From 89134ca9aae17031e0e6a90de8a6dbf953d9dc39 Mon Sep 17 00:00:00 2001
From: Ari Perkkio <ari.perkkio@gmail.com>
Date: Wed, 19 Aug 2020 20:28:13 +0300
Subject: [PATCH] [New] `no-unstable-nested-components`: Prevent creating
 unstable components inside components

---
 README.md                                     |   1 +
 docs/rules/no-unstable-nested-components.md   | 134 +++
 index.js                                      |   1 +
 lib/rules/no-unstable-nested-components.js    | 310 ++++++
 .../rules/no-unstable-nested-components.js    | 974 ++++++++++++++++++
 5 files changed, 1420 insertions(+)
 create mode 100644 docs/rules/no-unstable-nested-components.md
 create mode 100644 lib/rules/no-unstable-nested-components.js
 create mode 100644 tests/lib/rules/no-unstable-nested-components.js

diff --git a/README.md b/README.md
index 2f09ce1e3c..c7c59913a1 100644
--- a/README.md
+++ b/README.md
@@ -132,6 +132,7 @@ Enable the rules that you would like to use.
 * [react/no-unescaped-entities](docs/rules/no-unescaped-entities.md): Detect unescaped HTML entities, which might represent malformed tags
 * [react/no-unknown-property](docs/rules/no-unknown-property.md): Prevent usage of unknown DOM property (fixable)
 * [react/no-unsafe](docs/rules/no-unsafe.md): Prevent usage of unsafe lifecycle methods
+* [react/no-unstable-nested-components](docs/rules/no-unstable-nested-components.md): Prevent creating unstable components inside components
 * [react/no-unused-prop-types](docs/rules/no-unused-prop-types.md): Prevent definitions of unused prop types
 * [react/no-unused-state](docs/rules/no-unused-state.md): Prevent definition of unused state fields
 * [react/no-will-update-set-state](docs/rules/no-will-update-set-state.md): Prevent usage of setState in componentWillUpdate
diff --git a/docs/rules/no-unstable-nested-components.md b/docs/rules/no-unstable-nested-components.md
new file mode 100644
index 0000000000..c19cb2aa13
--- /dev/null
+++ b/docs/rules/no-unstable-nested-components.md
@@ -0,0 +1,134 @@
+# Prevent creating unstable components inside components (react/no-unstable-nested-components)
+
+Creating components inside components without memoization leads to unstable components. The nested component and all its children are recreated during each re-render. Given stateful children of the nested component will lose their state on each re-render.
+
+React reconcilation performs element type comparison with [reference equality](https://github.com/facebook/react/blob/v16.13.1/packages/react-reconciler/src/ReactChildFiber.js#L407). The reference to the same element changes on each re-render when defining components inside the render block. This leads to complete recreation of the current node and all its children. As a result the virtual DOM has to do extra unnecessary work and [possible bugs are introduced](https://codepen.io/ariperkkio/pen/vYLodLB).
+
+## Rule Details
+
+The following patterns are considered warnings:
+
+```jsx
+function Component() {
+  function UnstableNestedComponent() {
+    return <div />;
+  }
+
+  return (
+    <div>
+      <UnstableNestedComponent />
+    </div>
+  );
+}
+```
+
+```jsx
+function SomeComponent({ footer: Footer }) {
+  return (
+    <div>
+      <Footer />
+    </div>
+  );
+}
+
+function Component() {
+  return (
+    <div>
+      <SomeComponent footer={() => <div />} />
+    </div>
+  );
+}
+```
+
+```jsx
+class Component extends React.Component {
+  render() {
+    function UnstableNestedComponent() {
+      return <div />;
+    }
+
+    return (
+      <div>
+        <UnstableNestedComponent />
+      </div>
+    );
+  }
+}
+```
+
+The following patterns are **not** considered warnings:
+
+```jsx
+function OutsideDefinedComponent(props) {
+  return <div />;
+}
+
+function Component() {
+  return (
+    <div>
+      <OutsideDefinedComponent />
+    </div>
+  );
+}
+```
+
+```jsx
+function Component() {
+  const MemoizedNestedComponent = React.useCallback(() => <div />, []);
+
+  return (
+    <div>
+      <MemoizedNestedComponent />
+    </div>
+  );
+}
+```
+
+By default component creation is allowed inside component props only if prop name starts with `render`. See `allowAsProps` option for disabling this limitation completely.
