From 8b8af5fd7d3dee21a0a38f75c7d13d53ae7345cd Mon Sep 17 00:00:00 2001
From: Oleksandr T <oleksandr.tarasiuk@outlook.com>
Date: Tue, 26 Sep 2023 22:00:31 +0300
Subject: [PATCH] fix(55796): forbid this tag for arrow functions

---
 src/compiler/checker.ts                       | 11 ++++++++
 tests/baselines/reference/thisTag3.errors.txt | 21 +++++++++++++++
 tests/baselines/reference/thisTag3.symbols    | 21 +++++++++++++++
 tests/baselines/reference/thisTag3.types      | 27 +++++++++++++++++++
 tests/cases/conformance/jsdoc/thisTag3.ts     | 16 +++++++++++
 5 files changed, 96 insertions(+)
 create mode 100644 tests/baselines/reference/thisTag3.errors.txt
 create mode 100644 tests/baselines/reference/thisTag3.symbols
 create mode 100644 tests/baselines/reference/thisTag3.types
 create mode 100644 tests/cases/conformance/jsdoc/thisTag3.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 1748e660e9259..1bb754b696522 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -775,6 +775,7 @@ import {
     JSDocSatisfiesTag,
     JSDocSignature,
     JSDocTemplateTag,
+    JSDocThisTag,
     JSDocTypeAssertion,
     JSDocTypedefTag,
     JSDocTypeExpression,
@@ -40989,6 +40990,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
     function checkJSDocParameterTag(node: JSDocParameterTag) {
         checkSourceElement(node.typeExpression);
     }
+
     function checkJSDocPropertyTag(node: JSDocPropertyTag) {
         checkSourceElement(node.typeExpression);
     }
@@ -41004,6 +41006,13 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         }
     }
 
+    function checkJSDocThisTag(node: JSDocThisTag) {
+        const host = getEffectiveJSDocHost(node);
+        if (host && isArrowFunction(host)) {
+            error(node.tagName, Diagnostics.An_arrow_function_cannot_have_a_this_parameter);
+        }
+    }
+
     function checkJSDocImplementsTag(node: JSDocImplementsTag): void {
         const classLike = getEffectiveJSDocHost(node);
         if (!classLike || !isClassDeclaration(classLike) && !isClassExpression(classLike)) {
@@ -45724,6 +45733,8 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 return checkJSDocAccessibilityModifiers(node as JSDocPublicTag | JSDocProtectedTag | JSDocPrivateTag);
             case SyntaxKind.JSDocSatisfiesTag:
                 return checkJSDocSatisfiesTag(node as JSDocSatisfiesTag);
+            case SyntaxKind.JSDocThisTag:
+                return checkJSDocThisTag(node as JSDocThisTag);
             case SyntaxKind.IndexedAccessType:
                 return checkIndexedAccessType(node as IndexedAccessTypeNode);
             case SyntaxKind.MappedType:
diff --git a/tests/baselines/reference/thisTag3.errors.txt b/tests/baselines/reference/thisTag3.errors.txt
new file mode 100644
index 0000000000000..81623b16cefa9
--- /dev/null
+++ b/tests/baselines/reference/thisTag3.errors.txt
@@ -0,0 +1,21 @@
+/a.js(7,9): error TS2730: An arrow function cannot have a 'this' parameter.
+/a.js(10,21): error TS2339: Property 'fn' does not exist on type 'C'.
+
+
+==== /a.js (2 errors) ====
+    /**
+     * @typedef {{fn(a: string): void}} T
+     */
+    
+    class C {
+        /**
+         * @this {T}
+            ~~~~
+!!! error TS2730: An arrow function cannot have a 'this' parameter.
+         * @param {string} a
+         */
+        p = (a) => this.fn("" + a);
+                        ~~
+!!! error TS2339: Property 'fn' does not exist on type 'C'.
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/thisTag3.symbols b/tests/baselines/reference/thisTag3.symbols
new file mode 100644
index 0000000000000..9fbc0b5aabf53
--- /dev/null
+++ b/tests/baselines/reference/thisTag3.symbols
@@ -0,0 +1,21 @@
+//// [tests/cases/conformance/jsdoc/thisTag3.ts] ////
+
+=== /a.js ===
+/**
+ * @typedef {{fn(a: string): void}} T
+ */
+
+class C {
+>C : Symbol(C, Decl(a.js, 0, 0))
+
+    /**
+     * @this {T}
+     * @param {string} a
+     */
+    p = (a) => this.fn("" + a);
+>p : Symbol(C.p, Decl(a.js, 4, 9))
+>a : Symbol(a, Decl(a.js, 9, 9))
+>this : Symbol(C, Decl(a.js, 0, 0))
+>a : Symbol(a, Decl(a.js, 9, 9))
+}
+
diff --git a/tests/baselines/reference/thisTag3.types b/tests/baselines/reference/thisTag3.types
new file mode 100644
index 0000000000000..08334eacaef0f
--- /dev/null
+++ b/tests/baselines/reference/thisTag3.types
@@ -0,0 +1,27 @@
+//// [tests/cases/conformance/jsdoc/thisTag3.ts] ////
+
+=== /a.js ===
+/**
+ * @typedef {{fn(a: string): void}} T
+ */
+
+class C {
+>C : C
+
+    /**
+     * @this {T}
+     * @param {string} a
+     */
+    p = (a) => this.fn("" + a);
+>p : (this: T, a: string) => any
+>(a) => this.fn("" + a) : (this: T, a: string) => any
+>a : string
+>this.fn("" + a) : any
+>this.fn : any
+>this : this
+>fn : any
+>"" + a : string
+>"" : ""
+>a : string
+}
+
diff --git a/tests/cases/conformance/jsdoc/thisTag3.ts b/tests/cases/conformance/jsdoc/thisTag3.ts
new file mode 100644
index 0000000000000..1db6d34b21c95
--- /dev/null
+++ b/tests/cases/conformance/jsdoc/thisTag3.ts
@@ -0,0 +1,16 @@
+// @allowJs: true
+// @checkJs: true
+// @noEmit: true
+// @filename: /a.js
+
+/**
+ * @typedef {{fn(a: string): void}} T
+ */
+
+class C {
+    /**
+     * @this {T}
+     * @param {string} a
+     */
+    p = (a) => this.fn("" + a);
+}