fix(55796): JSDoc does not support @this when using an arrow function as method in class

src/compiler/checker.ts

@@ -780,6 +780,7 @@ import {
     JSDocSatisfiesTag,
     JSDocSignature,
     JSDocTemplateTag,
+    JSDocThisTag,
     JSDocTypeAssertion,
     JSDocTypedefTag,
     JSDocTypeExpression,
@@ -41240,6 +41241,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
     function checkJSDocParameterTag(node: JSDocParameterTag) {
         checkSourceElement(node.typeExpression);
     }
+
     function checkJSDocPropertyTag(node: JSDocPropertyTag) {
         checkSourceElement(node.typeExpression);
     }
@@ -41255,6 +41257,13 @@ 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)) {
@@ -45973,6 +45982,8 @@ 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:

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'.
+    }
+

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))
+}
+

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
+}
+

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);
+}