+
+```jsx
+function SomeComponent(props) {
+  return <div>{props.renderFooter()}</div>;
+}
+
+function Component() {
+  return (
+    <div>
+      <SomeComponent renderFooter={() => <div />} />
+    </div>
+  );
+}
+```
+
+## Rule Options
+
+```js
+...
+"react/no-unstable-nested-components": [
+  "off" | "warn" | "error",
+  { "allowAsProps": true | false }
+]
+...
+```
+
+You can allow component creation inside component props by setting `allowAsProps` option to true. When using this option make sure you are **calling** the props in the receiving component and not using them as elements.
+
+The following patterns are **not** considered warnings:
+
+```jsx
+function SomeComponent(props) {
+  return <div>{props.footer()}</div>;
+}
+
+function Component() {
+  return (
+    <div>
+      <SomeComponent footer={() => <div />} />
+    </div>
+  );
+}
+```
+
+## When Not To Use It
+
+If you are not interested in preventing bugs related to re-creation of the nested components or do not care about optimization of virtual DOM.
diff --git a/index.js b/index.js
index bc0c30a43d..e40300d7d5 100644
--- a/index.js
+++ b/index.js
@@ -74,6 +74,7 @@ const allRules = {
   'no-unescaped-entities': require('./lib/rules/no-unescaped-entities'),
   'no-unknown-property': require('./lib/rules/no-unknown-property'),
   'no-unsafe': require('./lib/rules/no-unsafe'),
+  'no-unstable-nested-components': require('./lib/rules/no-unstable-nested-components'),
   'no-unused-prop-types': require('./lib/rules/no-unused-prop-types'),
   'no-unused-state': require('./lib/rules/no-unused-state'),
   'no-will-update-set-state': require('./lib/rules/no-will-update-set-state'),
diff --git a/lib/rules/no-unstable-nested-components.js b/lib/rules/no-unstable-nested-components.js
new file mode 100644
index 0000000000..7cfc2f74fe
--- /dev/null
+++ b/lib/rules/no-unstable-nested-components.js
@@ -0,0 +1,310 @@
+/**
+ * @fileoverview Prevent creating unstable components inside components
+ * @author Ari Perkkiö
+ */
+
+'use strict';
+
+const Components = require('../util/Components');
+const docsUrl = require('../util/docsUrl');
+
+// ------------------------------------------------------------------------------
+// Constants
+// ------------------------------------------------------------------------------
+
+const ERROR_MESSAGE_WITHOUT_NAME = 'Declare this component outside parent component or memoize it.';
+const COMPONENT_AS_PROPS_INFO = ' If you want to allow component creation in props, set allowAsProps option to true.';
+const RENDER_REGEXP = /^render/;
+
+// ------------------------------------------------------------------------------
+// Helpers
+// ------------------------------------------------------------------------------
+
+/**
+ * Generate error message with given parent component name
+ * @param {String} parentName Name of the parent component
+ * @returns {String} Error message with parent component name
+ */
+function generateErrorMessageWithParentName(parentName) {
+  return `Declare this component outside parent component "${parentName}" or memoize it.`;
+}
+
+/**
+ * Get closest parent matching given matcher
+ * @param {ASTNode} node The AST node
+ * @param {Function} matcher Method used to match the parent
+ * @returns {ASTNode} The matching parent node, if any
+ */
+function getClosestMatchingParent(node, matcher) {
+  if (!node || !node.parent || node.parent.type === 'Program') {
+    return;
+  }
+
+  if (matcher(node.parent)) {
+    return node.parent;
+  }
+
+  return getClosestMatchingParent(node.parent, matcher);
+}
+
+/**
+ * Matcher used to check whether given node is a `createElement` call
+ * @param {ASTNode} node The AST node
+ * @returns {Boolean} True if node is a `createElement` call, false if not
+ */
+function isCreateElementMatcher(node) {
+  return (
+    node
+    && node.type === 'CallExpression'
+    && node.callee
+    && node.callee.property
+    && node.callee.property.name === 'createElement'
+  );
+}
+
+/**
+ * Matcher used to check whether given node is a `ObjectExpression`
+ * @param {ASTNode} node The AST node
+ * @returns {Boolean} True if node is a `ObjectExpression`, false if not
