fix(51868): this within function typed as any when annotated with JSDoc

src/compiler/checker.ts

@@ -28436,20 +28436,15 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         }
     }
 
-    function getTypeForThisExpressionFromJSDoc(node: Node) {
-        const jsdocType = getJSDocType(node);
-        if (jsdocType && jsdocType.kind === SyntaxKind.JSDocFunctionType) {
-            const jsDocFunctionType = jsdocType as JSDocFunctionType;
-            if (jsDocFunctionType.parameters.length > 0 &&
-                jsDocFunctionType.parameters[0].name &&
-                (jsDocFunctionType.parameters[0].name as Identifier).escapedText === InternalSymbolName.This) {
-                return getTypeFromTypeNode(jsDocFunctionType.parameters[0].type!);
-            }
-        }
+    function getTypeForThisExpressionFromJSDoc(node: SignatureDeclaration) {
         const thisTag = getJSDocThisTag(node);
         if (thisTag && thisTag.typeExpression) {
             return getTypeFromTypeNode(thisTag.typeExpression);
         }
+        const signature = getSignatureOfTypeTag(node);
+        if (signature) {
+            return getThisTypeOfSignature(signature);
+        }
     }
 
     function isInConstructorArgumentInitializer(node: Node, constructorDecl: Node): boolean {

tests/baselines/reference/jsdocThisType.errors.txt

@@ -0,0 +1,58 @@
+/a.js(3,10): error TS2339: Property 'test' does not exist on type 'Foo'.
+/a.js(8,10): error TS2339: Property 'test' does not exist on type 'Foo'.
+/a.js(13,10): error TS2339: Property 'test' does not exist on type 'Foo'.
+/a.js(18,10): error TS2339: Property 'test' does not exist on type 'Foo'.
+/a.js(23,10): error TS2339: Property 'test' does not exist on type 'Foo'.
+/a.js(28,10): error TS2339: Property 'test' does not exist on type 'Foo'.
+
+
+==== /types.d.ts (0 errors) ====
+    export interface Foo {
+        foo: () => void;
+    }
+
+    export type M = (this: Foo) => void;
+
+==== /a.js (6 errors) ====
+    /** @type {import('./types').M} */
+    export const f1 = function() {
+        this.test();
+             ~~~~
+!!! error TS2339: Property 'test' does not exist on type 'Foo'.
+    }
+
+    /** @type {import('./types').M} */
+    export function f2() {
+        this.test();
+             ~~~~
+!!! error TS2339: Property 'test' does not exist on type 'Foo'.
+    }
+
+    /** @type {(this: import('./types').Foo) => void} */
+    export const f3 = function() {
+        this.test();
+             ~~~~
+!!! error TS2339: Property 'test' does not exist on type 'Foo'.
+    }
+
+    /** @type {(this: import('./types').Foo) => void} */
+    export function f4() {
+        this.test();
+             ~~~~
+!!! error TS2339: Property 'test' does not exist on type 'Foo'.
+    }
+
+    /** @type {function(this: import('./types').Foo): void} */
+    export const f5 = function() {
+        this.test();
+             ~~~~
+!!! error TS2339: Property 'test' does not exist on type 'Foo'.
+    }
+
+    /** @type {function(this: import('./types').Foo): void} */
+    export function f6() {
+        this.test();
+             ~~~~
+!!! error TS2339: Property 'test' does not exist on type 'Foo'.
+    }
+

