: SVGFactory;
+        textPath: SVGFactory;
+        tspan: SVGFactory;
+        use: SVGFactory;
+        view: SVGFactory;
+    }
+
+    interface ReactDOM extends ReactHTML, ReactSVG { }
+
+    //
+    // React.PropTypes
+    // ----------------------------------------------------------------------
+
+    type Validator<T> = PropTypes.Validator<T>;
+
+    type Requireable<T> = PropTypes.Requireable<T>;
+
+    type ValidationMap<T> = PropTypes.ValidationMap<T>;
+
+    type WeakValidationMap<T> = {
+        [K in keyof T]?: null extends T[K]
+            ? Validator<T[K] | null | undefined>
+            : undefined extends T[K]
+            ? Validator<T[K] | null | undefined>
+            : Validator<T[K]>
+    };
+
+    interface ReactPropTypes {
+        any: typeof PropTypes.any;
+        array: typeof PropTypes.array;
+        bool: typeof PropTypes.bool;
+        func: typeof PropTypes.func;
+        number: typeof PropTypes.number;
+        object: typeof PropTypes.object;
+        string: typeof PropTypes.string;
+        node: typeof PropTypes.node;
+        element: typeof PropTypes.element;
+        instanceOf: typeof PropTypes.instanceOf;
+        oneOf: typeof PropTypes.oneOf;
+        oneOfType: typeof PropTypes.oneOfType;
+        arrayOf: typeof PropTypes.arrayOf;
+        objectOf: typeof PropTypes.objectOf;
+        shape: typeof PropTypes.shape;
+        exact: typeof PropTypes.exact;
+    }
+
+    //
+    // React.Children
+    // ----------------------------------------------------------------------
+
+    interface ReactChildren {
+        map<T, C>(children: C | ReadonlyArray<C>, fn: (child: C, index: number) => T):
+            C extends null | undefined ? C : Array<Exclude<T, boolean | null | undefined>>;
+        forEach<C>(children: C | ReadonlyArray<C>, fn: (child: C, index: number) => void): void;
+        count(children: any): number;
+        only<C>(children: C): C extends any[] ? never : C;
+        toArray(children: ReactNode | ReactNode[]): Array<Exclude<ReactNode, boolean | null | undefined>>;
+    }
+
+    //
+    // Browser Interfaces
+    // https://github.com/nikeee/2048-typescript/blob/master/2048/js/touch.d.ts
+    // ----------------------------------------------------------------------
+
+    interface AbstractView {
+        styleMedia: StyleMedia;
+        document: Document;
+    }
+
+    interface Touch {
+        identifier: number;
+        target: EventTarget;
+        screenX: number;
+        screenY: number;
+        clientX: number;
+        clientY: number;
+        pageX: number;
+        pageY: number;
+    }
+
+    interface TouchList {
+        [index: number]: Touch;
+        length: number;
+        item(index: number): Touch;
+        identifiedTouch(identifier: number): Touch;
+    }
+
+    //
+    // Error Interfaces
+    // ----------------------------------------------------------------------
+    interface ErrorInfo {
+        /**
+         * Captures which component contained the exception, and its ancestors.
+         */
+        componentStack: string;
+    }
+}
+
+// naked 'any' type in a conditional type will short circuit and union both the then/else branches
+// so boolean is only resolved for T = any
+type IsExactlyAny<T> = boolean extends (T extends never ? true : false) ? true : false;
+
+type ExactlyAnyPropertyKeys<T> = { [K in keyof T]: IsExactlyAny<T[K]> extends true ? K : never }[keyof T];
+type NotExactlyAnyPropertyKeys<T> = Exclude<keyof T, ExactlyAnyPropertyKeys<T>>;
+
+// Try to resolve ill-defined props like for JS users: props can be any, or sometimes objects with properties of type any
+type MergePropTypes<P, T> =
+    // Distribute over P in case it is a union type
+    P extends any
+        // If props is type any, use propTypes definitions
+        ? IsExactlyAny<P> extends true ? T :
+            // If declared props have indexed properties, ignore inferred props entirely as keyof gets widened
+            string extends keyof P ? P :
+                // Prefer declared types which are not exactly any
+                & Pick<P, NotExactlyAnyPropertyKeys<P>>
+                // For props which are exactly any, use the type inferred from propTypes if present
+                & Pick<T, Exclude<keyof T, NotExactlyAnyPropertyKeys<P>>>
+                // Keep leftover props not specified in propTypes
+                & Pick<P, Exclude<keyof P, keyof T>>
+        : never;
+
+// Any prop that has a default prop becomes optional, but its type is unchanged
+// Undeclared default props are augmented into the resulting allowable attributes
+// If declared props have indexed properties, ignore default props entirely as keyof gets widened
+// Wrap in an outer-level conditional type to allow distribution over props that are unions
+type Defaultize<P, D> = P extends any
+    ? string extends keyof P ? P :
+        & Pick<P, Exclude<keyof P, keyof D>>
+        & Partial<Pick<P, Extract<keyof P, keyof D>>>
+        & Partial<Pick<D, Exclude<keyof D, keyof P>>>
+    : never;
+
+type ReactManagedAttributes<C, P> = C extends { propTypes: infer T; defaultProps: infer D; }
+    ? Defaultize<MergePropTypes<P, PropTypes.InferProps<T>>, D>
+    : C extends { propTypes: infer T; }
+        ? MergePropTypes<P, PropTypes.InferProps<T>>
+        : C extends { defaultProps: infer D; }
+            ? Defaultize<P, D>
+            : P;
+
+declare global {
+    namespace JSX {
+        interface Element extends React.ReactElement<any, any> { }
+        interface ElementClass extends React.Component<any> {
+            render(): React.ReactNode;
+        }
+        interface ElementAttributesProperty { props: {}; }
+        interface ElementChildrenAttribute { children: {}; }
+
+        // We can't recurse forever because `type` can't be self-referential;
+        // let's assume it's reasonable to do a single React.lazy() around a single React.memo() / vice-versa
+        type LibraryManagedAttributes<C, P> = C extends React.MemoExoticComponent<infer T> | React.LazyExoticComponent<infer T>
+            ? T extends React.MemoExoticComponent<infer U> | React.LazyExoticComponent<infer U>
+                ? ReactManagedAttributes<U, P>
+                : ReactManagedAttributes<T, P>
+            : ReactManagedAttributes<C, P>;
+
+        interface IntrinsicAttributes extends React.Attributes { }
+        interface IntrinsicClassAttributes<T> extends React.ClassAttributes<T> { }
+
+        interface IntrinsicElements {
+            // HTML
+            a: React.DetailedHTMLProps<React.AnchorHTMLAttributes<HTMLAnchorElement>, HTMLAnchorElement>;
+            abbr: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            address: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            area: React.DetailedHTMLProps<React.AreaHTMLAttributes<HTMLAreaElement>, HTMLAreaElement>;
+            article: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            aside: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            audio: React.DetailedHTMLProps<React.AudioHTMLAttributes<HTMLAudioElement>, HTMLAudioElement>;
+            b: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            base: React.DetailedHTMLProps<React.BaseHTMLAttributes<HTMLBaseElement>, HTMLBaseElement>;
+            bdi: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            bdo: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            big: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            blockquote: React.DetailedHTMLProps<React.BlockquoteHTMLAttributes<HTMLQuoteElement>, HTMLQuoteElement>;
+            body: React.DetailedHTMLProps<React.HTMLAttributes<HTMLBodyElement>, HTMLBodyElement>;
+            br: React.DetailedHTMLProps<React.HTMLAttributes<HTMLBRElement>, HTMLBRElement>;
+            button: React.DetailedHTMLProps<React.ButtonHTMLAttributes<HTMLButtonElement>, HTMLButtonElement>;
+            canvas: React.DetailedHTMLProps<React.CanvasHTMLAttributes<HTMLCanvasElement>, HTMLCanvasElement>;
+            caption: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            cite: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            code: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            col: React.DetailedHTMLProps<React.ColHTMLAttributes<HTMLTableColElement>, HTMLTableColElement>;
+            colgroup: React.DetailedHTMLProps<React.ColgroupHTMLAttributes<HTMLTableColElement>, HTMLTableColElement>;
+            data: React.DetailedHTMLProps<React.DataHTMLAttributes<HTMLDataElement>, HTMLDataElement>;
+            datalist: React.DetailedHTMLProps<React.HTMLAttributes<HTMLDataListElement>, HTMLDataListElement>;
+            dd: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            del: React.DetailedHTMLProps<React.DelHTMLAttributes<HTMLModElement>, HTMLModElement>;
+            details: React.DetailedHTMLProps<React.DetailsHTMLAttributes<HTMLDetailsElement>, HTMLDetailsElement>;
+            dfn: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            dialog: React.DetailedHTMLProps<React.DialogHTMLAttributes<HTMLDialogElement>, HTMLDialogElement>;
+            div: React.DetailedHTMLProps<React.HTMLAttributes<HTMLDivElement>, HTMLDivElement>;
+            dl: React.DetailedHTMLProps<React.HTMLAttributes<HTMLDListElement>, HTMLDListElement>;
+            dt: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            em: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            embed: React.DetailedHTMLProps<React.EmbedHTMLAttributes<HTMLEmbedElement>, HTMLEmbedElement>;
+            fieldset: React.DetailedHTMLProps<React.FieldsetHTMLAttributes<HTMLFieldSetElement>, HTMLFieldSetElement>;
+            figcaption: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            figure: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            footer: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            form: React.DetailedHTMLProps<React.FormHTMLAttributes<HTMLFormElement>, HTMLFormElement>;
+            h1: React.DetailedHTMLProps<React.HTMLAttributes<HTMLHeadingElement>, HTMLHeadingElement>;
+            h2: React.DetailedHTMLProps<React.HTMLAttributes<HTMLHeadingElement>, HTMLHeadingElement>;
+            h3: React.DetailedHTMLProps<React.HTMLAttributes<HTMLHeadingElement>, HTMLHeadingElement>;
+            h4: React.DetailedHTMLProps<React.HTMLAttributes<HTMLHeadingElement>, HTMLHeadingElement>;
+            h5: React.DetailedHTMLProps<React.HTMLAttributes<HTMLHeadingElement>, HTMLHeadingElement>;
+            h6: React.DetailedHTMLProps<React.HTMLAttributes<HTMLHeadingElement>, HTMLHeadingElement>;
+            head: React.DetailedHTMLProps<React.HTMLAttributes<HTMLHeadElement>, HTMLHeadElement>;
+            header: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            hgroup: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            hr: React.DetailedHTMLProps<React.HTMLAttributes<HTMLHRElement>, HTMLHRElement>;
+            html: React.DetailedHTMLProps<React.HtmlHTMLAttributes<HTMLHtmlElement>, HTMLHtmlElement>;
+            i: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            iframe: React.DetailedHTMLProps<React.IframeHTMLAttributes<HTMLIFrameElement>, HTMLIFrameElement>;
+            img: React.DetailedHTMLProps<React.ImgHTMLAttributes<HTMLImageElement>, HTMLImageElement>;
+            input: React.DetailedHTMLProps<React.InputHTMLAttributes<HTMLInputElement>, HTMLInputElement>;
+            ins: React.DetailedHTMLProps<React.InsHTMLAttributes<HTMLModElement>, HTMLModElement>;
+            kbd: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            keygen: React.DetailedHTMLProps<React.KeygenHTMLAttributes<HTMLElement>, HTMLElement>;
+            label: React.DetailedHTMLProps<React.LabelHTMLAttributes<HTMLLabelElement>, HTMLLabelElement>;
+            legend: React.DetailedHTMLProps<React.HTMLAttributes<HTMLLegendElement>, HTMLLegendElement>;
+            li: React.DetailedHTMLProps<React.LiHTMLAttributes<HTMLLIElement>, HTMLLIElement>;
+            link: React.DetailedHTMLProps<React.LinkHTMLAttributes<HTMLLinkElement>, HTMLLinkElement>;
+            main: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            map: React.DetailedHTMLProps<React.MapHTMLAttributes<HTMLMapElement>, HTMLMapElement>;
+            mark: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            menu: React.DetailedHTMLProps<React.MenuHTMLAttributes<HTMLElement>, HTMLElement>;
+            menuitem: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            meta: React.DetailedHTMLProps<React.MetaHTMLAttributes<HTMLMetaElement>, HTMLMetaElement>;
+            meter: React.DetailedHTMLProps<React.MeterHTMLAttributes<HTMLMeterElement>, HTMLMeterElement>;
+            nav: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            noindex: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            noscript: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            object: React.DetailedHTMLProps<React.ObjectHTMLAttributes<HTMLObjectElement>, HTMLObjectElement>;
+            ol: React.DetailedHTMLProps<React.OlHTMLAttributes<HTMLOListElement>, HTMLOListElement>;
+            optgroup: React.DetailedHTMLProps<React.OptgroupHTMLAttributes<HTMLOptGroupElement>, HTMLOptGroupElement>;
+            option: React.DetailedHTMLProps<React.OptionHTMLAttributes<HTMLOptionElement>, HTMLOptionElement>;
+            output: React.DetailedHTMLProps<React.OutputHTMLAttributes<HTMLOutputElement>, HTMLOutputElement>;
+            p: React.DetailedHTMLProps<React.HTMLAttributes<HTMLParagraphElement>, HTMLParagraphElement>;
+            param: React.DetailedHTMLProps<React.ParamHTMLAttributes<HTMLParamElement>, HTMLParamElement>;
+            picture: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            pre: React.DetailedHTMLProps<React.HTMLAttributes<HTMLPreElement>, HTMLPreElement>;
+            progress: React.DetailedHTMLProps<React.ProgressHTMLAttributes<HTMLProgressElement>, HTMLProgressElement>;
+            q: React.DetailedHTMLProps<React.QuoteHTMLAttributes<HTMLQuoteElement>, HTMLQuoteElement>;
+            rp: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            rt: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            ruby: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            s: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            samp: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            slot: React.DetailedHTMLProps<React.SlotHTMLAttributes<HTMLSlotElement>, HTMLSlotElement>;
+            script: React.DetailedHTMLProps<React.ScriptHTMLAttributes<HTMLScriptElement>, HTMLScriptElement>;
+            section: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            select: React.DetailedHTMLProps<React.SelectHTMLAttributes<HTMLSelectElement>, HTMLSelectElement>;
+            small: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            source: React.DetailedHTMLProps<React.SourceHTMLAttributes<HTMLSourceElement>, HTMLSourceElement>;
+            span: React.DetailedHTMLProps<React.HTMLAttributes<HTMLSpanElement>, HTMLSpanElement>;
+            strong: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            style: React.DetailedHTMLProps<React.StyleHTMLAttributes<HTMLStyleElement>, HTMLStyleElement>;
+            sub: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            summary: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            sup: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            table: React.DetailedHTMLProps<React.TableHTMLAttributes<HTMLTableElement>, HTMLTableElement>;
+            template: React.DetailedHTMLProps<React.HTMLAttributes<HTMLTemplateElement>, HTMLTemplateElement>;
+            tbody: React.DetailedHTMLProps<React.HTMLAttributes<HTMLTableSectionElement>, HTMLTableSectionElement>;
+            td: React.DetailedHTMLProps<React.TdHTMLAttributes<HTMLTableDataCellElement>, HTMLTableDataCellElement>;
+            textarea: React.DetailedHTMLProps<React.TextareaHTMLAttributes<HTMLTextAreaElement>, HTMLTextAreaElement>;
+            tfoot: React.DetailedHTMLProps<React.HTMLAttributes<HTMLTableSectionElement>, HTMLTableSectionElement>;
+            th: React.DetailedHTMLProps<React.ThHTMLAttributes<HTMLTableHeaderCellElement>, HTMLTableHeaderCellElement>;
+            thead: React.DetailedHTMLProps<React.HTMLAttributes<HTMLTableSectionElement>, HTMLTableSectionElement>;
+            time: React.DetailedHTMLProps<React.TimeHTMLAttributes<HTMLTimeElement>, HTMLTimeElement>;
+            title: React.DetailedHTMLProps<React.HTMLAttributes<HTMLTitleElement>, HTMLTitleElement>;
+            tr: React.DetailedHTMLProps<React.HTMLAttributes<HTMLTableRowElement>, HTMLTableRowElement>;
+            track: React.DetailedHTMLProps<React.TrackHTMLAttributes<HTMLTrackElement>, HTMLTrackElement>;
+            u: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            ul: React.DetailedHTMLProps<React.HTMLAttributes<HTMLUListElement>, HTMLUListElement>;
+            "var": React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            video: React.DetailedHTMLProps<React.VideoHTMLAttributes<HTMLVideoElement>, HTMLVideoElement>;
+            wbr: React.DetailedHTMLProps<React.HTMLAttributes<HTMLElement>, HTMLElement>;
+            webview: React.DetailedHTMLProps<React.WebViewHTMLAttributes<HTMLWebViewElement>, HTMLWebViewElement>;
+
+            // SVG
+            svg: React.SVGProps<SVGSVGElement>;
+
+            animate: React.SVGProps<SVGElement>; // TODO: It is SVGAnimateElement but is not in TypeScript's lib.dom.d.ts for now.
+            animateMotion: React.SVGProps<SVGElement>;
+            animateTransform: React.SVGProps<SVGElement>; // TODO: It is SVGAnimateTransformElement but is not in TypeScript's lib.dom.d.ts for now.
+            circle: React.SVGProps<SVGCircleElement>;
+            clipPath: React.SVGProps<SVGClipPathElement>;
+            defs: React.SVGProps<SVGDefsElement>;
+            desc: React.SVGProps<SVGDescElement>;
+            ellipse: React.SVGProps<SVGEllipseElement>;
+            feBlend: React.SVGProps<SVGFEBlendElement>;
+            feColorMatrix: React.SVGProps<SVGFEColorMatrixElement>;
+            feComponentTransfer: React.SVGProps<SVGFEComponentTransferElement>;
+            feComposite: React.SVGProps<SVGFECompositeElement>;
+            feConvolveMatrix: React.SVGProps<SVGFEConvolveMatrixElement>;
+            feDiffuseLighting: React.SVGProps<SVGFEDiffuseLightingElement>;
+            feDisplacementMap: React.SVGProps<SVGFEDisplacementMapElement>;
+            feDistantLight: React.SVGProps<SVGFEDistantLightElement>;
+            feDropShadow: React.SVGProps<SVGFEDropShadowElement>;
+            feFlood: React.SVGProps<SVGFEFloodElement>;
+            feFuncA: React.SVGProps<SVGFEFuncAElement>;
+            feFuncB: React.SVGProps<SVGFEFuncBElement>;
+            feFuncG: React.SVGProps<SVGFEFuncGElement>;
+            feFuncR: React.SVGProps<SVGFEFuncRElement>;
+            feGaussianBlur: React.SVGProps<SVGFEGaussianBlurElement>;
+            feImage: React.SVGProps<SVGFEImageElement>;
+            feMerge: React.SVGProps<SVGFEMergeElement>;
+            feMergeNode: React.SVGProps<SVGFEMergeNodeElement>;
+            feMorphology: React.SVGProps<SVGFEMorphologyElement>;
+            feOffset: React.SVGProps<SVGFEOffsetElement>;
+            fePointLight: React.SVGProps<SVGFEPointLightElement>;
+            feSpecularLighting: React.SVGProps<SVGFESpecularLightingElement>;
+            feSpotLight: React.SVGProps<SVGFESpotLightElement>;
+            feTile: React.SVGProps<SVGFETileElement>;
+            feTurbulence: React.SVGProps<SVGFETurbulenceElement>;
+            filter: React.SVGProps<SVGFilterElement>;
+            foreignObject: React.SVGProps<SVGForeignObjectElement>;
+            g: React.SVGProps<SVGGElement>;
+            image: React.SVGProps<SVGImageElement>;
+            line: React.SVGProps<SVGLineElement>;
+            linearGradient: React.SVGProps<SVGLinearGradientElement>;
+            marker: React.SVGProps<SVGMarkerElement>;
+            mask: React.SVGProps<SVGMaskElement>;
+            metadata: React.SVGProps<SVGMetadataElement>;
+            mpath: React.SVGProps<SVGElement>;
+            path: React.SVGProps<SVGPathElement>;
+            pattern: React.SVGProps<SVGPatternElement>;
+            polygon: React.SVGProps<SVGPolygonElement>;
+            polyline: React.SVGProps<SVGPolylineElement>;
+            radialGradient: React.SVGProps<SVGRadialGradientElement>;
+            rect: React.SVGProps<SVGRectElement>;
+            stop: React.SVGProps<SVGStopElement>;
+            switch: React.SVGProps<SVGSwitchElement>;
+            symbol: React.SVGProps<SVGSymbolElement>;
+            text: React.SVGProps<SVGTextElement>;
+            textPath: React.SVGProps<SVGTextPathElement>;
+            tspan: React.SVGProps<SVGTSpanElement>;
+            use: React.SVGProps<SVGUseElement>;
+            view: React.SVGProps<SVGViewElement>;
+        }
+    }
+}
diff --git a/types/react/v17/jsx-dev-runtime.d.ts b/types/react/v17/jsx-dev-runtime.d.ts
new file mode 100644
index 00000000000000..c7bb3e90508473
--- /dev/null
+++ b/types/react/v17/jsx-dev-runtime.d.ts
@@ -0,0 +1,2 @@
+// Expose `JSX` namespace in `global` namespace
+import './';
diff --git a/types/react/v17/jsx-runtime.d.ts b/types/react/v17/jsx-runtime.d.ts
new file mode 100644
index 00000000000000..c7bb3e90508473
--- /dev/null
+++ b/types/react/v17/jsx-runtime.d.ts
@@ -0,0 +1,2 @@
+// Expose `JSX` namespace in `global` namespace
+import './';
diff --git a/types/react/v17/package.json b/types/react/v17/package.json
new file mode 100644
index 00000000000000..9bda6d414c39bf
--- /dev/null
+++ b/types/react/v17/package.json
@@ -0,0 +1,6 @@
+{
+  "private": true,
+  "dependencies": {
+    "csstype": "^3.0.2"
+  }
+}
diff --git a/types/react/v17/test/cssProperties.tsx b/types/react/v17/test/cssProperties.tsx
new file mode 100644
index 00000000000000..4ef8ab792a959f
--- /dev/null
+++ b/types/react/v17/test/cssProperties.tsx
@@ -0,0 +1,48 @@
+import * as React from 'react';
+
+const initialStyle: React.CSSProperties = { fontWeight: 'initial' };
+const initialStyleTest = <div style={initialStyle} />;
+
+const borderRadiusStyle: React.CSSProperties = { borderRadius: 5, borderTopRightRadius: '20%' };
+const borderRadiusStyleTest = <div style={borderRadiusStyle} />;
+
+const backgroundAttachmentStyle: React.CSSProperties = { backgroundAttachment: 'fixed' };
+const backgroundAttachmentStyleTest = <div style={backgroundAttachmentStyle} />;
+
+const columnCountStyle: React.CSSProperties = { columnCount: 'auto' };
+const columnCountStyleTest = <div style={columnCountStyle} />;
+
+const fontSizeAdjustStyle: React.CSSProperties = { fontSizeAdjust: 'none' };
+const fontSizeAdjustStyleTest = <div style={fontSizeAdjustStyle} />;
+
+const fontStretchStyle: React.CSSProperties = { fontStretch: 'condensed' };
+const fontStretchStyleTest = <div style={fontStretchStyle} />;
+
+const fontStyleStyle: React.CSSProperties = { fontStyle: 'italic' };
+const fontStyleStyleTest = <div style={fontStyleStyle} />;
+
+const fontWeightStyle: React.CSSProperties = { fontWeight: 400 };
+const fontWeightStyleTest = <div style={fontWeightStyle} />;
+
+const justifyContentStyle: React.CSSProperties = { justifyContent: 'space-evenly' };
+const justifyContentStyleTest = <div style={justifyContentStyle} />;
+
+const boxShadowStyle: React.CSSProperties = { boxShadow: '2px 2px 2px 1px rgba(0, 0, 0, 0.2)' };
+const boxShadowStyleTest = <div style={boxShadowStyle} />;