+ */
+function isObjectExpressionMatcher(node) {
+  return node && node.type === 'ObjectExpression';
+}
+
+/**
+ * Resolve the component name of given node
+ * @param {ASTNode} node The AST node of the component
+ * @returns {String} Name of the component, if any
+ */
+function resolveComponentName(node) {
+  const parentName = node.id && node.id.name;
+  if (parentName) return parentName;
+
+  return (
+    node.type === 'ArrowFunctionExpression'
+    && node.parent
+    && node.parent.id
+    && node.parent.id.name
+  );
+}
+
+// ------------------------------------------------------------------------------
+// Rule Definition
+// ------------------------------------------------------------------------------
+
+module.exports = {
+  meta: {
+    docs: {
+      description: 'Prevent creating unstable components inside components',
+      category: 'Possible Errors',
+      recommended: false,
+      url: docsUrl('no-unstable-nested-components')
+    },
+    schema: [{
+      type: 'object',
+      properties: {
+        customValidators: {
+          type: 'array',
+          items: {
+            type: 'string'
+          }
+        },
+        allowAsProps: {
+          type: 'boolean'
+        }
+      },
+      additionalProperties: false
+    }]
+  },
+
+  create: Components.detect((context, components, utils) => {
+    const allowAsProps = context.options.some((option) => option && option.allowAsProps);
+
+    /**
+     * Check whether given node is declared inside class component's render block
+     * ```jsx
+     * class Component extends React.Component {
+     *   render() {
+     *     class NestedClassComponent extends React.Component {
+     * ...
+     * ```
+     * @param {ASTNode} node The AST node being checked
+     * @returns {Boolean} True if node is inside class component's render block, false if not
+     */
+    function isInsideRenderMethod(node) {
+      const parentComponent = utils.getParentComponent();
+      if (!parentComponent || parentComponent.type !== 'ClassDeclaration') {
+        return false;
+      }
+
+      return (
+        node.parent.type === 'MethodDefinition'
+        && node.parent.key
+        && node.parent.key.name === 'render'
+      );
+    }
+
+    /**
+     * Check whether given node is a function component declared inside class component.
+     * Util's component detection fails to detect function components inside class components.
+     * ```jsx
+     * class Component extends React.Component {
+     *  render() {
+     *    const NestedComponent = () => <div />;
+     * ...
+     * ```
+     * @param {ASTNode} node The AST node being checked
+     * @returns {Boolean} True if given node a function component declared inside class component, false if not
+     */
+    function isFunctionComponentInsideClassComponent(node) {
+      const parentComponent = utils.getParentComponent();
+      const parentStatelessComponent = utils.getParentStatelessComponent();
+
+      return (
+        parentComponent
+        && parentStatelessComponent
+        && parentComponent.type === 'ClassDeclaration'
+        && utils.getStatelessComponent(parentStatelessComponent)
+        && utils.isReturningJSX(node)
+      );
+    }
+
+    /**
+     * Check whether given node is declared inside `createElement` call's props
+     * ```js
+     * React.createElement(Component, {
+     *   footer: () => React.createElement("div", null)
+     * })
+     * ```
+     * @param {ASTNode} node The AST node
+     * @returns {Boolean} True if node is declare inside `createElement` call's props, false if not
+     */
+    function isComponentInsideCreateElementsProp(node) {
+      if (!components.get(node)) {
+        return false;
+      }
+
+      const createElementParent = getClosestMatchingParent(node, isCreateElementMatcher);
+      if (
+        createElementParent
+        && createElementParent.arguments
+        && createElementParent.arguments[1] === getClosestMatchingParent(node, isObjectExpressionMatcher)) {
+        return true;
+      }
+    }
+
+    /**
+     * Check whether given node is declared inside a component prop.