tests/baselines/reference/jsdocThisType.symbols

@@ -0,0 +1,62 @@
+=== /types.d.ts ===
+export interface Foo {
+>Foo : Symbol(Foo, Decl(types.d.ts, 0, 0))
+
+    foo: () => void;
+>foo : Symbol(Foo.foo, Decl(types.d.ts, 0, 22))
+}
+
+export type M = (this: Foo) => void;
+>M : Symbol(M, Decl(types.d.ts, 2, 1))
+>this : Symbol(this, Decl(types.d.ts, 4, 17))
+>Foo : Symbol(Foo, Decl(types.d.ts, 0, 0))
+
+=== /a.js ===
+/** @type {import('./types').M} */
+export const f1 = function() {
+>f1 : Symbol(f1, Decl(a.js, 1, 12))
+
+    this.test();
+>this : Symbol(this, Decl(types.d.ts, 4, 17))
+}
+
+/** @type {import('./types').M} */
+export function f2() {
+>f2 : Symbol(f2, Decl(a.js, 3, 1))
+
+    this.test();
+>this : Symbol(Foo, Decl(types.d.ts, 0, 0))
+}
+
+/** @type {(this: import('./types').Foo) => void} */
+export const f3 = function() {
+>f3 : Symbol(f3, Decl(a.js, 11, 12))
+
+    this.test();
+>this : Symbol(this, Decl(a.js, 10, 12))
+}
+
+/** @type {(this: import('./types').Foo) => void} */
+export function f4() {
+>f4 : Symbol(f4, Decl(a.js, 13, 1))
+
+    this.test();
+>this : Symbol(Foo, Decl(types.d.ts, 0, 0))
+}
+
+/** @type {function(this: import('./types').Foo): void} */
+export const f5 = function() {
+>f5 : Symbol(f5, Decl(a.js, 21, 12))
+
+    this.test();
+>this : Symbol(this, Decl(a.js, 20, 20))
+}
+
+/** @type {function(this: import('./types').Foo): void} */
+export function f6() {
+>f6 : Symbol(f6, Decl(a.js, 23, 1))
+
+    this.test();
+>this : Symbol(Foo, Decl(types.d.ts, 0, 0))
+}
+

tests/baselines/reference/jsdocThisType.types

@@ -0,0 +1,80 @@
+=== /types.d.ts ===
+export interface Foo {
+    foo: () => void;
+>foo : () => void
+}
+
+export type M = (this: Foo) => void;
+>M : (this: Foo) => void
+>this : Foo
+
+=== /a.js ===
+/** @type {import('./types').M} */
+export const f1 = function() {
+>f1 : import("/types").M
+>function() {    this.test();} : (this: import("/types").Foo) => void
+
+    this.test();
+>this.test() : any
+>this.test : any
+>this : import("/types").Foo
+>test : any
+}
+
+/** @type {import('./types').M} */
+export function f2() {
+>f2 : (this: import("/types").Foo) => void
+
+    this.test();
+>this.test() : any
+>this.test : any
+>this : import("/types").Foo
+>test : any
+}
+
+/** @type {(this: import('./types').Foo) => void} */
+export const f3 = function() {
+>f3 : (this: import("/types").Foo) => void
+>function() {    this.test();} : (this: import("/types").Foo) => void
+
+    this.test();
+>this.test() : any
+>this.test : any
+>this : import("/types").Foo
+>test : any
+}
+
+/** @type {(this: import('./types').Foo) => void} */
+export function f4() {
+>f4 : (this: import('./types').Foo) => void
+
+    this.test();
+>this.test() : any
+>this.test : any
+>this : import("/types").Foo
+>test : any
+}
+
+/** @type {function(this: import('./types').Foo): void} */
+export const f5 = function() {
+>f5 : (this: import("/types").Foo) => void
+>function() {    this.test();} : (this: import("/types").Foo) => void
+
+    this.test();
+>this.test() : any
+>this.test : any
+>this : import("/types").Foo
+>test : any
+}
+
+/** @type {function(this: import('./types').Foo): void} */
+export function f6() {
+>f6 : (this: import('./types').Foo) => void
+
+    this.test();
+>this.test() : any
+>this.test : any
+>this : import("/types").Foo
+>test : any
+}
+

tests/cases/conformance/jsdoc/jsdocThisType.ts

@@ -0,0 +1,41 @@
+// @allowJs: true
+// @checkJs: true
+// @noEmit: true
+
+// @filename: /types.d.ts
+export interface Foo {
+    foo: () => void;
+}
+
+export type M = (this: Foo) => void;
+
+// @filename: /a.js
+/** @type {import('./types').M} */
+export const f1 = function() {
+    this.test();
+}
+
+/** @type {import('./types').M} */
+export function f2() {
+    this.test();
+}
+
+/** @type {(this: import('./types').Foo) => void} */
+export const f3 = function() {
+    this.test();
+}
+
+/** @type {(this: import('./types').Foo) => void} */
+export function f4() {
+    this.test();
+}
+
+/** @type {function(this: import('./types').Foo): void} */
+export const f5 = function() {
+    this.test();
+}
+
+/** @type {function(this: import('./types').Foo): void} */
+export function f6() {
+    this.test();
+}