+
+const overflowStyle: React.CSSProperties = { overflow: 'auto', overflowX: 'visible', overflowY: 'scroll' };
+const overflowStyleTest = <div style={overflowStyle} />;
+
+const positionStyle: React.CSSProperties = { position: 'relative' };
+const positionStyleTest = <div style={positionStyle} />;
+
+// SVG specific style attribute declarations
+
+const fillOpacityStyle: React.CSSProperties = { fillOpacity: 0.3 };
+const fillOpacityStyleTest = <svg style={fillOpacityStyle} />;
+
+const strokeOpacityStyle: React.CSSProperties = { strokeOpacity: 0.3 };
+const strokeOpacityStyleTest = <svg style={strokeOpacityStyle} />;
+
+const strokeWidthStyle: React.CSSProperties = { strokeWidth: '10px' };
+const strokeWidthStyleTest = <svg style={strokeWidthStyle} />;
diff --git a/types/react/v17/test/elementAttributes.tsx b/types/react/v17/test/elementAttributes.tsx
new file mode 100644
index 00000000000000..db6909d63e0b17
--- /dev/null
+++ b/types/react/v17/test/elementAttributes.tsx
@@ -0,0 +1,98 @@
+import * as React from 'react';
+
+const testCases = [
+    <span />,
+    <span accessKey="s" />,
+    <span className="klass" />,
+    <span contentEditable />,
+    <span contextMenu="menuId" />,
+    <span dir="rtl" />,
+    <span draggable />,
+    <span hidden />,
+    <span id="s" />,
+    <span lang="art-x-tokipona" />,
+    <input placeholder="placeholder" />,
+    <span slot="my-text" />,
+    <span spellCheck />,
+    <span tabIndex={0} />,
+    <span title="title" />,
+    <span role="button" />,
+    <span autoCapitalize="off" />,
+    <span autoCapitalize="none" />,
+    <span autoCapitalize="on" />,
+    <span autoCapitalize="words" />,
+    <span autoCapitalize="sentences" />,
+    <span autoCorrect="off" />,
+    <span autoCorrect="on" />,
+    <span translate="no" />,
+    <span translate="yes" />,
+    <svg>
+        <image crossOrigin="anonymous" />
+    </svg>,
+    <details open={true} onToggle={() => {}} />,
+    <input value={['one', 'two'] as ReadonlyArray<string>} />,
+    <input value={['one', 'two'] as string[]} />,
+    <input value={['one', 'two']} />,
+    <input enterKeyHint="done" />,
+    <input accept="image/*" capture="user" />,
+    <input accept="image/*" capture="environment" />,
+    <input accept="image/*" capture />,
+    <input accept="video/*" capture="user" />,
+    <input accept="video/*" capture="environment" />,
+    // $ExpectError
+    <input accept="video/*" capture="haha" />,
+    <input accept="video/*" capture />,
+    <input accept="audio/*" capture />,
+
+    <div role="dialog" />,
+    <div role="none presentation" />,
+    <svg role="treeitem" />,
+    <a target="_blank"></a>,
+    <a target="some-frame"></a>,
+    <input type="button" />,
+    <input type="some-type" />,
+    // $ExpectError
+    <input enterKeyHint="don" />,
+    <video disableRemotePlayback />,
+    <picture>
+        <source media="test" srcSet="test" width={50} height={50} />
+        <img src="test" width={100} height={100} />
+    </picture>,
+];
+
+// Needed to check these HTML elements in event callbacks.
+// "Imported" from typescript's lib.dom.d.ts.
+declare global {
+    interface HTMLDetailsElement {
+        open: boolean;
+    }
+
+    interface HTMLMeterElement {
+        optimum: number;
+    }
+
+    interface HTMLModElement {
+        cite: string;
+    }
+
+    interface HTMLOutputElement {
+        value: string;
+    }
+
+    interface HTMLQuoteElement {
+        cite: string;
+    }
+
+    interface HTMLTimeElement {
+        dateTime: string;
+    }
+}
+
+const eventCallbacksTestCases = [
+    <blockquote onClick={e => e.currentTarget.cite} />,
+    <del onClick={e => e.currentTarget.cite} />,
+    <details onClick={e => e.currentTarget.open} />,
+    <meter onClick={e => e.currentTarget.optimum} />,
+    <output onClick={e => e.currentTarget.value} />,
+    <time onClick={e => e.currentTarget.dateTime} />,
+];
diff --git a/types/react/v17/test/hooks.tsx b/types/react/v17/test/hooks.tsx
new file mode 100644
index 00000000000000..88c32eb34d3f8e
--- /dev/null
+++ b/types/react/v17/test/hooks.tsx
@@ -0,0 +1,254 @@
+import * as React from "react";
+
+interface PersonProps {
+    name: string;
+    age: number;
+}
+export function Person(props: PersonProps) {
+    return <div>
+        hello! I'm {props.name} and I'm {props.age} years old!
+    </div>;
+}
+
+export interface FancyButtonProps {
+    onClick: () => void;
+    children?: React.ReactNode | undefined;
+}
+export interface FancyButtonMethod {
+    fancyClick(): void;
+}
+export const FancyButton = React.forwardRef((props: FancyButtonProps, ref: React.Ref<FancyButtonMethod>) => {
+    const buttonRef = React.useRef<HTMLButtonElement | null>(null);
+    const [count, setCount] = React.useState(0);
+
+    React.useImperativeHandle(ref, () => ({
+        fancyClick() {
+            buttonRef.current!; // $ExpectType HTMLButtonElement
+        },
+        getClickCount() {
+            return count;
+        }
+    }));
+
+    return <button onClick={() => { setCount(count + 1); props.onClick(); }}>
+        {props.children}
+    </button>;
+});
+
+interface AppState {
+    name: string;
+    age: number;
+}
+
+type AppActions =
+    | { type: "getOlder" }
+    | { type: "resetAge" };
+
+function reducer(s: AppState, action: AppActions): AppState {
+    switch (action.type) {
+        case "getOlder":
+            return { ...s, age: s.age + 1 };
+        case "resetAge":
+            return { ...s, age: 0 };
+    }
+}
+
+const initialState = {
+    name: "Daniel",
+    age: 26
+};
+
+export function App() {
+    const [state, dispatch] = React.useReducer(reducer, initialState);
+    const birthdayRef = React.useRef<React.ComponentRef<typeof FancyButton>>(null);
+
+    React.useLayoutEffect(() => {
+        if (birthdayRef.current !== null) {
+            birthdayRef.current.fancyClick();
+        } else {
+            // this looks redundant but it ensures the type actually has "null" in it instead of "never"
+            // $ExpectType null
+            birthdayRef.current;
+        }
+    });
+
+    return <>
+        <Person {...state} />
+        <FancyButton onClick={() => dispatch({ type: "getOlder" })}>
+            Birthday time!
+        </FancyButton>
+        <FancyButton onClick={() => dispatch({ type: "resetAge" })}>
+            Let's start over.
+        </FancyButton>
+    </>;
+}
+
+interface Context {
+    test: true;
+}
+const context = React.createContext<Context>({ test: true });
+
+function useEveryHook(ref: React.Ref<{ id: number }>|undefined): () => boolean {
+    const value: Context = React.useContext(context);
+    const [, setState] = React.useState(() => 0);
+    // Bonus typescript@next version
+    // const [reducerState, dispatch] = React.useReducer(reducer, true as const, arg => arg && initialState);
+    // Compile error in typescript@3.0 but not in typescript@3.1.
+    // const [reducerState, dispatch] = React.useReducer(reducer, true as true, arg => arg && initialState);
+    const [reducerState, dispatch] = React.useReducer(reducer, true as true, (arg: true): AppState => arg && initialState);
+
+    const [, simpleDispatch] = React.useReducer(v => v + 1, 0);
+
+    // inline object, to (manually) check if autocomplete works
+    React.useReducer(reducer, { age: 42, name: 'The Answer' });
+
+    // Implicit any
+    // $ExpectError
+    const anyCallback = React.useCallback(value => {
+        // $ExpectType any
+        return value;
+    }, []);
+    // $ExpectType any
+    anyCallback({});
+    // $ExpectType (value: string) => number
+    const typedCallback = React.useCallback((value: string) => {
+        return Number(value);
+    }, []);
+    // $ExpectType number
+    typedCallback("1");
+    // Argument of type '{}' is not assignable to parameter of type 'string'.
+    // $ExpectError
+    typedCallback({});
+
+    // test useRef and its convenience overloads
+    // $ExpectType MutableRefObject<number>
+    React.useRef(0);
+
+    // these are not very useful (can't assign anything else to .current)
+    // but it's the only safe way to resolve them
+    // $ExpectType MutableRefObject<null>
+    React.useRef(null);
+    // $ExpectType MutableRefObject<undefined>
+    React.useRef(undefined);
+
+    // |null convenience overload
+    // it should _not_ be mutable if the generic argument doesn't include null
+    // $ExpectType RefObject<number>
+    React.useRef<number>(null);
+    // but it should be mutable if it does (i.e. is not the convenience overload)
+    // $ExpectType MutableRefObject<number | null>
+    React.useRef<number | null>(null);
+
+    // |undefined convenience overload
+    // with no contextual type or generic argument it should default to undefined only (not {} or unknown!)
+    // $ExpectType MutableRefObject<undefined>
+    React.useRef();
+    // $ExpectType MutableRefObject<number | undefined>
+    React.useRef<number>();
+    // don't just accept a potential undefined if there is a generic argument
+    // $ExpectError
+    React.useRef<number>(undefined);
+    // make sure once again there's no |undefined if the initial value doesn't either
+    // $ExpectType MutableRefObject<number>
+    React.useRef<number>(1);
+    // and also that it is not getting erased if the parameter is wider
+    // $ExpectType MutableRefObject<number | undefined>
+    React.useRef<number | undefined>(1);
+
+    // should be contextually typed
+    const a: React.MutableRefObject<number | undefined> = React.useRef(undefined);
+    const b: React.MutableRefObject<number | undefined> = React.useRef();
+    const c: React.MutableRefObject<number | null> = React.useRef(null);
+    const d: React.RefObject<number> = React.useRef(null);
+
+    const id = React.useMemo(() => Math.random(), []);
+    React.useImperativeHandle(ref, () => ({ id }), [id]);
+    // was named like this in the first alpha, renamed before release
+    // $ExpectError
+    React.useImperativeMethods(ref, () => ({}), [id]);
+
+    // make sure again this is not going to the |null convenience overload
+    // $ExpectType MutableRefObject<boolean>
+    const didLayout = React.useRef(false);
+
+    React.useLayoutEffect(() => {
+        setState(1);
+        setState(prevState => prevState - 1);
+        didLayout.current = true;
+    }, []);
+    React.useEffect(() => {
+        dispatch({ type: 'getOlder' });
+        // $ExpectError
+        dispatch();
+
+        simpleDispatch();
+        setState(reducerState.age);
+    }, []);
+
+    // effects are only allowed to either be actually void or return actually void functions
+    React.useEffect(() => () => {});
+    // indistinguishable
+    React.useEffect(() => () => undefined);
+    // $ExpectError
+    React.useEffect(() => null);
+    // $ExpectError
+    React.useEffect(() => Math.random() ? null : undefined);
+    // $ExpectError
+    React.useEffect(() => () => null);
+    // $ExpectError
+    React.useEffect(() => () => Math.random() ? null : undefined);
+    // $ExpectError
+    React.useEffect(() => async () => {});
+    // $ExpectError
+    React.useEffect(async () => () => {});
+
+    React.useDebugValue(id, value => value.toFixed());
+    React.useDebugValue(id);
+
+    // allow passing an explicit undefined
+    React.useMemo(() => {}, undefined);
+    // but don't allow it to be missing
+    // $ExpectError
+    React.useMemo(() => {});
+
+    // useState convenience overload
+    // default to undefined only (not that useful, but type-safe -- no {} or unknown!)
+    // $ExpectType undefined
+    React.useState()[0];
+    // $ExpectType number | undefined
+    React.useState<number>()[0];
+    // default overload
+    // $ExpectType number
+    React.useState(0)[0];
+    // $ExpectType undefined
+    React.useState(undefined)[0];
+    // make sure the generic argument does reject actual potentially undefined inputs
+    // $ExpectError
+    React.useState<number>(undefined)[0];
+    // make sure useState does not widen
+    const [toggle, setToggle] = React.useState(false);
+    // $ExpectType boolean
+    toggle;
+    // make sure setState accepts a function
+    setToggle(r => !r);
+
+    // useReducer convenience overload
+
+    return React.useCallback(() => didLayout.current, []);
+}
+
+const UsesEveryHook = React.forwardRef(
+    function UsesEveryHook(props: {}, ref?: React.Ref<{ id: number }>) {
+        // $ExpectType boolean
+        useEveryHook(ref)();
+
+        return null;
+    }
+);
+const everyHookRef = React.createRef<{ id: number }>();
+<UsesEveryHook ref={everyHookRef}/>;
+
+<UsesEveryHook ref={ref => {
+    // $ExpectType { id: number; } | null
+    ref;
+ }}/>;
diff --git a/types/react/v17/test/index.ts b/types/react/v17/test/index.ts
new file mode 100644
index 00000000000000..fba058d8a32a3b
--- /dev/null
+++ b/types/react/v17/test/index.ts
@@ -0,0 +1,825 @@
+import * as React from "react";
+import * as ReactDOM from "react-dom";
+import * as ReactDOMServer from "react-dom/server";
+import * as PropTypes from "prop-types";
+import createFragment = require("react-addons-create-fragment");
+import * as LinkedStateMixin from "react-addons-linked-state-mixin";
+import * as PureRenderMixin from "react-addons-pure-render-mixin";
+import shallowCompare = require("react-addons-shallow-compare");
+import update = require("react-addons-update");
+import createReactClass = require("create-react-class");
+import * as DOM from "react-dom-factories";
+
+// NOTE: forward declarations for tests
+declare function setInterval(...args: any[]): any;
+declare function clearInterval(...args: any[]): any;
+declare var console: Console;
+interface Console {
+    log(...args: any[]): void;
+}
+
+interface Props {
+    hello: string;
+    world?: string | null | undefined;
+    foo: number;
+}
+
+interface State {
+    inputValue?: string | null | undefined;
+    seconds?: number | undefined;
+}
+
+interface Snapshot {
+    baz: string;
+}
+
+interface Context {
+    someValue?: string | null | undefined;
+}
+
+interface ChildContext {
+    someOtherValue: string;
+}
+
+interface MyComponent extends React.Component<Props, State> {
+    reset(): void;
+}
+
+// use any for ClassAttribute type sine we're using string refs
+const props: Props & React.ClassAttributes<any> = {
+    key: 42,
+    ref: "myComponent42",
+    hello: "world",
+    foo: 42
+};
+
+const scProps: SCProps = {
+    foo: 42
+};
+
+declare const container: Element;
+
+//
+// Top-Level API
+// --------------------------------------------------------------------------
+{
+    interface State {
+        inputValue: string;
+        seconds: number;
+    }
+    class SettingStateFromCtorComponent extends React.Component<Props, State, Snapshot> {
+        constructor(props: Props) {
+            super(props);
+            // $ExpectError
+            this.state = {
+                inputValue: 'hello'
+            };
+        }
+        render() { return null; }
+    }
+
+    class BadlyInitializedState extends React.Component<Props, State, Snapshot> {
+        // $ExpectError -> this throws error on TS 2.6 uncomment once TS requirement is TS >= 2.7
+        // state = {
+        //     secondz: 0,
+        //     inputValuez: 'hello'
+        // };
+        render() { return null; }
+    }
+    class BetterPropsAndStateChecksComponent extends React.Component<Props, State, Snapshot> {
+        render() { return null; }
+        componentDidMount() {
+            // $ExpectError -> this will be true in next BC release where state is gonna be `null | Readonly<S>`
+            console.log(this.state.inputValue);
+        }
+        mutateState() {
+            // $ExpectError
+            this.state = {
+                inputValue: 'hello'
+            };
+
+            // Even if state is not set, this is allowed by React
+            this.setState({ inputValue: 'hello' });
+            this.setState((prevState, props) => {
+                // $ExpectError
+                props = { foo: 'nope' };
+                // $ExpectError
+                props.foo = 'nope';
+
+                return { inputValue: prevState.inputValue + ' foo' };
+            });
+        }
+        mutateProps() {
+            // $ExpectError
+            this.props = {};
+            // $ExpectError
+            this.props = {
+                key: 42,
+                ref: "myComponent42",
+                hello: "world",
+                foo: 42
+            };
+        }
+    }
+}
+
+class ModernComponent extends React.Component<Props, State, Snapshot>
+    implements MyComponent, React.ChildContextProvider<ChildContext> {
+    static propTypes: React.ValidationMap<Props> = {
+        hello: PropTypes.string.isRequired,
+        world: PropTypes.string,
+        foo: PropTypes.number.isRequired
+    };
+
+    static contextTypes: React.ValidationMap<Context> = {
+        someValue: PropTypes.string
+    };
+
+    static childContextTypes: React.ValidationMap<ChildContext> = {
+        someOtherValue: PropTypes.string.isRequired
+    };
+
+    context: Context = {};
+
+    getChildContext() {
+        return {
+            someOtherValue: "foo"
+        };
+    }
+
+    state = {
+        inputValue: this.context.someValue,
+        seconds: this.props.foo
+    };
+
+    reset() {
+        this._myComponent.reset();
+        this.setState({
+            inputValue: this.context.someValue,
+            seconds: this.props.foo
+        });
+    }
+
+    private readonly _myComponent: MyComponent;
+    private _input: HTMLInputElement | null;
+
+    render() {
+        return DOM.div(null,
+            DOM.input({
+                ref: input => this._input = input,
+                value: this.state.inputValue ? this.state.inputValue : undefined
+            }),
+            DOM.input({
+                onChange: event => console.log(event.target)
+            }));
+    }
+
+    shouldComponentUpdate(nextProps: Props, nextState: State, nextContext: any): boolean {
+        return shallowCompare(this, nextProps, nextState);
+    }
+
+    getSnapshotBeforeUpdate(prevProps: Readonly<Props>) {
+        return { baz: `${prevProps.foo}baz` };
+    }
+
+    componentDidUpdate(prevProps: Readonly<Props>, prevState: Readonly<State>, snapshot: Snapshot) {
+        return;
+    }
+}
+
+class ModernComponentArrayRender extends React.Component<Props> {
+    render() {
+        return [DOM.h1({ key: "1" }, "1"),
+        DOM.h1({ key: "2" }, "2")];
+    }
+}
+
+class ModernComponentNoState extends React.Component<Props> { }
+class ModernComponentNoPropsAndState extends React.Component { }
+
+interface SCProps {
+    foo?: number | undefined;
+}
+
+function FunctionComponent(props: SCProps) {
+    return props.foo ? DOM.div(null, props.foo) : null;
+}
+
+// tslint:disable-next-line:no-namespace
+namespace FunctionComponent {
+    export const displayName = "FunctionComponent";
+    export const defaultProps = { foo: 42 };
+}
+
+const FunctionComponent2: React.FunctionComponent<SCProps> =
+    // props is contextually typed
+    props => DOM.div(null, props.foo);
+FunctionComponent2.displayName = "FunctionComponent2";
+FunctionComponent2.defaultProps = {
+    foo: 42
+};
+
+// allows null as props
+const FunctionComponent4: React.FunctionComponent = props => null;
+
+// undesired: Rejects `false` because of https://github.com/DefinitelyTyped/DefinitelyTyped/issues/18051
+// leaving here to document limitation and inspect error message
+const FunctionComponent5: React.FunctionComponent = () => false; // $ExpectError
+
+// React.createFactory
+const factory: React.CFactory<Props, ModernComponent> =
+    React.createFactory(ModernComponent);
+const factoryElement: React.CElement<Props, ModernComponent> =
+    factory(props);
+
+const functionComponentFactory: React.FunctionComponentFactory<SCProps> =
+    React.createFactory(FunctionComponent);
+const functionComponentFactoryElement: React.FunctionComponentElement<SCProps> =
+    functionComponentFactory(props);
+
+const legacyStatelessComponentFactory: React.SFCFactory<SCProps> =
+    React.createFactory(FunctionComponent);
+
+const domFactory: React.DOMFactory<React.DOMAttributes<{}>, Element> =
+    React.createFactory("div");
+const domFactoryElement: React.DOMElement<React.DOMAttributes<{}>, Element> =
+    domFactory();
+
+// React.createElement
+const element: React.CElement<Props, ModernComponent> = React.createElement(ModernComponent, props);
+const elementNoState: React.CElement<Props, ModernComponentNoState> = React.createElement(ModernComponentNoState, props);
+const elementNullProps: React.CElement<{}, ModernComponentNoPropsAndState> = React.createElement(ModernComponentNoPropsAndState, null);
+const functionComponentElement: React.FunctionComponentElement<SCProps> = React.createElement(FunctionComponent, scProps);
+const functionComponentElementNullProps: React.FunctionComponentElement<SCProps> = React.createElement(FunctionComponent4, null);
+const domElement: React.DOMElement<React.HTMLAttributes<HTMLDivElement>, HTMLDivElement> = React.createElement("div");
+const domElementNullProps = React.createElement("div", null);
+const htmlElement = React.createElement("input", { type: "text" });
+const inputElementNullProps: React.DOMElement<React.InputHTMLAttributes<HTMLInputElement>, HTMLInputElement> = React.createElement("input", null);
+const svgElement = React.createElement("svg", { accentHeight: 12 });
+const svgElementNullProps = React.createElement("svg", null);
+const fragmentElement: React.ReactElement<{}> = React.createElement(React.Fragment, {}, [React.createElement("div"), React.createElement("div")]);
+const fragmentElementNullProps: React.ReactElement<{}> = React.createElement(React.Fragment, null, [React.createElement("div"), React.createElement("div")]);
+
+const customProps: React.HTMLProps<HTMLElement> = props;
+const customDomElement = "my-element";
+const nonLiteralElement = React.createElement(customDomElement, customProps);
+const customDomElementNullProps = React.createElement(customDomElement, null);
+
+// https://github.com/Microsoft/TypeScript/issues/15019
+
+function foo3(child: React.ComponentClass<{ name: string }> | React.FunctionComponent<{ name: string }> | string) {
+    React.createElement(child, { name: "bar" });
+}
+
+// React.cloneElement
+const clonedElement: React.CElement<Props, ModernComponent> = React.cloneElement(element, { foo: 43 });
+
+React.cloneElement(element, {});
+React.cloneElement(element, {}, null);
+
+const clonedElement2: React.CElement<Props, ModernComponent> =
+    React.cloneElement(element, {
+        ref: c => c && c.reset()
+    });
+const clonedElement3: React.CElement<Props, ModernComponent> =
+    React.cloneElement(element, {
+        key: "8eac7",
+        foo: 55
+    });
+const clonedfunctionComponentElement: React.FunctionComponentElement<SCProps> =
+    React.cloneElement(functionComponentElement, { foo: 44 });
+// Clone base DOMElement
+const clonedDOMElement: React.DOMElement<React.HTMLAttributes<HTMLDivElement>, HTMLDivElement> =
+    React.cloneElement(domElement, {
+        className: "clonedDOMElement"
+    });
+// Clone ReactHTMLElement
+const clonedHtmlElement: React.ReactHTMLElement<HTMLInputElement> =
+    React.cloneElement(htmlElement, {
+        className: "clonedHTMLElement"
+    });
+// Clone ReactSVGElement
+const clonedSvgElement: React.ReactSVGElement =
+    React.cloneElement(svgElement, {
+        className: "clonedVGElement"
+    });
+
+// React.render
+const component: ModernComponent = ReactDOM.render(element, container);
+const componentNullContainer: ModernComponent = ReactDOM.render(element, null);
+