+     * ```jsx
+     * <Component footer={() => <div />} />
+     * ```
+     * @param {ASTNode} node The AST node being checked
+     * @returns {Boolean} True if node is a component declared inside prop, false if not
+     */
+    function isComponentInProp(node) {
+      if (node.parent.type !== 'JSXExpressionContainer') {
+        return isComponentInsideCreateElementsProp(node);
+      }
+
+      return utils.isReturningJSX(node);
+    }
+
+    /**
+     * Check whether given node is declared inside a render prop
+     * ```jsx
+     * <Component renderFooter={() => <div />} />
+     * <Component>{() => <div />}</Component>
+     * ```
+     * @param {ASTNode} node The AST node
+     * @returns {Boolean} True if component is declared inside a render prop, false if not
+     */
+    function isComponentInRenderProp(node) {
+      if (
+        node.parent.type === 'Property'
+        && node.parent.key
+        && RENDER_REGEXP.test(node.parent.key.name)) {
+        return true;
+      }
+
+      // Check whether component is a render prop used as children, e.g. <Component>{() => <div />}</Component>
+      const propNode = node.parent.parent;
+      if (propNode && propNode.type === 'JSXElement') {
+        return true;
+      }
+
+      // Check whether prop name starts with render, e.g. <Component renderFooter={() => <div />} />
+      return (
+        propNode
+        && propNode.type === 'JSXAttribute'
+        && propNode.name
+        && propNode.name.type === 'JSXIdentifier'
+        && RENDER_REGEXP.test(propNode.name.name)
+      );
+    }
+
+    /**
+     * Check whether given node is a unstable nested component
+     * @param {ASTNode} node The AST node being checked
+     */
+    function validate(node) {
+      if (!node || !node.parent) {
+        return;
+      }
+
+      const isDeclaredInsideProps = isComponentInProp(node);
+      if (
+        !components.get(node)
+        && !isFunctionComponentInsideClassComponent(node)
+        && !isDeclaredInsideProps) {
+        return;
+      }
+
+      if (isDeclaredInsideProps && (allowAsProps || isComponentInRenderProp(node))) {
+        return;
+      }
+
+      // Prevent reporting nested class components twice
+      if (isInsideRenderMethod(node)) {
+        return;
+      }
+
+      // Get the closest parent component
+      const parentComponent = getClosestMatchingParent(
+        node,
+        (nodeToMatch) => components.get(nodeToMatch)
+      );
+
+      if (parentComponent) {
+        const parentName = resolveComponentName(parentComponent);
+
+        // Exclude lowercase parents, e.g. function createTestComponent()
+        // React-dom prevents creating lowercase components
+        if (parentName && parentName[0] === parentName[0].toLowerCase()) {
+          return;
+        }
+
+        let message = parentName
+          ? generateErrorMessageWithParentName(parentName)
+          : ERROR_MESSAGE_WITHOUT_NAME;
+
+        // Add information about allowAsProps option when component is declared inside prop
+        if (isDeclaredInsideProps && !allowAsProps) {
+          message += COMPONENT_AS_PROPS_INFO;
+        }
+
+        context.report({node, message});
+      }
+    }
+
+    // --------------------------------------------------------------------------
+    // Public
+    // --------------------------------------------------------------------------
+
+    return {
+      FunctionDeclaration(node) { validate(node); },
+      ArrowFunctionExpression(node) { validate(node); },
+      FunctionExpression(node) { validate(node); },
+      ClassDeclaration(node) { validate(node); }
+    };
+  })
+};
diff --git a/tests/lib/rules/no-unstable-nested-components.js b/tests/lib/rules/no-unstable-nested-components.js
new file mode 100644
index 0000000000..0b3ce2c04f
--- /dev/null
+++ b/tests/lib/rules/no-unstable-nested-components.js
@@ -0,0 +1,974 @@
+/**
+ * @fileoverview Prevent creating unstable components inside components
+ * @author Ari Perkkiö
+ */
+
+'use strict';
+
+// ------------------------------------------------------------------------------
+// Requirements
+// ------------------------------------------------------------------------------
+
+const RuleTester = require('eslint').RuleTester;
+const rule = require('../../../lib/rules/no-unstable-nested-components');
+
+const parserOptions = {
+  ecmaVersion: 2018,
+  sourceType: 'module',
+  ecmaFeatures: {
+    jsx: true
+  }
+};
+
+const ERROR_MESSAGE = 'Declare this component outside parent component "ParentComponent" or memoize it.';
+const ERROR_MESSAGE_WITHOUT_NAME = 'Declare this component outside parent component or memoize it.';
+const ERROR_MESSAGE_COMPONENT_AS_PROPS = `${ERROR_MESSAGE} If you want to allow component creation in props, set allowAsProps option to true.`;
+
+// ------------------------------------------------------------------------------
+// Tests
+// ------------------------------------------------------------------------------
+
+const ruleTester = new RuleTester({parserOptions});
