From 5b1ba6632fcfd01d120cbcc282168a3a535ca00d Mon Sep 17 00:00:00 2001
From: Zzzen <callmetsing@gmail.com>
Date: Mon, 3 Jan 2022 23:53:08 +0800
Subject: [PATCH] fix: add `this` to implicit global variables

---
 .../tests/eslint-rules/no-undef.test.ts       | 12 +++++++++-
 .../src/referencer/Referencer.ts              |  7 ++++++
 .../src/referencer/TypeVisitor.ts             | 11 +--------
 packages/typescript-estree/src/convert.ts     |  9 -------
 packages/typescript-estree/src/node-utils.ts  | 24 -------------------
 5 files changed, 19 insertions(+), 44 deletions(-)

diff --git a/packages/eslint-plugin/tests/eslint-rules/no-undef.test.ts b/packages/eslint-plugin/tests/eslint-rules/no-undef.test.ts
index 53dd3be8d0d6..392725d653f2 100644
--- a/packages/eslint-plugin/tests/eslint-rules/no-undef.test.ts
+++ b/packages/eslint-plugin/tests/eslint-rules/no-undef.test.ts
@@ -249,13 +249,23 @@ class Foo {}
 export type AppState = typeof import('./src/store/reducers').default;
     `,
     `
+let self: typeof this;
+let foo: typeof this.foo;
 const obj = {
   foo: '',
   bar() {
     let self: typeof this;
-    let foo: typeof this.foo;
   },
 };
+
+class C {
+  foo() {
+    let self: typeof this;
+  }
+  bar = () => {
+    let self: typeof this;
+  }
+}
     `,
   ],
   invalid: [
diff --git a/packages/scope-manager/src/referencer/Referencer.ts b/packages/scope-manager/src/referencer/Referencer.ts
index 10273bfb6b35..14f16aa7f268 100644
--- a/packages/scope-manager/src/referencer/Referencer.ts
+++ b/packages/scope-manager/src/referencer/Referencer.ts
@@ -98,6 +98,13 @@ class Referencer extends Visitor {
       isTypeVariable: true,
       isValueVariable: false,
     });
+
+    // prevent `no-undef` from reporting `typeof this`
+    globalScope.defineImplicitVariable('this', {
+      eslintImplicitGlobalSetting: 'readonly',
+      isTypeVariable: false,
+      isValueVariable: true,
+    });
   }
 
   /**
diff --git a/packages/scope-manager/src/referencer/TypeVisitor.ts b/packages/scope-manager/src/referencer/TypeVisitor.ts
index bbfbab230202..e9abb40f4f42 100644
--- a/packages/scope-manager/src/referencer/TypeVisitor.ts
+++ b/packages/scope-manager/src/referencer/TypeVisitor.ts
@@ -258,20 +258,11 @@ class TypeVisitor extends Visitor {
   protected TSTypeQuery(node: TSESTree.TSTypeQuery): void {
     if (node.exprName.type === AST_NODE_TYPES.Identifier) {
       this.#referencer.currentScope().referenceValue(node.exprName);
-    } else if (
-      (node.exprName.type as unknown) === AST_NODE_TYPES.ThisExpression
-    ) {
-      // technically exprName is either Identifier or QualifiedName, but eslint does not recognize `typeof this`,
-      // so we have translated it to ThisExpression.
-      return;
     } else {
       let expr = node.exprName.left;
-      while (expr.type === TSESTree.AST_NODE_TYPES.TSQualifiedName) {
+      while (expr.type !== AST_NODE_TYPES.Identifier) {
         expr = expr.left;
       }
-      if ((expr.type as unknown) === AST_NODE_TYPES.ThisExpression) {
-        return;
-      }
       this.#referencer.currentScope().referenceValue(expr);
     }
   }
diff --git a/packages/typescript-estree/src/convert.ts b/packages/typescript-estree/src/convert.ts
index 99453a9f4093..f0fb7d3cf58b 100644
--- a/packages/typescript-estree/src/convert.ts
+++ b/packages/typescript-estree/src/convert.ts
@@ -20,7 +20,6 @@ import {
   isComputedProperty,
   isESTreeClassMember,
   isOptional,
-  isThisInTypeQuery,
   TSError,
   unescapeStringLiteralText,
 } from './node-utils';
@@ -788,14 +787,6 @@ export class Converter {
       }
 
       case SyntaxKind.Identifier: {
-        if (isThisInTypeQuery(node)) {
-          return this.createNode<TSESTree.ThisExpression>(
-            node as unknown as ts.ThisExpression,
-            {
-              type: AST_NODE_TYPES.ThisExpression,
-            },
-          );
-        }
         return this.createNode<TSESTree.Identifier>(node, {
           type: AST_NODE_TYPES.Identifier,
           name: node.text,
diff --git a/packages/typescript-estree/src/node-utils.ts b/packages/typescript-estree/src/node-utils.ts
index 8bca0930cb7e..d8182aa5655e 100644
--- a/packages/typescript-estree/src/node-utils.ts
+++ b/packages/typescript-estree/src/node-utils.ts
@@ -663,27 +663,3 @@ export function firstDefined<T, U>(
   }
   return undefined;
 }
-
-export function identifierIsThisKeyword(id: ts.Identifier): boolean {
-  return id.originalKeywordKind === SyntaxKind.ThisKeyword;
-}
-
-export function isThisIdentifier(node: ts.Node | undefined): boolean {
-  return (
-    !!node &&
-    node.kind === SyntaxKind.Identifier &&
-    identifierIsThisKeyword(node as ts.Identifier)
-  );
-}
-
-export function isThisInTypeQuery(node: ts.Node): boolean {
-  if (!isThisIdentifier(node)) {
-    return false;
-  }
-
-  while (ts.isQualifiedName(node.parent) && node.parent.left === node) {
-    node = node.parent;
-  }
-
-  return node.parent.kind === SyntaxKind.TypeQuery;
-}