+const componentElementOrNull: ModernComponent = ReactDOM.render(element, container);
+const componentNoState: ModernComponentNoState = ReactDOM.render(elementNoState, container);
+const componentNoStateElementOrNull: ModernComponentNoState = ReactDOM.render(elementNoState, container);
+const domComponent: Element = ReactDOM.render(domElement, container);
+
+// Other Top-Level API
+const unmounted: boolean = ReactDOM.unmountComponentAtNode(container);
+const str: string = ReactDOMServer.renderToString(element);
+const markup: string = ReactDOMServer.renderToStaticMarkup(element);
+const notValid: boolean = React.isValidElement(props); // false
+const isValid = React.isValidElement(element); // true
+let domNode = ReactDOM.findDOMNode(component);
+domNode = ReactDOM.findDOMNode(domNode as Element);
+const fragmentType: React.ComponentType = React.Fragment;
+
+//
+// React Elements
+// --------------------------------------------------------------------------
+
+const type: React.ComponentClass<Props> = element.type;
+const elementProps: Props = element.props;
+const key = element.key;
+
+//
+// Component API
+// --------------------------------------------------------------------------
+
+// modern
+const componentState: State = component.state;
+component.setState({ inputValue: "!!!" });
+component.forceUpdate();
+
+const myComponent = component as MyComponent;
+myComponent.reset();
+
+//
+// Refs
+// --------------------------------------------------------------------------
+
+interface RCProps { }
+
+class RefComponent extends React.Component<RCProps> {
+    static create = React.createFactory(RefComponent);
+    refMethod() {
+    }
+}
+
+let componentRef: RefComponent | null = new RefComponent({});
+RefComponent.create({ ref: "componentRef" });
+// type of c should be inferred
+RefComponent.create({ ref: c => componentRef = c });
+componentRef.refMethod();
+
+let domNodeRef: Element | null;
+DOM.div({ ref: "domRef" });
+// type of node should be inferred
+DOM.div({ ref: node => domNodeRef = node });
+
+let inputNodeRef: HTMLInputElement | null;
+DOM.input({ ref: node => inputNodeRef = node as HTMLInputElement });
+
+interface ForwardingRefComponentProps {
+    hello: string;
+    world?: string | null | undefined;
+    foo: number;
+}
+
+const ForwardingRefComponent = React.forwardRef((props: ForwardingRefComponentProps, ref: React.Ref<RefComponent>) => {
+    return React.createElement(RefComponent, { ref });
+});
+
+// Declaring forwardRef render function separately (not inline).
+const ForwardRefRenderFunction = (props: ForwardingRefComponentProps, ref: React.ForwardedRef<RefComponent>)  => {
+    return React.createElement(RefComponent, { ref });
+};
+React.forwardRef(ForwardRefRenderFunction);
+
+const ForwardingRefComponentPropTypes: React.WeakValidationMap<ForwardingRefComponentProps> = {};
+ForwardingRefComponent.propTypes = ForwardingRefComponentPropTypes;
+
+// render function tests
+// need the explicit type declaration for typescript < 3.1
+const ForwardRefRenderFunctionWithPropTypes: { (): null, propTypes?: {} | undefined } = () => null;
+// Warning: forwardRef render functions do not support propTypes or defaultProps
+// $ExpectError
+React.forwardRef(ForwardRefRenderFunctionWithPropTypes);
+
+const ForwardRefRenderFunctionWithDefaultProps: { (): null, defaultProps?: {} | undefined } = () => null;
+// Warning: forwardRef render functions do not support propTypes or defaultProps
+// $ExpectError
+React.forwardRef(ForwardRefRenderFunctionWithDefaultProps);
+
+function RefCarryingComponent() {
+    const ref = React.createRef<RefComponent>();
+    // Without the explicit type argument, TypeScript infers `{ref: React.RefObject<RefComponent>}`
+    // from the second argument because both of the inferences generated by the first argument
+    // (both to the `P` in the call signature and the `P` in `defaultProps`) have low priority.
+    // Then we get a type error because `ForwardingRefComponent.defaultProps` has the wrong type.
+    // Can/should this be fixed somehow?
+    return React.createElement<React.RefAttributes<RefComponent> & ForwardingRefComponentProps>(
+        ForwardingRefComponent,
+        {
+            ref,
+            hello: 'there',
+            foo: 0,
+        },
+    );
+}
+const ForwardingRefComponent2 = React.forwardRef<HTMLElement>((props, ref) => {
+    return React.createElement('div', {
+        ref(e: HTMLDivElement) {
+            if (typeof ref === 'function') {
+                ref(e);
+            } else if (ref) {
+                ref.current = e;
+            }
+        }
+    });
+});
+
+const MemoizedForwardingRefComponent = React.memo(ForwardingRefComponent);
+const LazyComponent = React.lazy(() => Promise.resolve({ default: RefComponent }));
+
+type ClassComponentAsRef = React.ElementRef<typeof RefComponent>; // $ExpectType RefComponent
+type FunctionComponentWithoutPropsAsRef = React.ElementRef<typeof RefCarryingComponent>; // $ExpectType never
+type FunctionComponentWithPropsAsRef = React.ElementRef<typeof FunctionComponent>; // $ExpectType never
+type HTMLIntrinsicAsRef = React.ElementRef<'div'>; // $ExpectType HTMLDivElement
+type SVGIntrinsicAsRef = React.ElementRef<'svg'>; // $ExpectType SVGSVGElement
+type ForwardingRefComponentAsRef = React.ElementRef<typeof ForwardingRefComponent>; // $ExpectType RefComponent
+type MemoizedForwardingRefComponentAsRef = React.ElementRef<typeof MemoizedForwardingRefComponent>; // $ExpectType RefComponent
+type LazyComponentAsRef = React.ElementRef<typeof LazyComponent>; // $ExpectType RefComponent
+
+//
+// Attributes
+// --------------------------------------------------------------------------
+
+const children: any[] = ["Hello world", [null], DOM.span(null)];
+const divStyle: React.CSSProperties = { // CSSProperties
+    flex: "1 1 main-size",
+    backgroundImage: "url('hello.png')"
+};
+const htmlAttr: React.HTMLProps<HTMLElement> = {
+    key: 36,
+    ref: "htmlComponent",
+    children,
+    className: "test-attr",
+    style: divStyle,
+    slot: "HTMLComponent",
+    onClick: (event: React.MouseEvent<{}>) => {
+        event.preventDefault();
+        event.stopPropagation();
+    },
+    onClickCapture: (event: React.MouseEvent<{}>) => {
+        event.preventDefault();
+        event.stopPropagation();
+    },
+    onAnimationStart: event => {
+        const currentTarget: EventTarget & HTMLElement = event.currentTarget;
+    },
+    onBlur: (event: React.FocusEvent) => {
+        const {
+            // $ExpectType (EventTarget & Element) | null
+            relatedTarget,
+            // $ExpectType EventTarget & Element
+            target
+        } = event;
+    },
+    onFocus: (event: React.FocusEvent) => {
+        const {
+            // $ExpectType (EventTarget & Element) | null
+            relatedTarget,
+            // $ExpectType EventTarget & Element
+            target
+        } = event;
+    },
+    dangerouslySetInnerHTML: {
+        __html: "<strong>STRONG</strong>"
+    },
+    unselectable: 'on',
+    'aria-atomic': false,
+    'aria-checked': 'true',
+    'aria-colcount': 7,
+    'aria-label': 'test',
+    'aria-relevant': 'additions removals'
+};
+DOM.div(htmlAttr);
+DOM.span(htmlAttr);
+DOM.input(htmlAttr);
+
+DOM.svg({
+    viewBox: "0 0 48 48",
+    xmlns: "http://www.w3.org/2000/svg"
+},
+    DOM.rect({
+        className: 'foobar',
+        id: 'foo',
+        color: 'black',
+        x: 22,
+        y: 10,
+        width: 4,
+        height: 28,
+        strokeDasharray: '30%',
+        strokeDashoffset: '20%'
+    }),
+    DOM.rect({
+        x: 10,
+        y: 22,
+        width: 28,
+        height: 4,
+        strokeDasharray: 30,
+        strokeDashoffset: 20
+    }),
+    DOM.path({
+        d: "M0,0V3H3V0ZM1,1V2H2V1Z",
+        fill: "#999999",
+        fillRule: "evenodd"
+    })
+);
+
+//
+// React.Children
+// --------------------------------------------------------------------------
+
+const mappedChildrenArray: number[] =
+    React.Children.map(children, (child: any) => 42);
+const childrenArray: Array<React.ReactElement<{ p: number }>> = children;
+const mappedChildrenArrayWithKnownChildren: number[] =
+    React.Children.map(childrenArray, (child) => child.props.p);
+React.Children.forEach(children, (child) => { });
+const nChildren: number = React.Children.count(children);
+let onlyChild: React.ReactElement = React.Children.only(DOM.div()); // ok
+onlyChild = React.Children.only([null, [[["Hallo"], true]], false]); // error
+const childrenToArray: Array<Exclude<React.ReactNode, boolean | null | undefined>> = React.Children.toArray(children);
+
+declare const numberChildren: number[];
+declare const nodeChildren: React.ReactNode;
+declare const elementChildren: JSX.Element[];
+declare const mixedChildren: Array<JSX.Element | string>;
+declare const singlePluralChildren: JSX.Element | JSX.Element[];
+declare const renderPropsChildren: () => JSX.Element;
+
+// $ExpectType null
+const mappedChildrenArray0 = React.Children.map(null, num => num);
+// $ExpectType undefined
+const mappedChildrenArray1 = React.Children.map(undefined, num => num);
+// $ExpectType number[]
+const mappedChildrenArray2 = React.Children.map(numberChildren, num => num);
+// $ExpectType Element[]
+const mappedChildrenArray3 = React.Children.map(elementChildren, element => element);
+// $ExpectType (string | Element)[]
+const mappedChildrenArray4 = React.Children.map(mixedChildren, elementOrString => elementOrString);
+// This test uses a conditional type because otherwise it gets flaky and can resolve to either Key or ReactText, both
+// of which are aliases for `string | number`.
+const mappedChildrenArray5 = React.Children.map(singlePluralChildren, element => element.key);
+// $ExpectType true
+type mappedChildrenArray5Type = typeof mappedChildrenArray5 extends React.Key[] ? true : false;
+// $ExpectType string[]
+const mappedChildrenArray6 = React.Children.map(renderPropsChildren, element => element.name);
+// The return type may not be an array
+// $ExpectError
+const mappedChildrenArray7 = React.Children.map(nodeChildren, node => node).map;
+
+//
+// Example from http://facebook.github.io/react/
+// --------------------------------------------------------------------------
+
+interface TimerState {
+    secondsElapsed: number;
+}
+class Timer extends React.Component<{}, TimerState> {
+    state = {
+        secondsElapsed: 0
+    };
+    private _interval: number;
+    tick() {
+        this.setState((prevState, props) => ({
+            secondsElapsed: prevState.secondsElapsed + 1
+        }));
+    }
+    componentDidMount() {
+        this._interval = setInterval(() => this.tick(), 1000);
+    }
+    componentWillUnmount() {
+        clearInterval(this._interval);
+    }
+    render() {
+        return DOM.div(
+            null,
+            "Seconds Elapsed: ",
+            this.state.secondsElapsed
+        );
+    }
+}
+ReactDOM.render(React.createElement(Timer), container);
+
+//
+// createFragment addon
+// --------------------------------------------------------------------------
+createFragment({
+    a: DOM.div(),
+    b: ["a", false, React.createElement("span")]
+});
+
+//
+// LinkedStateMixin addon
+// --------------------------------------------------------------------------
+createReactClass({
+    mixins: [LinkedStateMixin],
+    getInitialState() {
+        return {
+            isChecked: false,
+            message: "hello!"
+        };
+    },
+    render() {
+        return DOM.div(null,
+            DOM.input({
+                type: "checkbox",
+                checkedLink: this.linkState("isChecked")
+            }),
+            DOM.input({
+                type: "text",
+                valueLink: this.linkState("message")
+            })
+        );
+    }
+});
+
+//
+// PureRenderMixin addon
+// --------------------------------------------------------------------------
+createReactClass({
+    mixins: [PureRenderMixin],
+    render() { return DOM.div(null); }
+});
+
+//
+// update addon
+// --------------------------------------------------------------------------
+{
+    // These are copied from https://facebook.github.io/react/docs/update.html
+    const initialArray = [1, 2, 3];
+    const newArray = update(initialArray, { $push: [4] }); // => [1, 2, 3, 4]
+
+    const collection = [1, 2, { a: [12, 17, 15] }];
+    const newCollection = update(collection, { 2: { a: { $splice: [[1, 1, 13, 14]] } } });
+    // => [1, 2, {a: [12, 13, 14, 15]}]
+
+    const obj = { a: 5, b: 3 };
+    const newObj = update(obj, {
+        b: {
+            $apply: (x) => x * 2
+        }
+    });
+    // => {a: 5, b: 6}
+    const newObj2 = update(obj, { b: { $set: obj.b * 2 } });
+
+    const objShallow = { a: 5, b: 3 };
+    const newObjShallow = update(obj, { $merge: { b: 6, c: 7 } }); // => {a: 5, b: 6, c: 7}
+}
+
+//
+// Events
+// --------------------------------------------------------------------------
+function eventHandler<T extends React.BaseSyntheticEvent>(e: T) {}
+
+function handler(e: React.MouseEvent) {
+    eventHandler(e);
+}
+
+const keyboardExtendsUI: React.UIEventHandler = (e: React.KeyboardEvent) => {};
+
+//
+// The SyntheticEvent.target.value should be accessible for onChange
+// --------------------------------------------------------------------------
+class SyntheticEventTargetValue extends React.Component<{}, { value: string }> {
+    state: { value: string };
+    constructor(props: {}) {
+        super(props);
+        this.state = { value: 'a' };
+    }
+    render() {
+        return DOM.textarea({
+            value: this.state.value,
+            onChange: e => {
+                const target: HTMLTextAreaElement = e.target;
+            }
+        });
+    }
+}
+
+DOM.input({
+    onChange: event => {
+        // `event.target` is guaranteed to be HTMLInputElement
+        const target: HTMLInputElement = event.target;
+    }
+});
+
+// A ChangeEvent is a valid FormEvent (maintain compatibility with existing
+// event handlers)
+
+type InputChangeEvent = React.ChangeEvent<HTMLInputElement>;
+type InputFormEvent = React.FormEvent<HTMLInputElement>;
+const changeEvent: InputChangeEvent = undefined as any;
+const formEvent: InputFormEvent = changeEvent;
+
+// defaultProps should be optional of props
+{
+    interface ComponentProps {
+        prop1: string;
+        prop2: string;
+        prop3?: string | undefined;
+    }
+    class ComponentWithDefaultProps extends React.Component<ComponentProps> {
+        static defaultProps = {
+            prop3: "default value",
+        };
+    }
+    const VariableWithAClass: React.ComponentClass<ComponentProps> = ComponentWithDefaultProps;
+}
+
+// complex React.DOMElement type
+declare var x: React.DOMElement<{
+    className: string;
+    style: {
+        height: string;
+        overflowY: "auto";
+        transition: string;
+    };
+}, Element>;
+
+// React 16 should be able to render its children directly
+class RenderChildren extends React.Component<{ children?: React.ReactNode }> {
+    render() {
+        const { children } = this.props;
+        return children !== undefined ? children : null;
+    }
+}
+
+const Memoized1 = React.memo(function Foo(props: { foo: string }) { return null; });
+React.createElement(Memoized1, { foo: 'string' });
+
+const Memoized2 = React.memo<{ bar: string }>(
+    function Bar(props: { bar: string }) { return null; },
+    (prevProps, nextProps) => prevProps.bar === nextProps.bar
+);
+React.createElement(Memoized2, { bar: 'string' });
+
+const specialSfc1: React.ExoticComponent<any> = Memoized1;
+const functionComponent: React.FunctionComponent<any> = Memoized2;
+
+const propsWithChildren: React.PropsWithChildren<Props> = {
+    hello: "world",
+    foo: 42,
+    children: React.createElement(functionComponent),
+};
+
+type UnionProps =
+    | ({ type: 'single'; value?: number } & React.RefAttributes<HTMLDivElement>)
+    | ({ type: 'multiple'; value?: number[] } & React.RefAttributes<HTMLDivElement>);
+
+// $ExpectError
+const propsWithoutRef: React.PropsWithoutRef<UnionProps> = {
+    type: 'single',
+    value: [2],
+};
+
+// JSXElemenConstructor vs Component assignability
+{
+    interface ExactProps {
+        value: 'A' | 'B';
+    }
+    interface NarrowerProps {
+        value: 'A';
+    }
+    interface WiderProps {
+        value: 'A' | 'B' | 'C';
+    }
+
+    // We don't actually care about the concrete type of `Wrapper` i.e.
+    // we don't care about the value created by `new Wrapper()`.
+    // We only care about the props we can pass to the component.
+    let Wrapper: React.JSXElementConstructor<ExactProps>;
+    // $ExpectError
+    Wrapper = class Narrower extends React.Component<NarrowerProps> {};
+    // $ExpectError
+    Wrapper = (props: NarrowerProps) => null;
+    Wrapper = class Exact extends React.Component<ExactProps> {};
+    Wrapper = (props: ExactProps) => null;
+    Wrapper = class Wider extends React.Component<WiderProps> {};
+    Wrapper = (props: WiderProps) => null;
+
+    React.createElement(Wrapper, { value: 'A' });
+    React.createElement(Wrapper, { value: 'B' });
+    // $ExpectError
+    React.createElement(Wrapper, { value: 'C' });
+}
+
+// ComponentPropsWithRef and JSXElementConstructor
+{
+    interface Props {
+        value: string;
+    }
+    type InferredProps = React.ComponentPropsWithRef<React.JSXElementConstructor<Props>>;
+    const props: Props = {
+        value: 'inferred',
+        // $ExpectError
+        notImplemented: 5
+    };
+    const inferredProps: InferredProps = {
+        value: 'inferred',
+        // $ExpectError
+        notImplemented: 5
+    };
+}
diff --git a/types/react/v17/test/managedAttributes.tsx b/types/react/v17/test/managedAttributes.tsx
new file mode 100644
index 00000000000000..494545c2100da4
--- /dev/null
+++ b/types/react/v17/test/managedAttributes.tsx
@@ -0,0 +1,276 @@
+interface LeaveMeAloneDtslint { foo: string; }
+// // Re-enable when we move @types/react to TS 3.0
+
+// import * as React from 'react';
+// import * as PropTypes from 'prop-types';
+
+// interface Props {
+//     bool?: boolean;
+//     fnc: () => any;
+//     node?: React.ReactNode;
+//     num?: number;
+//     reqNode: NonNullable<React.ReactNode>;
+//     str: string;
+// }
+
+// const propTypes = {
+//     bool: PropTypes.bool,
+//     fnc: PropTypes.func.isRequired,
+//     node: PropTypes.node,
+//     num: PropTypes.number,
+//     str: PropTypes.string.isRequired,
+//     extraStr: PropTypes.string.isRequired,
+//     extraNum: PropTypes.number
+// };
+
+// const defaultProps = {
+//     fnc: (() => 'abc') as () => any,
+//     extraBool: false,
+//     reqNode: 'text_node' as NonNullable<React.ReactNode>
+// };
+
+// class AnnotatedPropTypesAndDefaultProps extends React.Component<Props> {
+//     static propTypes = propTypes;
+//     static defaultProps = defaultProps;
+// }
+
+// const annotatedPropTypesAndDefaultPropsTests = [
+//     // $ExpectError
+//     <AnnotatedPropTypesAndDefaultProps />, // str and extraStr are required
+//     <AnnotatedPropTypesAndDefaultProps extraStr='abc' str='abc' />,
+//     // $ExpectError
+//     <AnnotatedPropTypesAndDefaultProps num='abc' />, // num type mismatch
+//     <AnnotatedPropTypesAndDefaultProps
+//         bool={true}
+//         extraBool={true}
+//         extraNum={0}
+//         extraStr='abc'
+//         fnc={console.log}
+//         node={<span />}
+//         num={0}
+//         reqNode={<span />}
+//         str='abc'
+//     />
+// ];
+
+// class UnannotatedPropTypesAndDefaultProps extends React.Component {
+//     static propTypes = propTypes;
+//     static defaultProps = defaultProps;
+// }
+
+// const unannotatedPropTypesAndDefaultPropsTests = [
+//     // $ExpectError
+//     <UnannotatedPropTypesAndDefaultProps />, // stra and extraStr are required
+//     <UnannotatedPropTypesAndDefaultProps extraStr='abc' str='abc' />,
+//     // $ExpectError
+//     <UnannotatedPropTypesAndDefaultProps extraBool={0} />, // extraBool type mismatch
+//     <UnannotatedPropTypesAndDefaultProps
+//         bool={true}
+//         extraBool={true}
+//         extraNum={0}
+//         extraStr='abc'
+//         fnc={console.log}
+//         node={<span />}
+//         num={0}
+//         reqNode={<span />}
+//         str='abc'
+//     />
+// ];
+
+// class AnnotatedPropTypes extends React.Component<Props> {
+//     static propTypes = propTypes;
+// }
+
+// const annotatedPropTypesTests = [
+//     // $ExpectError
+//     <AnnotatedPropTypes />, // str, extraStr, reqNode and fnc are required
+//     <AnnotatedPropTypes fnc={console.log} extraStr='abc' str='abc' reqNode={<span />} />,
+//     // $ExpectError
+//     <AnnotatedPropTypes fnc={console.log} extraStr='abc' str='abc' reqNode={<span />} extraBool={false} />, // extraBool doesn't exist
+//     // $ExpectError
+//     <AnnotatedPropTypes fnc={console.log} extraStr='abc' str='abc' reqNode={<span />} num='abc' />, // num type mismatch
+//     <AnnotatedPropTypes
+//         bool={false}
+//         extraNum={0}
+//         extraStr='abc'
+//         fnc={console.log}
+//         node={<React.Fragment />}
+//         num={0}
+//         reqNode={<React.Fragment />}
+//         str='abc'
+//     />
+// ];
+
+// class UnannotatedPropTypes extends React.Component {
+//     static propTypes = propTypes;
+// }
+
+// const unannotatedPropTypesTests = [
+//     // $ExpectError
+//     <UnannotatedPropTypes />, // str, extraStr and fnc are required
+//     <UnannotatedPropTypes fnc={console.log} extraStr='abc' str='abc' />,
+//     // $ExpectError
+//     <UnannotatedPropTypes fnc={console.log} extraStr='abc' str='abc' reqNode={<span />} />, // reqNode doesn't exist
+//     // $ExpectError
+//     <UnannotatedPropTypes fnc={console.log} extraStr='abc' str='abc' reqNode={<span />} num='abc' />, // num type mismatch
+//     <UnannotatedPropTypes
+//         bool={false}
+//         extraNum={0}
+//         extraStr='abc'
+//         fnc={console.log}
+//         node={<React.Fragment />}
+//         num={0}
+//         str='abc'
+//     />
+// ];
+
+// class AnnotatedDefaultProps extends React.Component<Props> {
+//     static defaultProps = defaultProps;
+// }
+
+// const annotatedDefaultPropsTests = [
+//     // $ExpectError
+//     <AnnotatedDefaultProps />, // str is required
+//     <AnnotatedDefaultProps str='abc' />,
+//     <AnnotatedDefaultProps str='abc' reqNode={<span />} />,
+//     // $ExpectError
+//     <AnnotatedDefaultProps str={() => { }} />, // str type mismatch
+//     <AnnotatedDefaultProps
+//         bool={true}
+//         extraBool={false}
+//         fnc={console.log}
+//         node={null}
+//         num={0}
+//         reqNode={undefined}
+//         str='abc'
+//     />
+// ];
+
+// class UnannotatedDefaultProps extends React.Component {
+//     static defaultProps = defaultProps;
+// }
+
+// const unannotatedDefaultPropsTests = [
+//     <UnannotatedDefaultProps />,
+//     <UnannotatedDefaultProps
+//         extraBool={true}
+//         fnc={console.log}
+//         reqNode={<span />}
+//     />
+// ];
+
+// class ComponentWithNoDefaultProps extends React.Component<Props> {}
+
+// function FunctionalComponent(props: Props) { return <>{props.reqNode}</> }
+// FunctionalComponent.defaultProps = defaultProps;
+
+// const functionalComponentTests = [
+//     // $ExpectError
+//     <FunctionalComponent />,
+//     // This is possibly a bug/limitation of TS
+//     // Even if JSX.LibraryManagedAttributes returns the correct type, it doesn't seem to work with non-classes
+//     // This also doesn't work with things typed React.SFC<P> because defaultProps will always be Partial<P>
+//     // $ExpectError