+ruleTester.run('no-unstable-nested-components', rule, {
+  valid: [
+    {
+      code: `
+      function OutsideDefinedFunctionComponent() {
+        return <div />;
+      }
+
+      function ParentComponent() {
+        return (
+          <div>
+            <OutsideDefinedFunctionComponent />
+          </div>
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function OutsideDefinedFunctionComponent() {
+        return React.createElement("div", null);
+      }
+
+      function ParentComponent() {
+        return React.createElement(
+          "div",
+          null,
+          React.createElement(OutsideDefinedFunctionComponent, null)
+        );
+      }
+      `
+    },
+    {
+      code: `
+      const OutsideDefinedVariableComponent = () => {
+        return <div />;
+      }
+
+      function ParentComponent() {
+        return (
+          <div>
+            <OutsideDefinedVariableComponent />
+          </div>
+        );
+      }
+      `
+    },
+    {
+      code: `
+      const OutsideDefinedVariableComponent = () => {
+        return React.createElement("div", null);
+      };
+
+      function ParentComponent() {
+        return React.createElement(
+          "div",
+          null,
+          React.createElement(OutsideDefinedVariableComponent, null)
+        );
+      }
+      `
+    },
+    {
+      code: `
+      class OutsideDefinedClassComponent extends React.Component {
+        render() {
+          return <div />;
+        }
+      }
+
+      function ParentComponent() {
+        return (
+          <div>
+            <OutsideDefinedClassComponent />
+          </div>
+        );
+      }
+      `
+    },
+    {
+      code: `
+      class OutsideDefinedClassComponent extends React.Component {
+        render() {
+          return React.createElement("div", null);
+        }
+      }
+
+      function ParentComponent() {
+        return React.createElement(
+          "div",
+          null,
+          React.createElement(OutsideDefinedVariableComponent, null)
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function OutsideDefinedComponentForProps() {
+        return <div />;
+      }
+
+      function ComponentWithProps(props) {
+        return <div />;
+      }
+
+      function ParentComponent() {
+        return (
+          <ComponentWithProps
+            footer={<OutsideDefinedComponentForProps />}
+            header={<div />}
+            />
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function OutsideDefinedComponentForProps() {
+        return React.createElement("div", null);
+      }
+
+      function ComponentWithProps(props) {
+        return React.createElement("div", null);
+      }
+
+      function ParentComponent() {
+        return React.createElement(ComponentWithProps, {
+          footer: React.createElement(OutsideDefinedComponentForProps, null),
+          header: React.createElement("div", null)
+        });
+      }
+      `
+    },
+    {
+      code: `
+      function ParentComponent() {
+        const MemoizedNestedVariableComponent = React.useCallback(() => <div />, []);
+
+        return (
+          <div>
+            <MemoizedNestedVariableComponent />
+          </div>
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function ParentComponent() {
+        const MemoizedNestedVariableComponent = React.useCallback(
+          () => React.createElement("div", null),
+          []
+        );
+
+        return React.createElement(
+          "div",
+          null,
+          React.createElement(MemoizedNestedVariableComponent, null)
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function ParentComponent() {
+        const MemoizedNestedFunctionComponent = React.useCallback(
+          function () {
+            return <div />;
+          },
+          []
+        );
+
+        return (
+          <div>
+            <MemoizedNestedFunctionComponent />
+          </div>
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function ParentComponent() {
+        const MemoizedNestedVariableComponent = React.useCallback(
+          function () {
+            return React.createElement("div", null);
+          },
+          []
+        );
+
+        return React.createElement(
+          "div",
+          null,
+          React.createElement(MemoizedNestedVariableComponent, null)
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function ParentComponent(props) {
+        // Should not interfere handler declarations
+        function onClick(event) {
+          props.onClick(event.target.value);
+        }
+
+        function getOnHover() {
+          return function onHover(event) {
+            props.onHover(event.target);
+          }
+        }
+
+        return (
+          <div>
+            <button
+              onClick={onClick}
+              onHover={getOnHover()} />
+          </div>
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function ParentComponent() {
+        function getComponent() {
+          return <div />;
+        }
+
+        return (
+          <div>
+            {getComponent()}
+          </div>
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function ParentComponent() {
+        function getComponent() {
+          return React.createElement("div", null);
+        }
+
+        return React.createElement("div", null, getComponent());
+      }
+      `
+    },
+    {
+      code: `
+      function RenderPropComponent(props) {
+        return props.render({});
+      }
+
+      function ParentComponent() {
+          return (
+            <RenderPropComponent>
+              {() => <div />}
+            </RenderPropComponent>
+          );
+      }
+      `
+    },
+    {
+      code: `
+      function RenderPropComponent(props) {
+        return props.render({});
+      }
+
+      function ParentComponent() {
+        return React.createElement(
+            RenderPropComponent,
+            null,
+            () => React.createElement("div", null)
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function ParentComponent(props) {
+        return (
+          <ul>
+            {props.items.map(item => (
+              <li key={item.id}>
+                {item.name}
+              </li>
+            ))}
+          </ul>
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function ParentComponent(props) {
+        return React.createElement(
+          "ul",
+          null,
+          props.items.map(() =>
+            React.createElement(
+              "li",
+              { key: item.id },
+              item.name
+            )
+          )
+        )
+      }
+      `
+    },
+    {
+      code: `
+      function ParentComponent(props) {
+        return (
+          <ul>
+            {props.items.map(function Item(item) {
+              return (
+                <li key={item.id}>
+                  {item.name}
+                </li>
+              );
+            })}
+          </ul>
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function ParentComponent(props) {
+        return React.createElement(
+          "ul",
+          null,
+          props.items.map(function Item() {
+            return React.createElement(
+              "li",
+              { key: item.id },
+              item.name
+            );
+          })
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function createTestComponent(props) {
+        return (
+          <div />
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function createTestComponent(props) {
+        return React.createElement("div", null);
+      }
+      `
+    },
+    {
+      code: `
+      function ComponentWithProps(props) {
+        return <div>{props.footer()}</div>;
+      }
+
+      function ParentComponent() {
+        return (
+          <ComponentWithProps footer={() => <div />} />
+        );
+      }
+      `,
+      options: [{
+        allowAsProps: true
+      }]
+    },
+    {
+      code: `
+      function ComponentWithProps(props) {
+        return React.createElement("div", null, props.footer());
+      }
+
+      function ParentComponent() {
+        return React.createElement(ComponentWithProps, {
+          footer: () => React.createElement("div", null)
+        });
+      }
+      `,
+      options: [{
+        allowAsProps: true
+      }]
+    },
+    {
+      code: `
+      function ComponentForProps(props) {
+        return <div />;
+      }
+
+      function ParentComponent() {
+        return (
+          <ComponentForProps renderFooter={() => <div />} />
+        );
+      }
+      `
+    },
+    {
+      code: `
+      function ComponentForProps(props) {
+        return React.createElement("div", null);
+      }
+
+      function ParentComponent() {
+        return React.createElement(ComponentForProps, {
+          renderFooter: () => React.createElement("div", null)
+        });
+      }
+      `
+    }
+  ],
+
+  invalid: [
+    {
+      code: `
+      function ParentComponent() {
+        function UnstableNestedFunctionComponent() {
+          return <div />;
+        }
+
+        return (
+          <div>
+            <UnstableNestedFunctionComponent />
+          </div>
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      function ParentComponent() {
+        function UnstableNestedFunctionComponent() {
+          return React.createElement("div", null);
+        }
+
+        return React.createElement(
+          "div",
+          null,
+          React.createElement(UnstableNestedFunctionComponent, null)
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      function ParentComponent() {
+        const UnstableNestedVariableComponent = () => {
+          return <div />;
+        }
+
+        return (
+          <div>
+            <UnstableNestedVariableComponent />
+          </div>
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      function ParentComponent() {
+        const UnstableNestedVariableComponent = () => {
+          return React.createElement("div", null);
+        }
+
+        return React.createElement(
+          "div",
+          null,
+          React.createElement(UnstableNestedVariableComponent, null)