+//     <FunctionalComponent str='' />
+// ];
+
+// const MemoFunctionalComponent = React.memo(FunctionalComponent);
+// const MemoAnnotatedDefaultProps = React.memo(AnnotatedDefaultProps);
+// const LazyMemoFunctionalComponent = React.lazy(async () => ({ default: MemoFunctionalComponent }));
+// const LazyMemoAnnotatedDefaultProps = React.lazy(async () => ({ default: MemoAnnotatedDefaultProps }));
+
+// const memoTests = [
+//     // $ExpectError
+//     <MemoFunctionalComponent />,
+//     // $ExpectError won't work as long as FunctionalComponent doesn't work either
+//     <MemoFunctionalComponent str='abc' />,
+//     // $ExpectError
+//     <MemoAnnotatedDefaultProps />,
+//     <AnnotatedDefaultProps str='abc' />,
+//     // $ExpectError this doesn't work despite JSX.LibraryManagedAttributes returning the correct type
+//     <MemoAnnotatedDefaultProps str='abc' />,
+//     // $ExpectError won't work as long as FunctionalComponent doesn't work either
+//     <LazyMemoFunctionalComponent str='abc' />,
+//     // $ExpectError
+//     <LazyMemoAnnotatedDefaultProps />,
+//     // $ExpectError this doesn't work despite JSX.LibraryManagedAttributes returning the correct type
+//     <LazyMemoAnnotatedDefaultProps str='abc' />
+// ];
+
+// type AnnotatedDefaultPropsLibraryManagedAttributes = JSX.LibraryManagedAttributes<typeof AnnotatedDefaultProps, Props>;
+// // $ExpectType AnnotatedDefaultPropsLibraryManagedAttributes
+// type FunctionalComponentLibraryManagedAttributes = JSX.LibraryManagedAttributes<typeof FunctionalComponent, Props>;
+// // $ExpectType FunctionalComponentLibraryManagedAttributes
+// type MemoFunctionalComponentLibraryManagedAttributes = JSX.LibraryManagedAttributes<typeof MemoFunctionalComponent, Props>;
+// // $ExpectType FunctionalComponentLibraryManagedAttributes
+// type LazyMemoFunctionalComponentLibraryManagedAttributes = JSX.LibraryManagedAttributes<typeof LazyMemoFunctionalComponent, Props>;
+
+// const ForwardRef = React.forwardRef((props: Props, ref: React.Ref<ComponentWithNoDefaultProps>) => (
+//     <ComponentWithNoDefaultProps ref={ref} {...props}/>
+// ));
+// ForwardRef.defaultProps = defaultProps;
+
+// const forwardRefTests = [
+//     // $ExpectError
+//     <ForwardRef />,
+//     <ForwardRef
+//         fnc={console.log}
+//         reqNode={<span />}
+//         str=''
+//     />,
+//     // same bug as MemoFunctionalComponent and React.SFC-typed things
+//     // $ExpectError the type of ForwardRef.defaultProps stays Partial<P> anyway even if assigned
+//     <ForwardRef str='abc' />
+// ];
+
+// const weakComponentPropTypes = {
+//     foo: PropTypes.string,
+//     bar: PropTypes.bool.isRequired
+// };
+// interface WeakComponentProps1 {
+//     foo: any;
+//     bar: number;
+// }
+// interface WeakComponentProps2 {
+//     foo: string;
+//     bar: any;
+// }
+// interface WeakComponentProps3 {
+//     foo: any;
+//     bar: any;
+// }
+
+// // $ExpectType true
+// type weakComponentTest1 = JSX.LibraryManagedAttributes<{ propTypes: typeof weakComponentPropTypes }, any> extends {
+//     foo?: string | null
+//     bar: boolean
+// } ? true : false;
+// // $ExpectType true
+// type weakComponentTest2 = JSX.LibraryManagedAttributes<{ propTypes: typeof weakComponentPropTypes }, WeakComponentProps1> extends {
+//     foo?: string | null
+//     bar: number
+// } ? true : false;
+// // $ExpectType true
+// type weakComponentTest3 = JSX.LibraryManagedAttributes<{ propTypes: typeof weakComponentPropTypes }, WeakComponentProps2> extends {
+//     foo: string
+//     bar: boolean
+// } ? true : false;
+
+// // $ExpectError
+// const weakComponentOptionalityTest1: JSX.LibraryManagedAttributes<{ propTypes: typeof weakComponentPropTypes }, WeakComponentProps3> = { foo: '' };
+// const weakComponentOptionalityTest2: JSX.LibraryManagedAttributes<{ propTypes: typeof weakComponentPropTypes }, WeakComponentProps3> = { bar: true };
+
+// interface IndexedComponentProps {
+//     [K: string]: boolean;
+// }
+// interface WeakIndexedComponentProps {
+//     [K: string]: any;
+// }
+
+// const weakComponentIndexedTest1: JSX.LibraryManagedAttributes<{ propTypes: typeof weakComponentPropTypes }, IndexedComponentProps> = { };
+// // $ExpectError
+// const weakComponentIndexedTest2: JSX.LibraryManagedAttributes<{ propTypes: typeof weakComponentPropTypes }, IndexedComponentProps> = { foo: '' };
+// const weakComponentIndexedTest3: JSX.LibraryManagedAttributes<{ propTypes: typeof weakComponentPropTypes }, WeakIndexedComponentProps> = { foo: '' };
+// const weakComponentIndexedTest4: JSX.LibraryManagedAttributes<{ propTypes: typeof weakComponentPropTypes }, WeakIndexedComponentProps> = { foo: 4 };
+
+// const optionalUnionPropTest: JSX.LibraryManagedAttributes<{ propTypes: {} }, { optional?: string } | { optional?: number }> = {};
diff --git a/types/react/v17/test/tsx.tsx b/types/react/v17/test/tsx.tsx
new file mode 100644
index 00000000000000..75a933c5354cb7
--- /dev/null
+++ b/types/react/v17/test/tsx.tsx
@@ -0,0 +1,521 @@
+import PropTypes = require("prop-types");
+import React = require("react");
+
+interface SCProps {
+    foo?: number | undefined;
+}
+const FunctionComponent: React.FunctionComponent<SCProps> = ({ foo }: SCProps) => {
+    return <div>{foo}</div>;
+};
+FunctionComponent.displayName = "FunctionComponent3";
+FunctionComponent.defaultProps = {
+    foo: 42
+};
+<FunctionComponent />;
+<slot name="slot1"></slot>;
+// `FunctionComponent` has no `children`
+// $ExpectError
+<FunctionComponent>24</FunctionComponent>;
+
+const VoidFunctionComponent: React.VoidFunctionComponent<SCProps> = ({ foo }: SCProps) => {
+    return <div>{foo}</div>;
+};
+VoidFunctionComponent.displayName = "VoidFunctionComponent1";
+VoidFunctionComponent.defaultProps = {
+    foo: 42
+};
+<VoidFunctionComponent />;
+
+// $ExpectError
+const VoidFunctionComponent2: React.VoidFunctionComponent<SCProps> = ({ foo, children }) => {
+    return <div>{foo}{children}</div>;
+};
+VoidFunctionComponent2.displayName = "VoidFunctionComponent2";
+VoidFunctionComponent2.defaultProps = {
+    foo: 42
+};
+<VoidFunctionComponent2>24</VoidFunctionComponent2>; // $ExpectError
+
+// svg sanity check
+<svg viewBox="0 0 1000 1000">
+    <g>
+        <text x="200" y="300" strokeWidth="5" stroke="black" alignmentBaseline="middle">
+            Hello, world!
+            <animateMotion
+                path="M20,50 C20,-50 180,150 180,50 C180-50 20,150 20,50 z"
+                dur="5s"
+                repeatCount="indefinite"
+            />
+        </text>
+        <div slot="Some Div"> Hello again! </div>
+    </g>
+</svg>;
+
+// React-specific Attributes
+<div
+    defaultChecked
+    defaultValue="some value"
+    contentEditable
+    suppressContentEditableWarning
+    suppressHydrationWarning
+>
+    <b>foo</b>
+</div>;
+
+// WAI-ARIA 1.1 Attributes
+<div
+    aria-atomic={false}
+    aria-checked='true'
+    aria-colcount={7}
+    aria-label='test'
+>
+    <b>bar</b>
+</div>;
+
+// button type attribute
+<button type="submit">foo</button>;
+<button type="reset">foo</button>;
+<button type="button">foo</button>;
+<button type="botton">foo</button>; // $ExpectError
+<button type={"botton" as string}>foo</button>; // $ExpectError
+
+interface Props {
+    hello: string;
+}
+interface State {
+    foobar: string;
+}
+class ComponentWithPropsAndState extends React.Component<Props, State> {
+}
+<ComponentWithPropsAndState hello="TypeScript" />;
+
+class ComponentWithoutState extends React.Component<Props> {
+}
+<ComponentWithoutState hello="TypeScript" />;
+
+class ComponentWithoutPropsAndState extends React.Component {
+}
+<ComponentWithoutPropsAndState />;
+
+const FunctionComponentWithoutProps: React.FunctionComponent = (props) => {
+    return <div />;
+};
+<FunctionComponentWithoutProps />;
+
+// React.createContext
+const ContextWithRenderProps = React.createContext('defaultValue');
+
+// unstable APIs should not be part of the typings
+// $ExpectError
+const ContextUsingUnstableObservedBits = React.createContext(undefined, (previous, next) => 7);
+// $ExpectError
+<ContextWithRenderProps.Consumer unstable_observedBits={4}>
+    {(value: unknown) => null}
+</ContextWithRenderProps.Consumer>;
+
+// Fragments
+<div>
+    <React.Fragment>
+        <React.Fragment key="foo">
+            <span>Child 1</span>
+            <span>Child 2</span>
+        </React.Fragment>
+        <React.Fragment key="bar">
+            <span>Child 3</span>
+            <span>Child 4</span>
+        </React.Fragment>
+    </React.Fragment>
+</div>;
+
+// Strict Mode
+<div>
+    <React.StrictMode>
+        <div />
+    </React.StrictMode>
+</div>;
+
+// Below tests that setState() works properly for both regular and callback modes
+class SetStateTest extends React.Component<{}, { foo: boolean, bar: boolean }> {
+    handleSomething = () => {
+      this.setState({ foo: '' }); // $ExpectError
+      this.setState({ foo: true });
+      this.setState({ foo: true, bar: true });
+      this.setState({});
+      this.setState(null);
+      this.setState({ foo: true, foo2: true }); // $ExpectError
+      this.setState(() => ({ foo: '' })); // $ExpectError
+      this.setState(() => ({ foo: true }));
+      this.setState(() => ({ foo: true, bar: true }));
+      this.setState(() => ({ foo: true, foo2: true })); // $ExpectError
+      this.setState(() => ({ foo: '', foo2: true })); // $ExpectError
+      this.setState(() => ({ })); // ok!
+      this.setState({ foo: true, bar: undefined}); // $ExpectError
+      this.setState(prevState => (prevState.bar ? { bar: false } : null));
+    }
+}
+
+// Below tests that extended types for state work
+export abstract class SetStateTestForExtendsState<P, S extends { baseProp: string }> extends React.Component<P, S> {
+    foo() {
+        this.setState({ baseProp: 'foobar' });
+    }
+}
+
+// Below tests that & generic still works
+// This is invalid because 'S' may specify a different type for `baseProp`.
+// export abstract class SetStateTestForAndedState<P, S> extends React.Component<P, S & { baseProp: string }> {
+//        foo() {
+//            this.setState({ baseProp: 'foobar' });
+//        }
+// }
+
+interface NewProps { foo: string; }
+interface NewState { bar: string; }
+
+class ComponentWithNewLifecycles extends React.Component<NewProps, NewState, { baz: string }> {
+    static getDerivedStateFromProps: React.GetDerivedStateFromProps<NewProps, NewState> = (nextProps) => {
+        return { bar: `${nextProps.foo}bar` };
+    }
+
+    state = {
+        bar: 'foo'
+    };
+
+    getSnapshotBeforeUpdate(prevProps: Readonly<NewProps>) {
+        return { baz: `${prevProps.foo}baz` };
+    }
+
+    componentDidUpdate(prevProps: Readonly<NewProps>, prevState: Readonly<NewState>, snapshot: { baz: string }) {
+        return;
+    }
+
+    render() {
+        return this.state.bar;
+    }
+}
+<ComponentWithNewLifecycles foo="bar" />;
+
+class PureComponentWithNewLifecycles extends React.PureComponent<NewProps, NewState, { baz: string }> {
+    static getDerivedStateFromProps: React.GetDerivedStateFromProps<NewProps, NewState> = (nextProps) => {
+        return { bar: `${nextProps.foo}bar` };
+    }
+
+    state = {
+        bar: 'foo'
+    };
+
+    getSnapshotBeforeUpdate(prevProps: Readonly<NewProps>) {
+        return { baz: `${prevProps.foo}baz` };
+    }
+
+    componentDidUpdate(prevProps: Readonly<NewProps>, prevState: Readonly<NewState>, snapshot: { baz: string }) {
+        return;
+    }
+
+    render() {
+        return this.state.bar;
+    }
+}
+<PureComponentWithNewLifecycles foo="bar" />;
+
+class ComponentWithLargeState extends React.Component<{}, Record<'a'|'b'|'c', string>> {
+    static getDerivedStateFromProps: React.GetDerivedStateFromProps<{}, Record<'a'|'b'|'c', string>> = () => {
+        return { a: 'a' };
+    }
+}
+const AssignedComponentWithLargeState: React.ComponentClass = ComponentWithLargeState;
+
+const componentWithBadLifecycle = new (class extends React.Component<{}, {}, number> {})({});
+componentWithBadLifecycle.getSnapshotBeforeUpdate = () => { // $ExpectError
+    return 'number';
+};
+componentWithBadLifecycle.componentDidUpdate = (prevProps: {}, prevState: {}, snapshot?: string) => { // $ExpectError
+    return;
+};
+
+const Memoized1 = React.memo(function Foo(props: { foo: string }) { return null; });
+<Memoized1 foo='string'/>;
+
+const Memoized2 = React.memo(
+    function Bar(props: { bar: string }) { return null; },
+    (prevProps, nextProps) => prevProps.bar === nextProps.bar
+);
+<Memoized2 bar='string'/>;
+
+const Memoized3 = React.memo(class Test extends React.Component<{ x?: string | undefined }> {});
+<Memoized3 ref={ref => { if (ref) { ref.props.x; } }}/>;
+
+const memoized4Ref = React.createRef<HTMLDivElement>();
+const Memoized4 = React.memo(React.forwardRef((props: {}, ref: React.Ref<HTMLDivElement>) => <div ref={ref}/>));
+<Memoized4 ref={memoized4Ref}/>;
+
+const Memoized5 = React.memo<{ test: boolean }>(
+    prop => <>{prop.test}</>,
+    (prevProps, nextProps) => nextProps.test === prevProps.test
+);
+
+<Memoized5 test/>;
+
+const Memoized6: React.NamedExoticComponent<object> = React.memo(props => null);
+<Memoized6/>;
+// $ExpectError
+<Memoized6 foo/>;
+
+// NOTE: this test _requires_ TypeScript 3.1
+// It is passing, for what it's worth.
+// const Memoized7 = React.memo((() => {
+//     function HasDefaultProps(props: { test: boolean }) { return null; }
+//     HasDefaultProps.defaultProps = {
+//         test: true
+//     };
+//     return HasDefaultProps;
+// })());
+// // $ExpectType boolean
+// Memoized7.type.defaultProps.test;
+
+const LazyClassComponent = React.lazy(async () => ({ default: ComponentWithPropsAndState }));
+const LazyMemoized3 = React.lazy(async () => ({ default: Memoized3 }));
+const LazyRefForwarding = React.lazy(async () => ({ default: Memoized4 }));
+
+<React.Suspense fallback={<Memoized1 foo='string' />}>
+    <LazyClassComponent hello='test'/>
+    <LazyClassComponent ref={ref => { if (ref) { ref.props.hello; } }} hello='test'/>
+    <LazyMemoized3 ref={ref => { if (ref) { ref.props.x; } }}/>
+    <LazyRefForwarding ref={memoized4Ref}/>
+</React.Suspense>;
+
+<React.Suspense fallback={null}/>;
+// $ExpectError
+<React.Suspense/>;
+
+// unstable API should not be part of the typings
+// $ExpectError
+<React.Suspense fallback={null} unstable_avoidThisFallback />;
+
+class LegacyContext extends React.Component {
+    static contextTypes = { foo: PropTypes.node.isRequired };
+
+    render() {
+        // $ExpectType unknown
+        this.context;
+        return (this.context as any).foo;
+    }
+}
+
+class LegacyContextAnnotated extends React.Component {
+    static contextTypes = { foo: PropTypes.node.isRequired };
+    context: { foo: React.ReactNode } = { foo: {} as React.ReactNode };
+
+    render() {
+        // $ExpectType ReactNode
+        this.context.foo;
+        return this.context.foo;
+    }
+}
+
+class NewContext extends React.Component {
+    static contextType = ContextWithRenderProps;
+    context: React.ContextType<typeof ContextWithRenderProps> = "";
+
+    render() {
+        // $ExpectType string
+        this.context;
+        return this.context;
+    }
+}
+
+const ForwardRef = React.forwardRef((props: JSX.IntrinsicElements['div'], ref?: React.Ref<HTMLDivElement>) => <div {...props} ref={ref}/>);
+const ForwardRef2 = React.forwardRef((props: React.ComponentProps<typeof ForwardRef>, ref?: React.Ref<HTMLDivElement>) => <ForwardRef {...props} ref={ref}/>);
+const divFnRef = (ref: HTMLDivElement|null) => { /* empty */ };
+const divRef = React.createRef<HTMLDivElement>();
+
+<ForwardRef ref={divFnRef}/>;
+<ForwardRef ref={divRef}/>;
+<ForwardRef ref='string'/>; // $ExpectError
+<ForwardRef2 ref={divFnRef}/>;
+<ForwardRef2 ref={divRef}/>;
+<ForwardRef2 ref='string'/>; // $ExpectError
+
+const htmlElementFnRef = (instance: HTMLElement | null) => {};
+const htmlElementRef = React.createRef<HTMLElement>();
+<div ref={htmlElementFnRef} />;
+<div ref={htmlElementRef} />;
+// `current` is nullable
+const unsoundDivFnRef = (current: HTMLDivElement) => {};
+declare const unsoundDivObjectRef: { current: HTMLDivElement };
+// `current` is nullable but type-checks
+// this is consistent with ref objects
+// If this ever not type-checks, `<div ref={unsoundDivObjectRef}` should also fail type-checking
+<div ref={unsoundDivFnRef} />;
+<div ref={unsoundDivObjectRef} />;
+
+const newContextRef = React.createRef<NewContext>();
+<NewContext ref={newContextRef}/>;
+<NewContext ref='string'/>;
+
+const ForwardNewContext = React.forwardRef((_props: {}, ref?: React.Ref<NewContext>) => <NewContext ref={ref}/>);
+<ForwardNewContext ref={newContextRef}/>;
+<ForwardNewContext ref='string'/>; // $ExpectError
+
+const ForwardRef3 = React.forwardRef(
+    (props: JSX.IntrinsicElements['div'] & Pick<JSX.IntrinsicElements['div'] & { theme?: {} | undefined }, 'ref'|'theme'>, ref?: React.Ref<HTMLDivElement>) =>
+        <div {...props} ref={ref}/>
+);
+
+<ForwardRef3 ref={divFnRef}/>;
+<ForwardRef3 ref={divRef}/>;
+
+const { Profiler } = React;
+
+// 'id' is missing
+<Profiler />; // $ExpectError
+// 'onRender' is missing
+<Profiler id="test" />; // $ExpectError
+// 'number' is not assignable to 'string'
+<Profiler id={2} />; // $ExpectError
+
+<Profiler
+  id="test"
+  onRender={(
+    id,
+    phase,
+    actualDuration,
+    baseDuration,
+    startTime,
+    commitTime,
+    interactions
+  ) => {
+    const message = `${id} ${phase} took ${actualDuration.toFixed(2)}s actual, ${baseDuration.toFixed(2)}s base`;
+
+    const commitMessage = `commit started ${startTime.toFixed(2)} within ${commitTime}`;
+
+    const interactionsSummary = Array.from(interactions)
+      .map(interaction => {
+        return `${interaction.id}: '${interaction.name}' started at ${interaction.timestamp.toFixed(2)}`;
+      })
+      .join("\n");
+    const interactionMessage = `there were ${interactions.size} interactions:\n${interactionsSummary}`;
+  }}
+>
+  <div />
+</Profiler>;
+
+type ImgProps = React.ComponentProps<'img'>;
+const imgProps: ImgProps = {};
+// the order of the strings in the union seems to vary
+// with the typescript version, so test assignment instead
+imgProps.decoding = 'async';
+imgProps.decoding = 'auto';
+imgProps.decoding = 'sync';
+imgProps.loading = 'eager';
+imgProps.loading = 'lazy';
+// $ExpectError
+imgProps.loading = 'nonsense';
+// $ExpectError
+imgProps.decoding = 'nonsense';
+type ImgPropsWithRef = React.ComponentPropsWithRef<'img'>;
+// $ExpectType ((instance: HTMLImageElement | null) => void) | RefObject<HTMLImageElement> | null | undefined
+type ImgPropsWithRefRef = ImgPropsWithRef['ref'];
+type ImgPropsWithoutRef = React.ComponentPropsWithoutRef<'img'>;
+// $ExpectType false
+type ImgPropsHasRef = 'ref' extends keyof ImgPropsWithoutRef ? true : false;
+
+const HasClassName: React.ElementType<{ className?: string | undefined }> = 'a';
+const HasFoo: React.ElementType<{ foo: boolean }> = 'a'; // $ExpectError
+const HasFoo2: React.ElementType<{ foo: boolean }> = (props: { foo: boolean }) => null;
+const HasFoo3: React.ElementType<{ foo: boolean }> = (props: { foo: string }) => null; // $ExpectError
+const HasHref: React.ElementType<{ href?: string | undefined }> = 'a';
+const HasHref2: React.ElementType<{ href?: string | undefined }> = 'div'; // $ExpectError
+
+const CustomElement: React.ElementType = 'my-undeclared-element'; // $ExpectError
+
+// custom elements now need to be declared as intrinsic elements
+declare global {
+    namespace JSX {
+        interface IntrinsicElements {
+            'my-declared-element': {};
+        }
+    }
+}
+
+const CustomElement2: React.ElementType = 'my-declared-element';
+
+interface TestPropTypesProps {
+    foo: string;
+}
+interface TestPropTypesProps1 {
+    foo?: string | undefined;
+}
+interface TestPropTypesProps2 {
+    foo: string | null;
+}
+interface TestPropTypesProps3 {
+    foo?: string | null | undefined;
+}
+const testPropTypes = {
+    foo: PropTypes.string
+};
+type DeclaredPropTypes<P> = Required<Exclude<React.FunctionComponent<P>['propTypes'], undefined>>;
+// $ExpectType false
+type propTypesTest = typeof testPropTypes extends DeclaredPropTypes<TestPropTypesProps> ? true : false;
+// $ExpectType true
+type propTypesTest1 = typeof testPropTypes extends DeclaredPropTypes<TestPropTypesProps1> ? true : false;
+// $ExpectType true
+type propTypesTest2 = typeof testPropTypes extends DeclaredPropTypes<TestPropTypesProps2> ? true : false;
+// $ExpectType true
+type propTypesTest3 = typeof testPropTypes extends DeclaredPropTypes<TestPropTypesProps3> ? true : false;
+function CustomSelect(props: {
+    children: ReadonlyArray<
+      React.ReactElement<
+        React.ComponentPropsWithoutRef<typeof CustomSelectOption>
+      >
+    >;
+  }): JSX.Element {
+    return (
+      <div>
+        <ul>{props.children}</ul>
+        <select>
+          {React.Children.map(props.children, child => (
+            // key should be mappable from children.
+            <option key={child.key} value={child.props.value}>
+              {child.props.children}
+            </option>
+          ))}
+        </select>
+      </div>
+    );
+}
+function CustomSelectOption(props: {
+    value: string;
+    children: React.ReactNode;
+}): JSX.Element {
+    return <li data-value={props.value}>{props.children}</li>;
+}
+function Example() {
+    return (
+        <CustomSelect>
+        <CustomSelectOption value="one">One</CustomSelectOption>
+        <CustomSelectOption value="two">Two</CustomSelectOption>
+        </CustomSelect>
+    );
+}
+
+function reactNodeTests() {
+    function *createChildren() {
+        yield <div key="one">one</div>;
+        yield <div key="two">two</div>;
+    }
+
+    <div>{Object.freeze([<div key="one">one</div>, <div key="two">two</div>])}</div>;
+    <div>{new Set([<div key="one">one</div>, <div key="two">two</div>])}</div>;
+    // TODO: This warns at runtime so we should probably reject it as well
+    <div>
+        {
+            new Map([
+                ['one', <div key="one">one</div>],
+                ['two', <div key="two">two</div>],
+            ])
+        }
+    </div>;
+    <div>{createChildren()}</div>;
+}
diff --git a/types/react/v17/tsconfig.json b/types/react/v17/tsconfig.json
new file mode 100644
index 00000000000000..7e96f14a8af628
--- /dev/null
+++ b/types/react/v17/tsconfig.json
@@ -0,0 +1,34 @@
+{
+    "files": [
+        "index.d.ts",
+        "test/index.ts",
+        "test/tsx.tsx",
+        "test/cssProperties.tsx",
+        "test/elementAttributes.tsx",
+        "test/managedAttributes.tsx",
+        "test/hooks.tsx"
+    ],
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "paths": {
+            "react": ["react/v17"],
+            "react-dom": ["react-dom/v17"],
+            "react-dom/*": ["react-dom/v17/*"]
+        },
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "strictFunctionTypes": true,
+        "baseUrl": "../../",
+        "typeRoots": [
+            "../../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true,
+        "jsx": "preserve"
+    }
+}
diff --git a/types/react/v17/tslint.json b/types/react/v17/tslint.json
new file mode 100644
index 00000000000000..a77da0b0c4ae6b
--- /dev/null
+++ b/types/react/v17/tslint.json
@@ -0,0 +1,11 @@
+{
+    "extends": "@definitelytyped/dtslint/dt.json",
+    "rules": {
+        "dt-header": false,
+        "no-empty-interface": false,
+        "no-object-literal-type-assertion": false,
+        "no-unnecessary-generics": false,
+        "strict-export-declare-modifiers": false,
+        "void-return": false
+    }
+}

From 11ba977dd1463981111c9ba3f6ef9b9522ef601e Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Tue, 29 Mar 2022 19:15:48 +0200
Subject: [PATCH 19/29] Update peer deps for packages incompatible with v18

https://github.com/bvaughn/react-virtualized/blob/2e962d8f8aebc22cb1168a8d147bcaa1d27aa326/package.json#L150

react-router-navigation-core technically supports React 18 (https://github.com/winoteam/react-router-navigation/blob/v1.0.0-rc.5/packages/react-router-navigation-core/package.json#L16).
This is almost certainly not correct though considering the package is archived.
---
 types/react-router-navigation-core/tsconfig.json | 3 +++
 types/react-router-navigation/tsconfig.json      | 3 +++
 types/react-virtualized/tsconfig.json            | 5 +++++
 3 files changed, 11 insertions(+)

diff --git a/types/react-router-navigation-core/tsconfig.json b/types/react-router-navigation-core/tsconfig.json
index a9ffa87aba8b33..736cca68f14a14 100644
--- a/types/react-router-navigation-core/tsconfig.json
+++ b/types/react-router-navigation-core/tsconfig.json
@@ -6,6 +6,9 @@
         ],
         "types": [],
         "paths": {
+            "react": [
+                "react/v17"
+            ],
             "react-navigation": [
                 "react-navigation/v1"
             ],
diff --git a/types/react-router-navigation/tsconfig.json b/types/react-router-navigation/tsconfig.json
index 6b5ea552697d3e..18af7908c08b54 100644
--- a/types/react-router-navigation/tsconfig.json
+++ b/types/react-router-navigation/tsconfig.json
@@ -6,6 +6,9 @@
         ],
         "types": [],
         "paths": {
+            "react": [
+                "react/v17"
+            ],
             "react-navigation": [
                 "react-navigation/v1"
             ],
diff --git a/types/react-virtualized/tsconfig.json b/types/react-virtualized/tsconfig.json
index 22318cc53804d0..a2a4fa9e2ed65c 100644
--- a/types/react-virtualized/tsconfig.json
+++ b/types/react-virtualized/tsconfig.json
@@ -5,6 +5,11 @@
             "es6",
             "dom"
         ],
+        "paths": {
+            "react": [
+                "react/v17"
+            ]
+        },
         "jsx": "react",
         "baseUrl": "../",
         "typeRoots": [