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      const ParentComponent = () => {
+        function UnstableNestedFunctionComponent() {
+          return <div />;
+        }
+
+        return (
+          <div>
+            <UnstableNestedFunctionComponent />
+          </div>
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      const ParentComponent = () => {
+        function UnstableNestedFunctionComponent() {
+          return React.createElement("div", null);
+        }
+
+        return React.createElement(
+          "div",
+          null,
+          React.createElement(UnstableNestedFunctionComponent, null)
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      export default () => {
+        function UnstableNestedFunctionComponent() {
+          return <div />;
+        }
+
+        return (
+          <div>
+            <UnstableNestedFunctionComponent />
+          </div>
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE_WITHOUT_NAME}]
+    },
+    {
+      code: `
+      export default () => {
+        function UnstableNestedFunctionComponent() {
+          return React.createElement("div", null);
+        }
+
+        return React.createElement(
+          "div",
+          null,
+          React.createElement(UnstableNestedFunctionComponent, null)
+        );
+      };
+      `,
+      errors: [{message: ERROR_MESSAGE_WITHOUT_NAME}]
+    },
+    {
+      code: `
+      const ParentComponent = () => {
+        const UnstableNestedVariableComponent = () => {
+          return <div />;
+        }
+
+        return (
+          <div>
+            <UnstableNestedVariableComponent />
+          </div>
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      const ParentComponent = () => {
+        const UnstableNestedVariableComponent = () => {
+          return React.createElement("div", null);
+        }
+
+        return React.createElement(
+          "div",
+          null,
+          React.createElement(UnstableNestedVariableComponent, null)
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      function ParentComponent() {
+        class UnstableNestedClassComponent extends React.Component {
+          render() {
+            return <div />;
+          }
+        };
+
+        return (
+          <div>
+            <UnstableNestedClassComponent />
+          </div>
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      function ParentComponent() {
+        class UnstableNestedClassComponent extends React.Component {
+          render() {
+            return React.createElement("div", null);
+          }
+        }
+
+        return React.createElement(
+          "div",
+          null,
+          React.createElement(UnstableNestedClassComponent, null)
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      class ParentComponent extends React.Component {
+        render() {
+          class UnstableNestedClassComponent extends React.Component {
+            render() {
+              return <div />;
+            }
+          };
+
+          return (
+            <div>
+              <UnstableNestedClassComponent />
+            </div>
+          );
+        }
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      class ParentComponent extends React.Component {
+        render() {
+          class UnstableNestedClassComponent extends React.Component {
+            render() {
+              return React.createElement("div", null);
+            }
+          }
+
+          return React.createElement(
+            "div",
+            null,
+            React.createElement(UnstableNestedClassComponent, null)
+          );
+        }
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      class ParentComponent extends React.Component {
+        render() {
+          function UnstableNestedFunctionComponent() {
+            return <div />;
+          }
+
+          return (
+            <div>
+              <UnstableNestedFunctionComponent />
+            </div>
+          );
+        }
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      class ParentComponent extends React.Component {
+        render() {
+          function UnstableNestedClassComponent() {
+            return React.createElement("div", null);
+          }
+
+          return React.createElement(
+            "div",
+            null,
+            React.createElement(UnstableNestedClassComponent, null)
+          );
+        }
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      class ParentComponent extends React.Component {
+        render() {
+          const UnstableNestedVariableComponent = () => {
+            return <div />;
+          }
+
+          return (
+            <div>
+              <UnstableNestedVariableComponent />
+            </div>
+          );
+        }
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      class ParentComponent extends React.Component {
+        render() {
+          const UnstableNestedClassComponent = () => {
+            return React.createElement("div", null);
+          }
+
+          return React.createElement(