From f78a3bb907fc287ded4ff9f40826584a45bf201e Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Tue, 29 Mar 2022 19:28:31 +0200
Subject: [PATCH 20/29] Major version is now 18

---
 types/react-dom/index.d.ts      | 6 +-----
 types/react-dom/v17/index.d.ts  | 8 --------
 types/react/index.d.ts          | 6 +-----
 types/react/v17/OTHER_FILES.txt | 2 --
 types/react/v17/index.d.ts      | 8 --------
 5 files changed, 2 insertions(+), 28 deletions(-)

diff --git a/types/react-dom/index.d.ts b/types/react-dom/index.d.ts
index d9a3f7db9aba20..98f799af98434a 100644
--- a/types/react-dom/index.d.ts
+++ b/types/react-dom/index.d.ts
@@ -1,4 +1,4 @@
-// Type definitions for React (react-dom) 17.0
+// Type definitions for React (react-dom) 18.0
 // Project: https://reactjs.org
 // Definitions by: Asana <https://asana.com>
 //                 AssureSign <http://www.assuresign.com>
@@ -10,10 +10,6 @@
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.8
 
-// NOTE: Users of the upcoming React 18 release should add a reference
-// to 'react-dom/next' in their project. See next.d.ts's top comment
-// for reference and documentation on how exactly to do it.
-
 // NOTE: Users of the `experimental` builds of React should add a reference
 // to 'react-dom/experimental' in their project. See experimental.d.ts's top comment
 // for reference and documentation on how exactly to do it.
diff --git a/types/react-dom/v17/index.d.ts b/types/react-dom/v17/index.d.ts
index d9a3f7db9aba20..83e2570656568d 100644
--- a/types/react-dom/v17/index.d.ts
+++ b/types/react-dom/v17/index.d.ts
@@ -10,14 +10,6 @@
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.8
 
-// NOTE: Users of the upcoming React 18 release should add a reference
-// to 'react-dom/next' in their project. See next.d.ts's top comment
-// for reference and documentation on how exactly to do it.
-
-// NOTE: Users of the `experimental` builds of React should add a reference
-// to 'react-dom/experimental' in their project. See experimental.d.ts's top comment
-// for reference and documentation on how exactly to do it.
-
 export as namespace ReactDOM;
 
 import {
diff --git a/types/react/index.d.ts b/types/react/index.d.ts
index 2f296f6920c45b..fc8e76ce6e44cb 100644
--- a/types/react/index.d.ts
+++ b/types/react/index.d.ts
@@ -1,4 +1,4 @@
-// Type definitions for React 17.0
+// Type definitions for React 18.0
 // Project: http://facebook.github.io/react/
 // Definitions by: Asana <https://asana.com>
 //                 AssureSign <http://www.assuresign.com>
@@ -29,10 +29,6 @@
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.8
 
-// NOTE: Users of the upcoming React 18 release should add a reference
-// to 'react/next' in their project. See next.d.ts's top comment
-// for reference and documentation on how exactly to do it.
-
 // NOTE: Users of the `experimental` builds of React should add a reference
 // to 'react/experimental' in their project. See experimental.d.ts's top comment
 // for reference and documentation on how exactly to do it.
diff --git a/types/react/v17/OTHER_FILES.txt b/types/react/v17/OTHER_FILES.txt
index a4d354fcba50c4..d830e68845ac36 100644
--- a/types/react/v17/OTHER_FILES.txt
+++ b/types/react/v17/OTHER_FILES.txt
@@ -1,4 +1,2 @@
-next.d.ts
-experimental.d.ts
 jsx-dev-runtime.d.ts
 jsx-runtime.d.ts
diff --git a/types/react/v17/index.d.ts b/types/react/v17/index.d.ts
index 2f296f6920c45b..ab6ba26e3b05c5 100644
--- a/types/react/v17/index.d.ts
+++ b/types/react/v17/index.d.ts
@@ -29,14 +29,6 @@
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.8
 
-// NOTE: Users of the upcoming React 18 release should add a reference
-// to 'react/next' in their project. See next.d.ts's top comment
-// for reference and documentation on how exactly to do it.
-
-// NOTE: Users of the `experimental` builds of React should add a reference
-// to 'react/experimental' in their project. See experimental.d.ts's top comment
-// for reference and documentation on how exactly to do it.
-
 /// <reference path="global.d.ts" />
 
 import * as CSS from 'csstype';

From c95f0bc194f1b1f811466bf03e1552cbab397a37 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Tue, 29 Mar 2022 19:45:51 +0200
Subject: [PATCH 21/29] [react-dom] Update types for v18

---
 types/react-dom/node-stream/index.d.ts   | 18 ------------
 types/react-dom/test/next-tests.tsx      | 27 -----------------
 types/react-dom/test/react-dom-tests.tsx | 37 +++++++++++++++++-------
 3 files changed, 26 insertions(+), 56 deletions(-)
 delete mode 100644 types/react-dom/node-stream/index.d.ts

diff --git a/types/react-dom/node-stream/index.d.ts b/types/react-dom/node-stream/index.d.ts
deleted file mode 100644
index 480392aaa4c83a..00000000000000
--- a/types/react-dom/node-stream/index.d.ts
+++ /dev/null
@@ -1,18 +0,0 @@
-import { ReactElement } from 'react';
-
-/**
- * Render a ReactElement to its initial HTML. This should only be used on the
- * server.
- * See https://facebook.github.io/react/docs/react-dom-stream.html#rendertostream
- */
-export function renderToStream(element: ReactElement): any;
-
-/**
- * Similar to renderToStream, except this doesn't create extra DOM attributes
- * such as data-react-id that React uses internally.
- * See https://facebook.github.io/react/docs/react-dom-stream.html#rendertostaticstream
- */
-export function renderToStaticStream(element: ReactElement): any;
-export const version: string;
-
-export as namespace ReactDOMNodeStream;
diff --git a/types/react-dom/test/next-tests.tsx b/types/react-dom/test/next-tests.tsx
index e94ad090fa74d5..ce82938506e415 100644
--- a/types/react-dom/test/next-tests.tsx
+++ b/types/react-dom/test/next-tests.tsx
@@ -1,28 +1 @@
 /// <reference types="../next"/>
-import React = require('react');
-import ReactDOMClient = require('react-dom/client');
-
-function createRoot() {
-    const root = ReactDOMClient.createRoot(document.documentElement);
-
-    root.render(<div>initial render</div>);
-
-    // only makes sense for `hydrateRoot`
-    // $ExpectError
-    ReactDOMClient.createRoot(document);
-}
-
-function hydrateRoot() {
-    const hydrateable = ReactDOMClient.hydrateRoot(document, <div>initial render</div>, {
-        identifierPrefix: 'react-18-app',
-        onRecoverableError: error => {
-            console.error(error);
-        },
-    });
-    hydrateable.render(<div>render update</div>);
-    ReactDOMClient.hydrateRoot(document, {
-        // Forgot `initialChildren`
-        // $ExpectError
-        identifierPrefix: 'react-18-app',
-    });
-}
diff --git a/types/react-dom/test/react-dom-tests.tsx b/types/react-dom/test/react-dom-tests.tsx
index 2ec52495aa930a..99b454c9457f38 100644
--- a/types/react-dom/test/react-dom-tests.tsx
+++ b/types/react-dom/test/react-dom-tests.tsx
@@ -1,7 +1,7 @@
 import * as React from 'react';
 import * as ReactDOM from 'react-dom';
+import * as ReactDOMClient from 'react-dom/client';
 import * as ReactDOMServer from 'react-dom/server';
-import * as ReactDOMNodeStream from 'react-dom/node-stream';
 import * as ReactTestUtils from 'react-dom/test-utils';
 
 declare function describe(desc: string, f: () => void): void;
@@ -91,16 +91,6 @@ describe('ReactDOMServer', () => {
     });
 });
 
-describe('ReactDOMNodeStream', () => {
-    it('renderToStream', () => {
-        const content: any = ReactDOMNodeStream.renderToStream(React.createElement('div'));
-    });
-
-    it('renderToStaticStream', () => {
-        const content: any = ReactDOMNodeStream.renderToStaticStream(React.createElement('div'));
-    });
-});
-
 describe('React dom test utils', () => {
     it('Simulate', () => {
         const element = document.createElement('div');
@@ -237,3 +227,28 @@ describe('React dom test utils', () => {
         });
     });
 });
+
+function createRoot() {
+    const root = ReactDOMClient.createRoot(document.documentElement);
+
+    root.render(<div>initial render</div>);
+
+    // only makes sense for `hydrateRoot`
+    // $ExpectError
+    ReactDOMClient.createRoot(document);
+}
+
+function hydrateRoot() {
+    const hydrateable = ReactDOMClient.hydrateRoot(document, <div>initial render</div>, {
+        identifierPrefix: 'react-18-app',
+        onRecoverableError: error => {
+            console.error(error);
+        },
+    });
+    hydrateable.render(<div>render update</div>);
+    ReactDOMClient.hydrateRoot(document, {
+        // Forgot `initialChildren`
+        // $ExpectError
+        identifierPrefix: 'react-18-app',
+    });
+}

From 1a6448c89cac19a2f1bf4c8149c76fce5a498441 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Tue, 29 Mar 2022 19:50:53 +0200
Subject: [PATCH 22/29] Move createMutableSource to experimental

---
 types/react/experimental.d.ts     | 16 ++++++++++++++++
 types/react/next.d.ts             | 27 ---------------------------
 types/react/test/experimental.tsx | 23 +++++++++++++++++++++++
 types/react/test/next.tsx         | 24 ------------------------
 4 files changed, 39 insertions(+), 51 deletions(-)

diff --git a/types/react/experimental.d.ts b/types/react/experimental.d.ts
index 33a6c69f2097a5..b83451c662915e 100644
--- a/types/react/experimental.d.ts
+++ b/types/react/experimental.d.ts
@@ -93,4 +93,20 @@ declare module '.' {
      * @see https://reactjs.org/docs/concurrent-mode-patterns.html#suspenselist
      */
     export const SuspenseList: ExoticComponent<SuspenseListProps>;
+
+    /**
+     * this should be an internal type
+     */
+     interface MutableSource<T> {
+        _source: T;
+    }
+
+    export type MutableSourceSubscribe<T> = (source: T, callback: () => void) => () => void;
+
+    // TODO: This may not be intentionally part of the experimental release considering useMutableSource is no longer available
+    /**
+     * @param source A source could be anything as long as they can be subscribed to and have a "version".
+     * @param getVersion A function returns a value which will change whenever part of the source changes.
+     */
+    export function unstable_createMutableSource<T>(source: T, getVersion: () => any): MutableSource<T>;
 }
diff --git a/types/react/next.d.ts b/types/react/next.d.ts
index c66cdc38a04b6d..68ad78f3396611 100644
--- a/types/react/next.d.ts
+++ b/types/react/next.d.ts
@@ -98,33 +98,6 @@ declare module '.' {
 
     export function useId(): string;
 
-    /**
-     * this should be an internal type
-     */
-    interface MutableSource<T> {
-        _source: T;
-    }
-
-    export type MutableSourceSubscribe<T> = (source: T, callback: () => void) => () => void;
-
-    /**
-     * @param source A source could be anything as long as they can be subscribed to and have a "version".
-     * @param getVersion A function returns a value which will change whenever part of the source changes.
-     */
-    export function unstable_createMutableSource<T>(source: T, getVersion: () => any): MutableSource<T>;
-
-    /**
-     * useMutableSource() enables React components to safely and efficiently read from a mutable external source in Concurrent Mode.
-     * The API will detect mutations that occur during a render to avoid tearing
-     * and it will automatically schedule updates when the source is mutated.
-     * @param MutableSource
-     * @param getSnapshot
-     * @param subscribe
-     *
-     * @see https://github.com/reactjs/rfcs/blob/master/text/0147-use-mutable-source.md
-     */
-    export function unstable_useMutableSource<T, TResult extends unknown>(MutableSource: MutableSource<T>, getSnapshot: (source: T) => TResult, subscribe: MutableSourceSubscribe<T>): TResult;
-
     /**
      * @param effect Imperative function that can return a cleanup function
      * @param deps If present, effect will only activate if the values in the list change.
diff --git a/types/react/test/experimental.tsx b/types/react/test/experimental.tsx
index 615d1f87815366..6395a59975caf3 100644
--- a/types/react/test/experimental.tsx
+++ b/types/react/test/experimental.tsx
@@ -22,3 +22,26 @@ import React = require('react');
     <React.Suspense fallback="Loading">A</React.Suspense>
     <React.Suspense fallback="Loading">B</React.Suspense>
 </React.SuspenseList>;
+
+// We need these Window interfaces to compile
+interface Window {
+    location: {
+        href: string;
+        pathname: string;
+    };
+    addEventListener(type: string, callback: () => void): void;
+    removeEventListener(type: string, callback: () => void): void;
+}
+
+const noop = () => {};
+
+const window: Window = { location: { href: '', pathname: '' }, addEventListener: noop, removeEventListener: noop };
+
+const locationSource = React.unstable_createMutableSource(window, () => window.location.href);
+
+const getSnapshot = (window: Window) => window.location.pathname;
+
+const subscribe: React.MutableSourceSubscribe<Window> = (window, callback) => {
+    window.addEventListener("popstate", callback);
+    return () => window.removeEventListener("popstate", callback);
+};
diff --git a/types/react/test/next.tsx b/types/react/test/next.tsx
index 8e366af1004f63..f70848be9fba28 100644
--- a/types/react/test/next.tsx
+++ b/types/react/test/next.tsx
@@ -3,28 +3,6 @@
 import React = require('react');
 
 const { useSyncExternalStore } = React;
-// We need these Window interfaces to compile
-interface Window {
-    location: {
-        href: string;
-        pathname: string;
-    };
-    addEventListener(type: string, callback: () => void): void;
-    removeEventListener(type: string, callback: () => void): void;
-}
-
-const noop = () => {};
-
-const window: Window = { location: { href: '', pathname: '' }, addEventListener: noop, removeEventListener: noop };
-
-const locationSource = React.unstable_createMutableSource(window, () => window.location.href);
-
-const getSnapshot = (window: Window) => window.location.pathname;
-
-const subscribe: React.MutableSourceSubscribe<Window> = (window, callback) => {
-    window.addEventListener("popstate", callback);
-    return () => window.removeEventListener("popstate", callback);
-};
 
 function useExperimentalHooks() {
     const [toggle, setToggle] = React.useState(false);
@@ -50,8 +28,6 @@ function useExperimentalHooks() {
     // $ExpectType () => string
     const deferredConstructible = React.useDeferredValue(Constructible);
 
-    // $ExpectType string
-    const pathName = React.unstable_useMutableSource(locationSource, getSnapshot, subscribe);
 
     React.useInsertionEffect(() => {});
     React.useInsertionEffect(() => {}, []);

From e4696f356848a2fbd1da17c95956d16937e16382 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Tue, 29 Mar 2022 19:53:43 +0200
Subject: [PATCH 23/29] Move unstable_expectedLoadTime to experimental

---
 types/react/experimental.d.ts     |  9 +++++++++
 types/react/next.d.ts             |  9 ---------
 types/react/test/experimental.tsx | 14 ++++++++++++++
 types/react/test/next.tsx         | 14 --------------
 4 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/types/react/experimental.d.ts b/types/react/experimental.d.ts
index b83451c662915e..2a620c688f0476 100644
--- a/types/react/experimental.d.ts
+++ b/types/react/experimental.d.ts
@@ -39,6 +39,15 @@ import React = require('./next');
 export {};
 
 declare module '.' {
+    export interface SuspenseProps {
+        /**
+         * The presence of this prop indicates that the content is computationally expensive to render.
+         * In other words, the tree is CPU bound and not I/O bound (e.g. due to fetching data).
+         * @see {@link https://github.com/facebook/react/pull/19936}
+         */
+        unstable_expectedLoadTime?: number | undefined;
+    }
+
     export type SuspenseListRevealOrder = 'forwards' | 'backwards' | 'together';
     export type SuspenseListTailMode = 'collapsed' | 'hidden';
 
diff --git a/types/react/next.d.ts b/types/react/next.d.ts
index 68ad78f3396611..e764c67c6fa591 100644
--- a/types/react/next.d.ts
+++ b/types/react/next.d.ts
@@ -33,15 +33,6 @@ declare const UNDEFINED_VOID_ONLY: unique symbol;
 type VoidOrUndefinedOnly = void | { [UNDEFINED_VOID_ONLY]: never };
 
 declare module '.' {
-    export interface SuspenseProps {
-        /**
-         * The presence of this prop indicates that the content is computationally expensive to render.
-         * In other words, the tree is CPU bound and not I/O bound (e.g. due to fetching data).
-         * @see {@link https://github.com/facebook/react/pull/19936}
-         */
-        unstable_expectedLoadTime?: number | undefined;
-    }
-
     // must be synchronous
     export type TransitionFunction = () => VoidOrUndefinedOnly;
     // strange definition to allow vscode to show documentation on the invocation
diff --git a/types/react/test/experimental.tsx b/types/react/test/experimental.tsx
index 6395a59975caf3..8c2f434da7318c 100644
--- a/types/react/test/experimental.tsx
+++ b/types/react/test/experimental.tsx
@@ -2,6 +2,20 @@
 
 import React = require('react');
 
+function suspenseTest() {
+    function DisplayData() {
+        return null;
+    }
+
+    function FlameChart() {
+        return (
+            <React.Suspense fallback="computing..." unstable_expectedLoadTime={2000}>
+                <DisplayData />
+            </React.Suspense>
+        );
+    }
+}
+
 // Unsupported `revealOrder` triggers a runtime warning
 // $ExpectError
 <React.SuspenseList revealOrder="something">
diff --git a/types/react/test/next.tsx b/types/react/test/next.tsx
index f70848be9fba28..a0f808a78ca517 100644
--- a/types/react/test/next.tsx
+++ b/types/react/test/next.tsx
@@ -66,20 +66,6 @@ function startTransitionTest() {
     React.startTransition(async () => {});
 }
 
-function suspenseTest() {
-    function DisplayData() {
-        return null;
-    }
-
-    function FlameChart() {
-        return (
-            <React.Suspense fallback="computing..." unstable_expectedLoadTime={2000}>
-                <DisplayData />
-            </React.Suspense>
-        );
-    }
-}
-
 function Dialog() {
     const id = React.useId();
     const nameId = `${id}-name`;

From fc646631d7babad9c985c06e2958661c6ac63874 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Tue, 29 Mar 2022 20:00:16 +0200
Subject: [PATCH 24/29] Move /next into main entrypoint

---
 types/react/index.d.ts     |  86 ++++++++++++++++++++++--
 types/react/next.d.ts      |  88 +------------------------
 types/react/test/hooks.tsx | 115 ++++++++++++++++++++++++++++++++
 types/react/test/next.tsx  | 132 -------------------------------------
 types/react/test/tsx.tsx   |   1 -
 5 files changed, 197 insertions(+), 225 deletions(-)

diff --git a/types/react/index.d.ts b/types/react/index.d.ts
index fc8e76ce6e44cb..b668622a2c62b8 100644
--- a/types/react/index.d.ts
+++ b/types/react/index.d.ts
@@ -56,6 +56,7 @@ type Booleanish = boolean | 'true' | 'false';
 declare const UNDEFINED_VOID_ONLY: unique symbol;
 // Destructors are only allowed to return void.
 type Destructor = () => void | { [UNDEFINED_VOID_ONLY]: never };
+type VoidOrUndefinedOnly = void | { [UNDEFINED_VOID_ONLY]: never };
 
 // tslint:disable-next-line:export-just-namespace
 export = React;
@@ -383,16 +384,10 @@ declare namespace React {
     interface SuspenseProps {
         children?: ReactNode | undefined;
 
-        // TODO(react18): `fallback?: ReactNode;`
         /** A fallback react tree to show when a Suspense child (like React.lazy) suspends */
-        fallback: NonNullable<ReactNode>|null;
+        fallback?: ReactNode;
     }
 
-    // TODO(react18): Updated JSDoc to reflect that Suspense works on the server.
-    /**
-     * This feature is not yet available for server-side rendering.
-     * Suspense support will be added in a later release.
-     */
     const Suspense: ExoticComponent<SuspenseProps>;
     const version: string;
 
@@ -1092,6 +1087,83 @@ declare namespace React {
     // it's just the function name without the "use" prefix.
     function useDebugValue<T>(value: T, format?: (value: T) => any): void;
 
+    // must be synchronous
+    export type TransitionFunction = () => VoidOrUndefinedOnly;
+    // strange definition to allow vscode to show documentation on the invocation
+    export interface TransitionStartFunction {
+        /**
+         * State updates caused inside the callback are allowed to be deferred.
+         *
+         * **If some state update causes a component to suspend, that state update should be wrapped in a transition.**
+         *
+         * @param callback A _synchronous_ function which causes state updates that can be deferred.
+         */
+        (callback: TransitionFunction): void;
+    }
+
+    /**
+     * Returns a deferred version of the value that may “lag behind” it for at most `timeoutMs`.
+     *
+     * This is commonly used to keep the interface responsive when you have something that renders immediately
+     * based on user input and something that needs to wait for a data fetch.
+     *
+     * A good example of this is a text input.
+     *
+     * @param value The value that is going to be deferred
+     *
+     * @see https://reactjs.org/docs/concurrent-mode-reference.html#usedeferredvalue
+     */
+    export function useDeferredValue<T>(value: T): T;
+
+    /**
+     * Allows components to avoid undesirable loading states by waiting for content to load
+     * before transitioning to the next screen. It also allows components to defer slower,
+     * data fetching updates until subsequent renders so that more crucial updates can be
+     * rendered immediately.
+     *
+     * The `useTransition` hook returns two values in an array.
+     *
+     * The first is a boolean, React’s way of informing us whether we’re waiting for the transition to finish.
+     * The second is a function that takes a callback. We can use it to tell React which state we want to defer.
+     *
+     * **If some state update causes a component to suspend, that state update should be wrapped in a transition.**
+     *
+     * @param config An optional object with `timeoutMs`
+     *
+     * @see https://reactjs.org/docs/concurrent-mode-reference.html#usetransition
+     */
+    export function useTransition(): [boolean, TransitionStartFunction];
+
+    /**
+     * Similar to `useTransition` but allows uses where hooks are not available.
+     *
+     * @param callback A _synchronous_ function which causes state updates that can be deferred.
+     */
+    export function startTransition(scope: TransitionFunction): void;
+
+    export function useId(): string;
+
+    /**
+     * @param effect Imperative function that can return a cleanup function
+     * @param deps If present, effect will only activate if the values in the list change.
+     *
+     * @see https://github.com/facebook/react/pull/21913
+     */
+     export function useInsertionEffect(effect: EffectCallback, deps?: DependencyList): void;
+
+    /**
+     * @param subscribe
+     * @param getSnapshot
+     *
+     * @see https://github.com/reactwg/react-18/discussions/86
+     */
+    // keep in sync with `useSyncExternalStore` from `use-sync-external-store`
+    export function useSyncExternalStore<Snapshot>(
+        subscribe: (onStoreChange: () => void) => () => void,
+        getSnapshot: () => Snapshot,
+        getServerSnapshot?: () => Snapshot,
+    ): Snapshot;
+
     //
     // Event System
     // ----------------------------------------------------------------------
diff --git a/types/react/next.d.ts b/types/react/next.d.ts
index e764c67c6fa591..abb81df8bf54db 100644
--- a/types/react/next.d.ts
+++ b/types/react/next.d.ts
@@ -1,7 +1,5 @@
 /**
- * These are types for things that are present in the upcoming React 18 release.
- *
- * Once React 18 is released they can just be moved to the main index file.
+ * These are types for things that are present in the React `next` release channel.
  *
  * To load the types declared here in an actual project, there are three ways. The easiest one,
  * if your `tsconfig.json` already has a `"types"` array in the `"compilerOptions"` section,
@@ -23,90 +21,10 @@
  * Either the import or the reference only needs to appear once, anywhere in the project.
  */
 
-// See https://github.com/facebook/react/blob/master/packages/react/src/React.js to see how the exports are declared,
+// See https://github.com/facebook/react/blob/main/packages/react/src/React.js to see how the exports are declared,
 
 import React = require('.');
 
 export {};
 
-declare const UNDEFINED_VOID_ONLY: unique symbol;
-type VoidOrUndefinedOnly = void | { [UNDEFINED_VOID_ONLY]: never };
-
-declare module '.' {
-    // must be synchronous
-    export type TransitionFunction = () => VoidOrUndefinedOnly;
-    // strange definition to allow vscode to show documentation on the invocation
-    export interface TransitionStartFunction {
-        /**
-         * State updates caused inside the callback are allowed to be deferred.
-         *
-         * **If some state update causes a component to suspend, that state update should be wrapped in a transition.**
-         *
-         * @param callback A _synchronous_ function which causes state updates that can be deferred.
-         */
-        (callback: TransitionFunction): void;
-    }
-
-    /**
-     * Returns a deferred version of the value that may “lag behind” it for at most `timeoutMs`.
-     *
-     * This is commonly used to keep the interface responsive when you have something that renders immediately
-     * based on user input and something that needs to wait for a data fetch.
-     *
-     * A good example of this is a text input.
-     *
-     * @param value The value that is going to be deferred
-     *
-     * @see https://reactjs.org/docs/concurrent-mode-reference.html#usedeferredvalue
-     */
-    export function useDeferredValue<T>(value: T): T;
-
-    /**
-     * Allows components to avoid undesirable loading states by waiting for content to load
-     * before transitioning to the next screen. It also allows components to defer slower,
-     * data fetching updates until subsequent renders so that more crucial updates can be
-     * rendered immediately.
-     *
-     * The `useTransition` hook returns two values in an array.
-     *
-     * The first is a boolean, React’s way of informing us whether we’re waiting for the transition to finish.
-     * The second is a function that takes a callback. We can use it to tell React which state we want to defer.
-     *
-     * **If some state update causes a component to suspend, that state update should be wrapped in a transition.**
-     *
-     * @param config An optional object with `timeoutMs`
-     *
-     * @see https://reactjs.org/docs/concurrent-mode-reference.html#usetransition
-     */
-    export function useTransition(): [boolean, TransitionStartFunction];
-
-    /**
-     * Similar to `useTransition` but allows uses where hooks are not available.
-     *
-     * @param callback A _synchronous_ function which causes state updates that can be deferred.
-     */
-    export function startTransition(scope: TransitionFunction): void;
-
-    export function useId(): string;
-
-    /**
-     * @param effect Imperative function that can return a cleanup function
-     * @param deps If present, effect will only activate if the values in the list change.
-     *
-     * @see https://github.com/facebook/react/pull/21913
-     */
-     export function useInsertionEffect(effect: EffectCallback, deps?: DependencyList): void;
-
-    /**
-     * @param subscribe
-     * @param getSnapshot
-     *
-     * @see https://github.com/reactwg/react-18/discussions/86
-     */
-    // keep in sync with `useSyncExternalStore` from `use-sync-external-store`
-    export function useSyncExternalStore<Snapshot>(
-        subscribe: (onStoreChange: () => void) => () => void,
-        getSnapshot: () => Snapshot,
-        getServerSnapshot?: () => Snapshot,
-    ): Snapshot;
-}
+declare module '.' {}
diff --git a/types/react/test/hooks.tsx b/types/react/test/hooks.tsx
index 88c32eb34d3f8e..62b1a75d61cd65 100644
--- a/types/react/test/hooks.tsx
+++ b/types/react/test/hooks.tsx
@@ -1,5 +1,7 @@
 import * as React from "react";
 
+const {useSyncExternalStore} = React;
+
 interface PersonProps {
     name: string;
     age: number;
@@ -252,3 +254,116 @@ const everyHookRef = React.createRef<{ id: number }>();
     // $ExpectType { id: number; } | null
     ref;
  }}/>;
+
+function useExperimentalHooks() {
+    const [toggle, setToggle] = React.useState(false);
+
+    const [done, startTransition] = React.useTransition();
+    // $ExpectType boolean
+    done;
+
+    // $ExpectType boolean
+    const deferredToggle = React.useDeferredValue(toggle);
+
+    const [func] = React.useState(() => () => 0);
+
+    // $ExpectType () => number
+    func;
+    // $ExpectType () => number
+    const deferredFunc = React.useDeferredValue(func);
+
+    class Constructor {}
+    // $ExpectType typeof Constructor
+    const deferredConstructor = React.useDeferredValue(Constructor);
+
+    // $ExpectType () => string
+    const deferredConstructible = React.useDeferredValue(Constructible);
+
+    React.useInsertionEffect(() => {});
+    React.useInsertionEffect(() => {}, []);
+    React.useInsertionEffect(() => {
+        return () => {};
+    }, [toggle]);
+
+    return () => {
+        startTransition(() => {
+            setToggle(toggle => !toggle);
+        });
+
+        // The function must be synchronous, even if it can start an asynchronous update
+        // it's no different from an useEffect callback in this respect
+        // $ExpectError
+        startTransition(async () => {});
+
+        // Unlike Effect callbacks, though, there is no possible destructor to return
+        // $ExpectError
+        startTransition(() => () => {});
+    };
+
+    function Constructible() {
+        return '';
+    }
+}
+
+function startTransitionTest() {
+    function transitionToPage(page: string) {}
+
+    React.startTransition(() => {
+        transitionToPage('/');
+    });
+
+    // $ExpectError
+    React.startTransition(async () => {});
+}
+
+function Dialog() {
+    const id = React.useId();
+    const nameId = `${id}-name`;
+    const descriptionId = `${id}-description`;
+
+    return (
+        <div role="dialog" aria-labelledby={nameId} aria-describedby={descriptionId}>
+            <h2 id={nameId}>Name</h2>
+            <p id={descriptionId}>Description</p>
+        </div>
+    );
+}
+
+// keep in sync with `use-sync-external-store-tests.ts`
+interface Store<State> {
+    getState(): State;
+    getServerState(): State;
+    subscribe(onStoreChange: () => void): () => void;
+}
+
+declare const numberStore: Store<number>;
+function useVersion(): number {
+    return useSyncExternalStore(numberStore.subscribe, numberStore.getState);
+}
+
+function useStoreWrong() {
+    useSyncExternalStore(
+        // no unsubscribe returned
+        // $ExpectError
+        () => {
+            return null;
+        },
+        () => 1,
+    );
+
+    // `string` is not assignable to `number`
+    // $ExpectError
+    const version: number = useSyncExternalStore(
+        () => () => {},
+        () => '1',
+    );
+}
+
+declare const objectStore: Store<{ version: { major: number; minor: number }; users: string[] }>;
+function useUsers(): string[] {
+    return useSyncExternalStore(
+        objectStore.subscribe,
+        () => objectStore.getState().users,
+        () => objectStore.getServerState().users,
+    );
+}
diff --git a/types/react/test/next.tsx b/types/react/test/next.tsx
index a0f808a78ca517..ce82938506e415 100644
--- a/types/react/test/next.tsx
+++ b/types/react/test/next.tsx
@@ -1,133 +1 @@
 /// <reference types="../next"/>
-
-import React = require('react');
-
-const { useSyncExternalStore } = React;
-
-function useExperimentalHooks() {
-    const [toggle, setToggle] = React.useState(false);
-
-    const [done, startTransition] = React.useTransition();
-    // $ExpectType boolean
-    done;
-
-    // $ExpectType boolean
-    const deferredToggle = React.useDeferredValue(toggle);
-
-    const [func] = React.useState(() => () => 0);
-
-    // $ExpectType () => number
-    func;
-    // $ExpectType () => number
-    const deferredFunc = React.useDeferredValue(func);
-
-    class Constructor {}
-    // $ExpectType typeof Constructor
-    const deferredConstructor = React.useDeferredValue(Constructor);
-
-    // $ExpectType () => string
-    const deferredConstructible = React.useDeferredValue(Constructible);
-
-
-    React.useInsertionEffect(() => {});
-    React.useInsertionEffect(() => {}, []);
-    React.useInsertionEffect(() => {
-        return () => {};
-    }, [toggle]);
-
-    return () => {
-        startTransition(() => {
-            setToggle(toggle => !toggle);
-        });
-
-        // The function must be synchronous, even if it can start an asynchronous update
-        // it's no different from an useEffect callback in this respect
-        // $ExpectError
-        startTransition(async () => {});
-
-        // Unlike Effect callbacks, though, there is no possible destructor to return
-        // $ExpectError
-        startTransition(() => () => {});
-    };
-
-    function Constructible() {
-        return '';
-    }
-}
-
-function startTransitionTest() {
-    function transitionToPage(page: string) {}
-
-    React.startTransition(() => {
-        transitionToPage('/');
-    });
-
-    // $ExpectError
-    React.startTransition(async () => {});
-}
-
-function Dialog() {
-    const id = React.useId();
-    const nameId = `${id}-name`;
-    const descriptionId = `${id}-description`;
-
-    return (
-        <div role="dialog" aria-labelledby={nameId} aria-describedby={descriptionId}>
-            <h2 id={nameId}>Name</h2>
-            <p id={descriptionId}>Description</p>
-        </div>
-    );
-}
-
-function SuspenseTest() {
-    // TODO(react18): Should not error.
-    // `fallback` is optional in React 18
-    // $ExpectError
-    <React.Suspense></React.Suspense>;
-    // TODO(react18): Should not error.
-    // `fallback` is optional in React 18.
-    // $ExpectError
-    <React.Suspense fallback={undefined}></React.Suspense>;
-    // Workaround.
-    // TODO(react18): Remove.
-    <React.Suspense fallback={undefined!}></React.Suspense>;
-}
-
-// keep in sync with `use-sync-external-store-tests.ts`
-interface Store<State> {
-    getState(): State;
-    getServerState(): State;
-    subscribe(onStoreChange: () => void): () => void;
-}
-
-declare const numberStore: Store<number>;
-function useVersion(): number {
-    return useSyncExternalStore(numberStore.subscribe, numberStore.getState);
-}
-
-function useStoreWrong() {
-    useSyncExternalStore(
-        // no unsubscribe returned
-        // $ExpectError
-        () => {
-            return null;
-        },
-        () => 1,
-    );
-
-    // `string` is not assignable to `number`
-    // $ExpectError
-    const version: number = useSyncExternalStore(
-        () => () => {},
-        () => '1',
-    );
-}
-
-declare const objectStore: Store<{ version: { major: number; minor: number }; users: string[] }>;
-function useUsers(): string[] {
-    return useSyncExternalStore(
-        objectStore.subscribe,
-        () => objectStore.getState().users,
-        () => objectStore.getServerState().users,
-    );
-}
diff --git a/types/react/test/tsx.tsx b/types/react/test/tsx.tsx
index 75a933c5354cb7..3904ee96c7e8af 100644
--- a/types/react/test/tsx.tsx
+++ b/types/react/test/tsx.tsx
@@ -285,7 +285,6 @@ const LazyRefForwarding = React.lazy(async () => ({ default: Memoized4 }));
 </React.Suspense>;
 
 <React.Suspense fallback={null}/>;
-// $ExpectError
 <React.Suspense/>;
 
 // unstable API should not be part of the typings

From 5ccad4132a6cadd29acca9b476c00e416b67b972 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Tue, 29 Mar 2022 20:15:24 +0200
Subject: [PATCH 25/29] [styled-components] Fix TS 4.7 compat issues

---
 types/styled-components/index.d.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/types/styled-components/index.d.ts b/types/styled-components/index.d.ts
index 6ba73d81f9b26e..b4141ca6284840 100644
--- a/types/styled-components/index.d.ts
+++ b/types/styled-components/index.d.ts
@@ -105,11 +105,11 @@ export type InterpolationFunction<P> = (props: P) => Interpolation<P>;
 
 type Attrs<P, A extends Partial<P>, T> = ((props: ThemedStyledProps<P, T>) => A) | A;
 
-export type ThemedGlobalStyledClassProps<P, T> = WithOptionalTheme<P, T> & {
+export type ThemedGlobalStyledClassProps<P extends { theme?: T | undefined }, T> = WithOptionalTheme<P, T> & {
     suppressMultiMountWarning?: boolean | undefined;
 };
 
-export interface GlobalStyleComponent<P, T> extends React.ComponentClass<ThemedGlobalStyledClassProps<P, T>> {}
+export interface GlobalStyleComponent<P extends { theme?: T | undefined }, T> extends React.ComponentClass<ThemedGlobalStyledClassProps<P, T>> {}
 
 // remove the call signature from StyledComponent so Interpolation can still infer InterpolationFunction
 type StyledComponentInterpolation =

From 92c2313772dd3d3eb9c55aa01deb503eca149a70 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Tue, 29 Mar 2022 22:04:00 +0200
Subject: [PATCH 26/29] [meteor] Fix TS 4.7 compat issues

---
 types/meteor/mongo.d.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/types/meteor/mongo.d.ts b/types/meteor/mongo.d.ts
index 82f7107d1b2b48..6b042fc77a1463 100644
--- a/types/meteor/mongo.d.ts
+++ b/types/meteor/mongo.d.ts
@@ -174,7 +174,7 @@ declare module 'meteor/mongo' {
              * Constructor for a Collection
              * @param name The name of the collection. If null, creates an unmanaged (unsynchronized) local collection.
              */
-            new <T, U = T>(
+            new <T extends MongoNpmModule.Document, U = T>(
                 name: string | null,
                 options?: {
                     /**
@@ -199,7 +199,7 @@ declare module 'meteor/mongo' {
                 },
             ): Collection<T, U>;
         }
-        interface Collection<T, U = T> {
+        interface Collection<T extends MongoNpmModule.Document, U = T> {
             allow<Fn extends Transform<T> = undefined>(options: {
                 insert?: ((userId: string, doc: DispatchTransform<Fn, T, U>) => boolean) | undefined;
                 update?:

From 18712b8f6d6b13801a61bd8d8d4a0103195e9d69 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Wed, 30 Mar 2022 13:41:34 +0200
Subject: [PATCH 27/29] [react-virtualized-select] Use same types as runtime
 peer dependencies

https://github.com/bvaughn/react-virtualized-select/blob/3.1.3/package.json#L128
---
 types/react-virtualized-select/tsconfig.json | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/types/react-virtualized-select/tsconfig.json b/types/react-virtualized-select/tsconfig.json
index ed27d2d5c5014b..e17f1768f42c6d 100644
--- a/types/react-virtualized-select/tsconfig.json
+++ b/types/react-virtualized-select/tsconfig.json
@@ -5,6 +5,9 @@
             "es6",
             "dom"
         ],
+        "paths": {
+            "react": ["react/v16"]
+        },
         "jsx": "react",
         "noImplicitAny": true,
         "noImplicitThis": true,

From 93ac4146c8998e03ceb95ecfffd776ecc9976b63 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Wed, 30 Mar 2022 13:51:50 +0200
Subject: [PATCH 28/29] work around definitions-parser limitation

---
 types/react-virtualized-select/tsconfig.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/types/react-virtualized-select/tsconfig.json b/types/react-virtualized-select/tsconfig.json
index e17f1768f42c6d..7b12b3ca71e06e 100644
--- a/types/react-virtualized-select/tsconfig.json
+++ b/types/react-virtualized-select/tsconfig.json
@@ -6,7 +6,7 @@
             "dom"
         ],
         "paths": {
-            "react": ["react/v16"]
+            "react": ["react/v17"]
         },
         "jsx": "react",
         "noImplicitAny": true,

From 184ad9c8dc9c39f4edea93b5fa2b62ef7cb32e98 Mon Sep 17 00:00:00 2001
From: eps1lon <silbermann.sebastian@gmail.com>
Date: Wed, 30 Mar 2022 14:09:22 +0200
Subject: [PATCH 29/29] Use typings from
 208180734633b7839fc4aaa336137b6d96f54359 for v17

---
 types/react/v17/index.d.ts     | 78 +++++++++++++++++++++++++++++-----
 types/react/v17/test/hooks.tsx |  5 ++-
 types/react/v17/test/index.ts  | 34 ++++++++++++++-
 types/react/v17/test/tsx.tsx   | 38 ++++++++++-------
 4 files changed, 125 insertions(+), 30 deletions(-)

diff --git a/types/react/v17/index.d.ts b/types/react/v17/index.d.ts
index ab6ba26e3b05c5..3b1e7ebbf24e0c 100644
--- a/types/react/v17/index.d.ts
+++ b/types/react/v17/index.d.ts
@@ -67,6 +67,10 @@ declare namespace React {
             [K in keyof JSX.IntrinsicElements]: P extends JSX.IntrinsicElements[K] ? K : never
         }[keyof JSX.IntrinsicElements] |
         ComponentType<P>;
+    /**
+     * @deprecated Please use `ElementType`
+     */
+    type ReactType<P = any> = ElementType<P>;
     type ComponentType<P = {}> = ComponentClass<P> | FunctionComponent<P>;
 
     type JSXElementConstructor<P> =
@@ -143,6 +147,11 @@ declare namespace React {
         P = Pick<ComponentProps<T>, Exclude<keyof ComponentProps<T>, 'key' | 'ref'>>
     > extends ReactElement<P, Exclude<T, number>> { }
 
+    /**
+     * @deprecated Please use `FunctionComponentElement`
+     */
+    type SFCElement<P> = FunctionComponentElement<P>;
+
     interface FunctionComponentElement<P> extends ReactElement<P, FunctionComponent<P>> {
         ref?: ('ref' extends keyof P ? P extends { ref?: infer R | undefined } ? R : never : never) | undefined;
     }
@@ -220,7 +229,7 @@ declare namespace React {
      * @deprecated Use either `ReactNode[]` if you need an array or `Iterable<ReactNode>` if its passed to a host component.
      */
     interface ReactNodeArray extends ReadonlyArray<ReactNode> {}
-    type ReactFragment = Iterable<ReactNode>;
+    type ReactFragment = {} | Iterable<ReactNode>;
     type ReactNode = ReactChild | ReactFragment | ReactPortal | boolean | null | undefined;
 
     //
@@ -459,7 +468,8 @@ declare namespace React {
          *
          * @see https://reactjs.org/docs/context.html
          */
-        context: unknown;
+        // TODO (TypeScript 3.0): unknown
+        context: any;
 
         constructor(props: Readonly<P> | P);
         /**
@@ -479,7 +489,12 @@ declare namespace React {
         forceUpdate(callback?: () => void): void;
         render(): ReactNode;
 
-        readonly props: Readonly<P>;
+        // React.Props<T> is now deprecated, which means that the `children`
+        // property is not available on `P` by default, even though you can
+        // always pass children as variadic arguments to `createElement`.
+        // In the future, if we can define its call signature conditionally
+        // on the existence of `children` in `P`, then we should remove this.
+        readonly props: Readonly<P> & Readonly<{ children?: ReactNode | undefined }>;
         state: Readonly<S>;
         /**
          * @deprecated
@@ -506,10 +521,26 @@ declare namespace React {
     // Class Interfaces
     // ----------------------------------------------------------------------
 
+    /**
+     * @deprecated as of recent React versions, function components can no
+     * longer be considered 'stateless'. Please use `FunctionComponent` instead.
+     *
+     * @see [React Hooks](https://reactjs.org/docs/hooks-intro.html)
+     */
+    type SFC<P = {}> = FunctionComponent<P>;
+
+    /**
+     * @deprecated as of recent React versions, function components can no
+     * longer be considered 'stateless'. Please use `FunctionComponent` instead.
+     *
+     * @see [React Hooks](https://reactjs.org/docs/hooks-intro.html)
+     */
+    type StatelessComponent<P = {}> = FunctionComponent<P>;
+
     type FC<P = {}> = FunctionComponent<P>;
 
     interface FunctionComponent<P = {}> {
-        (props: P, context?: any): ReactElement<any, any> | null;
+        (props: PropsWithChildren<P>, context?: any): ReactElement<any, any> | null;
         propTypes?: WeakValidationMap<P> | undefined;
         contextTypes?: ValidationMap<any> | undefined;
         defaultProps?: Partial<P> | undefined;
@@ -529,7 +560,7 @@ declare namespace React {
     type ForwardedRef<T> = ((instance: T | null) => void) | MutableRefObject<T | null> | null;
 
     interface ForwardRefRenderFunction<T, P = {}> {
-        (props: P, ref: ForwardedRef<T>): ReactElement | null;
+        (props: PropsWithChildren<P>, ref: ForwardedRef<T>): ReactElement | null;
         displayName?: string | undefined;
         // explicit rejected with `never` required due to
         // https://github.com/microsoft/TypeScript/issues/36826
@@ -543,6 +574,12 @@ declare namespace React {
         propTypes?: never | undefined;
     }
 
+    /**
+     * @deprecated Use ForwardRefRenderFunction. forwardRef doesn't accept a
+     *             "real" component.
+     */
+    interface RefForwardingComponent <T, P = {}> extends ForwardRefRenderFunction<T, P> {}
+
     interface ComponentClass<P = {}, S = ComponentState> extends StaticLifecycle<P, S> {
         new (props: P, context?: any): Component<P, S>;
         propTypes?: WeakValidationMap<P> | undefined;
@@ -817,7 +854,7 @@ declare namespace React {
 
     function memo<P extends object>(
         Component: FunctionComponent<P>,
-        propsAreEqual?: (prevProps: Readonly<P>, nextProps: Readonly<P>) => boolean
+        propsAreEqual?: (prevProps: Readonly<PropsWithChildren<P>>, nextProps: Readonly<PropsWithChildren<P>>) => boolean
     ): NamedExoticComponent<P>;
     function memo<T extends ComponentType<any>>(
         Component: T,
@@ -856,7 +893,8 @@ declare namespace React {
     // The identity check is done with the SameValue algorithm (Object.is), which is stricter than ===
     type ReducerStateWithoutAction<R extends ReducerWithoutAction<any>> =
         R extends ReducerWithoutAction<infer S> ? S : never;
-    type DependencyList = ReadonlyArray<unknown>;
+    // TODO (TypeScript 3.0): ReadonlyArray<unknown>
+    type DependencyList = ReadonlyArray<any>;
 
     // NOTE: callbacks are _only_ allowed to return either void, or a destructor.
     type EffectCallback = () => (void | Destructor);
@@ -1063,10 +1101,8 @@ declare namespace React {
      * @version 16.8.0
      * @see https://reactjs.org/docs/hooks-reference.html#usecallback
      */
-    // A specific function type would not trigger implicit any.
-    // See https://github.com/DefinitelyTyped/DefinitelyTyped/issues/52873#issuecomment-845806435 for a comparison between `Function` and more specific types.
-    // tslint:disable-next-line ban-types
-    function useCallback<T extends Function>(callback: T, deps: DependencyList): T;
+    // TODO (TypeScript 3.0): <T extends (...args: never[]) => unknown>
+    function useCallback<T extends (...args: any[]) => any>(callback: T, deps: DependencyList): T;
     /**
      * `useMemo` will only recompute the memoized value when one of the `deps` has changed.
      *
@@ -1272,6 +1308,26 @@ declare namespace React {
     // Props / DOM Attributes
     // ----------------------------------------------------------------------
 
+    /**
+     * @deprecated. This was used to allow clients to pass `ref` and `key`
+     * to `createElement`, which is no longer necessary due to intersection
+     * types. If you need to declare a props object before passing it to
+     * `createElement` or a factory, use `ClassAttributes<T>`:
+     *
+     * ```ts
+     * var b: Button | null;
+     * var props: ButtonProps & ClassAttributes<Button> = {
+     *     ref: b => button = b, // ok!
+     *     label: "I'm a Button"
+     * };
+     * ```
+     */
+    interface Props<T> {
+        children?: ReactNode | undefined;
+        key?: Key | undefined;
+        ref?: LegacyRef<T> | undefined;
+    }
+
     interface HTMLProps<T> extends AllHTMLAttributes<T>, ClassAttributes<T> {
     }
 
diff --git a/types/react/v17/test/hooks.tsx b/types/react/v17/test/hooks.tsx
index 88c32eb34d3f8e..d88143a8a5ae14 100644
--- a/types/react/v17/test/hooks.tsx
+++ b/types/react/v17/test/hooks.tsx
@@ -102,8 +102,9 @@ function useEveryHook(ref: React.Ref<{ id: number }>|undefined): () => boolean {
     // inline object, to (manually) check if autocomplete works
     React.useReducer(reducer, { age: 42, name: 'The Answer' });
 
-    // Implicit any
-    // $ExpectError
+    // TODO (TypeScript 3.0): Decide whether implicit `any` should trigger `noImplicitAny` or if it should default to `unknown` or `never`
+    // https://github.com/DefinitelyTyped/DefinitelyTyped/issues/52873
+    // $ExpectType (value: any) => any
     const anyCallback = React.useCallback(value => {
         // $ExpectType any
         return value;
diff --git a/types/react/v17/test/index.ts b/types/react/v17/test/index.ts
index fba058d8a32a3b..bec90d264c33b1 100644
--- a/types/react/v17/test/index.ts
+++ b/types/react/v17/test/index.ts
@@ -219,6 +219,24 @@ FunctionComponent2.defaultProps = {
     foo: 42
 };
 
+const LegacyStatelessComponent2: React.SFC<SCProps> =
+    // props is contextually typed
+    props => DOM.div(null, props.foo);
+LegacyStatelessComponent2.displayName = "LegacyStatelessComponent2";
+LegacyStatelessComponent2.defaultProps = {
+    foo: 42
+};
+
+const FunctionComponent3: React.FunctionComponent<SCProps> =
+    // allows usage of props.children
+    // allows null return
+    props => props.foo ? DOM.div(null, props.foo, props.children) : null;
+
+const LegacyStatelessComponent3: React.SFC<SCProps> =
+    // allows usage of props.children
+    // allows null return
+    props => props.foo ? DOM.div(null, props.foo, props.children) : null;
+
 // allows null as props
 const FunctionComponent4: React.FunctionComponent = props => null;
 
@@ -239,6 +257,8 @@ const functionComponentFactoryElement: React.FunctionComponentElement<SCProps> =
 
 const legacyStatelessComponentFactory: React.SFCFactory<SCProps> =
     React.createFactory(FunctionComponent);
+const legacyStatelessComponentFactoryElement: React.SFCElement<SCProps> =
+    legacyStatelessComponentFactory(props);
 
 const domFactory: React.DOMFactory<React.DOMAttributes<{}>, Element> =
     React.createFactory("div");
@@ -251,6 +271,8 @@ const elementNoState: React.CElement<Props, ModernComponentNoState> = React.crea
 const elementNullProps: React.CElement<{}, ModernComponentNoPropsAndState> = React.createElement(ModernComponentNoPropsAndState, null);
 const functionComponentElement: React.FunctionComponentElement<SCProps> = React.createElement(FunctionComponent, scProps);
 const functionComponentElementNullProps: React.FunctionComponentElement<SCProps> = React.createElement(FunctionComponent4, null);
+const legacyStatelessComponentElement: React.SFCElement<SCProps> = React.createElement(FunctionComponent, scProps);
+const legacyStatelessComponentElementNullProps: React.SFCElement<SCProps> = React.createElement(FunctionComponent4, null);
 const domElement: React.DOMElement<React.HTMLAttributes<HTMLDivElement>, HTMLDivElement> = React.createElement("div");
 const domElementNullProps = React.createElement("div", null);
 const htmlElement = React.createElement("input", { type: "text" });
@@ -271,6 +293,10 @@ function foo3(child: React.ComponentClass<{ name: string }> | React.FunctionComp
     React.createElement(child, { name: "bar" });
 }
 
+function foo4(child: React.ComponentClass<{ name: string }> | React.SFC<{ name: string }> | string) {
+    React.createElement(child, { name: "bar" });
+}
+
 // React.cloneElement
 const clonedElement: React.CElement<Props, ModernComponent> = React.cloneElement(element, { foo: 43 });
 
@@ -288,6 +314,8 @@ const clonedElement3: React.CElement<Props, ModernComponent> =
     });
 const clonedfunctionComponentElement: React.FunctionComponentElement<SCProps> =
     React.cloneElement(functionComponentElement, { foo: 44 });
+const clonedlegacyStatelessComponentElement: React.SFCElement<SCProps> =
+    React.cloneElement(legacyStatelessComponentElement, { foo: 44 });
 // Clone base DOMElement
 const clonedDOMElement: React.DOMElement<React.HTMLAttributes<HTMLDivElement>, HTMLDivElement> =
     React.cloneElement(domElement, {
@@ -740,7 +768,7 @@ declare var x: React.DOMElement<{
 }, Element>;
 
 // React 16 should be able to render its children directly
-class RenderChildren extends React.Component<{ children?: React.ReactNode }> {
+class RenderChildren extends React.Component {
     render() {
         const { children } = this.props;
         return children !== undefined ? children : null;
@@ -758,6 +786,10 @@ React.createElement(Memoized2, { bar: 'string' });
 
 const specialSfc1: React.ExoticComponent<any> = Memoized1;
 const functionComponent: React.FunctionComponent<any> = Memoized2;
+const sfc: React.SFC<any> = Memoized2;
+// this $ExpectError is failing on TypeScript@next
+// // $ExpectError Property '$$typeof' is missing in type
+// const specialSfc2: React.SpecialSFC = props => null;
 
 const propsWithChildren: React.PropsWithChildren<Props> = {
     hello: "world",
diff --git a/types/react/v17/test/tsx.tsx b/types/react/v17/test/tsx.tsx
index 75a933c5354cb7..60b7884ffa4e40 100644
--- a/types/react/v17/test/tsx.tsx
+++ b/types/react/v17/test/tsx.tsx
@@ -13,9 +13,15 @@ FunctionComponent.defaultProps = {
 };
 <FunctionComponent />;
 <slot name="slot1"></slot>;
-// `FunctionComponent` has no `children`
-// $ExpectError
-<FunctionComponent>24</FunctionComponent>;
+
+const FunctionComponent2: React.FunctionComponent<SCProps> = ({ foo, children }) => {
+    return <div>{foo}{children}</div>;
+};
+FunctionComponent2.displayName = "FunctionComponent4";
+FunctionComponent2.defaultProps = {
+    foo: 42
+};
+<FunctionComponent2>24</FunctionComponent2>;
 
 const VoidFunctionComponent: React.VoidFunctionComponent<SCProps> = ({ foo }: SCProps) => {
     return <div>{foo}</div>;
@@ -250,8 +256,8 @@ const Memoized4 = React.memo(React.forwardRef((props: {}, ref: React.Ref<HTMLDiv
 <Memoized4 ref={memoized4Ref}/>;
 
 const Memoized5 = React.memo<{ test: boolean }>(
-    prop => <>{prop.test}</>,
-    (prevProps, nextProps) => nextProps.test === prevProps.test
+    prop => <>{prop.test && prop.children}</>,
+    (prevProps, nextProps) => nextProps.test ? prevProps.children === nextProps.children : prevProps.test
 );
 
 <Memoized5 test/>;
@@ -296,9 +302,9 @@ class LegacyContext extends React.Component {
     static contextTypes = { foo: PropTypes.node.isRequired };
 
     render() {
-        // $ExpectType unknown
-        this.context;
-        return (this.context as any).foo;
+        // $ExpectType any
+        this.context.foo;
+        return this.context.foo;
     }
 }
 
@@ -420,14 +426,14 @@ type ImgPropsWithoutRef = React.ComponentPropsWithoutRef<'img'>;
 // $ExpectType false
 type ImgPropsHasRef = 'ref' extends keyof ImgPropsWithoutRef ? true : false;
 
-const HasClassName: React.ElementType<{ className?: string | undefined }> = 'a';
-const HasFoo: React.ElementType<{ foo: boolean }> = 'a'; // $ExpectError
-const HasFoo2: React.ElementType<{ foo: boolean }> = (props: { foo: boolean }) => null;
-const HasFoo3: React.ElementType<{ foo: boolean }> = (props: { foo: string }) => null; // $ExpectError
-const HasHref: React.ElementType<{ href?: string | undefined }> = 'a';
-const HasHref2: React.ElementType<{ href?: string | undefined }> = 'div'; // $ExpectError
+const HasClassName: React.ReactType<{ className?: string | undefined }> = 'a';
+const HasFoo: React.ReactType<{ foo: boolean }> = 'a'; // $ExpectError
+const HasFoo2: React.ReactType<{ foo: boolean }> = (props: { foo: boolean }) => null;
+const HasFoo3: React.ReactType<{ foo: boolean }> = (props: { foo: string }) => null; // $ExpectError
+const HasHref: React.ReactType<{ href?: string | undefined }> = 'a';
+const HasHref2: React.ReactType<{ href?: string | undefined }> = 'div'; // $ExpectError
 
-const CustomElement: React.ElementType = 'my-undeclared-element'; // $ExpectError
+const CustomElement: React.ReactType = 'my-undeclared-element'; // $ExpectError
 
 // custom elements now need to be declared as intrinsic elements
 declare global {
@@ -438,7 +444,7 @@ declare global {
     }
 }
 
-const CustomElement2: React.ElementType = 'my-declared-element';
+const CustomElement2: React.ReactType = 'my-declared-element';
 
 interface TestPropTypesProps {
     foo: string;