+            "div",
+            null,
+            React.createElement(UnstableNestedClassComponent, null)
+          );
+        }
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      function ParentComponent() {
+        function getComponent() {
+          function NestedUnstableFunctionComponent() {
+            return <div />;
+          };
+
+          return <NestedUnstableFunctionComponent />;
+        }
+
+        return (
+          <div>
+            {getComponent()}
+          </div>
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      function ParentComponent() {
+        function getComponent() {
+          function NestedUnstableFunctionComponent() {
+            return React.createElement("div", null);
+          }
+
+          return React.createElement(NestedUnstableFunctionComponent, null);
+        }
+
+        return React.createElement("div", null, getComponent());
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      function ParentComponent() {
+        return (
+          <div>
+            {(() => {
+              function InlinedJSXComponent() {
+                return <div />;
+              }
+
+              return <InlinedJSXComponent />;
+            })()}
+          </div>
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      function ParentComponent() {
+        return React.createElement("div", null, function () {
+          function InlinedJSXComponent() {
+            return React.createElement("div", null);
+          }
+
+          return React.createElement(InlinedJSXComponent, null);
+        }());
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      function ComponentWithProps(props) {
+        return <div />;
+      }
+
+      function ParentComponent() {
+        return (
+          <ComponentWithProps
+            footer={
+              function SomeFooter() {
+                return <div />;
+              }
+            } />
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE_COMPONENT_AS_PROPS}]
+    },
+    {
+      code: `
+      function ComponentWithProps(props) {
+        return React.createElement("div", null);
+      }
+
+      function ParentComponent() {
+        return React.createElement(ComponentWithProps, {
+          footer: function SomeFooter() {
+            return React.createElement("div", null);
+          }
+        });
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE_COMPONENT_AS_PROPS}]
+    },
+    {
+      code: `
+      function ComponentWithProps(props) {
+        return <div />;
+      }
+
+      function ParentComponent() {
+          return (
+            <ComponentWithProps footer={() => <div />} />
+          );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE_COMPONENT_AS_PROPS}]
+    },
+    {
+      code: `
+      function ComponentWithProps(props) {
+        return React.createElement("div", null);
+      }
+
+      function ParentComponent() {
+        return React.createElement(ComponentWithProps, {
+          footer: () => React.createElement("div", null)
+        });
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE_COMPONENT_AS_PROPS}]
+    },
+    {
+      code: `
+      function RenderPropComponent(props) {
+        return props.render({});
+      }
+
+      function ParentComponent() {
+          return (
+            <RenderPropComponent>
+              {() => {
+                function UnstableNestedComponent() {
+                  return <div />;
+                }
+
+                return (
+                  <div>
+                    <UnstableNestedComponent />
+                  </div>
+                );
+              }}
+            </RenderPropComponent>
+          );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      function RenderPropComponent(props) {
+        return props.render({});
+      }
+
+      function ParentComponent() {
+        return React.createElement(
+          RenderPropComponent,
+          null,
+          () => {
+            function UnstableNestedComponent() {
+              return React.createElement("div", null);
+            }
+
+            return React.createElement(
+              "div",
+              null,
+              React.createElement(UnstableNestedComponent, null)
+            );
+          }
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE}]
+    },
+    {
+      code: `
+      function ComponentForProps(props) {
+        return <div />;
+      }
+
+      function ParentComponent() {
+        return (
+          <ComponentForProps notPrefixedWithRender={() => <div />} />
+        );
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE_COMPONENT_AS_PROPS}]
+    },
+    {
+      code: `
+      function ComponentForProps(props) {
+        return React.createElement("div", null);
+      }
+
+      function ParentComponent() {
+        return React.createElement(ComponentForProps, {
+          notPrefixedWithRender: () => React.createElement("div", null)
+        });
+      }
+      `,
+      errors: [{message: ERROR_MESSAGE_COMPONENT_AS_PROPS}]
+    }
+  ]
+});