fix: overloading a function doesn't generate all of the signatures (#22569)

PR Close #22569

tools/public_api_guard/common/common.d.ts

@@ -303,7 +303,7 @@ export declare class NgLocaleLocalization extends NgLocalization {
     /** @deprecated */ protected deprecatedPluralFn: ((locale: string, value: string | number) => Plural) | null | undefined;
     protected locale: string;
     constructor(locale: string,
-        deprecatedPluralFn?: ((locale: string, value: string | number) => Plural) | null | undefined);
+        /** @deprecated */ deprecatedPluralFn?: ((locale: string, value: string | number) => Plural) | null | undefined);
     getPluralCategory(value: any, locale?: string): string;
 }
 

tools/public_api_guard/core/core.d.ts

@@ -449,6 +449,7 @@ export declare const HostListener: HostListenerDecorator;
 
 /** @experimental */
 export declare function inject<T>(token: Type<T> | InjectionToken<T>, notFoundValue?: undefined, flags?: InjectFlags): T;
+export declare function inject<T>(token: Type<T> | InjectionToken<T>, notFoundValue: T | null, flags?: InjectFlags): T | null;
 
 /** @stable */
 export declare const Inject: InjectDecorator;

tools/public_api_guard/core/testing.d.ts

@@ -156,3 +156,4 @@ export declare function withBody<T>(html: string, blockFn: T): T;
 
 /** @experimental */
 export declare function withModule(moduleDef: TestModuleMetadata): InjectSetupWrapper;
+export declare function withModule(moduleDef: TestModuleMetadata, fn: Function): () => any;

tools/public_api_guard/router/testing.d.ts

@@ -5,6 +5,7 @@ export declare class RouterTestingModule {
 
 /** @stable */
 export declare function setupTestingRouter(urlSerializer: UrlSerializer, contexts: ChildrenOutletContexts, location: Location, loader: NgModuleFactoryLoader, compiler: Compiler, injector: Injector, routes: Route[][], opts?: ExtraOptions, urlHandlingStrategy?: UrlHandlingStrategy): Router;
+export declare function setupTestingRouter(urlSerializer: UrlSerializer, contexts: ChildrenOutletContexts, location: Location, loader: NgModuleFactoryLoader, compiler: Compiler, injector: Injector, routes: Route[][], urlHandlingStrategy?: UrlHandlingStrategy): Router;
 
 /** @stable */
 export declare class SpyNgModuleFactoryLoader implements NgModuleFactoryLoader {

tools/ts-api-guardian/lib/serializer.ts

@@ -215,7 +215,15 @@ class ResolvedDeclarationEmitter {
       }
     }
 
-    let children = node.getChildren();
+    let children: ts.Node[] = [];
+    if (ts.isFunctionDeclaration(node)) {
+      // Used ts.isFunctionDeclaration instead of node.kind because this is a type guard
+      const symbol = this.typeChecker.getSymbolAtLocation(node.name);
+      symbol.declarations.forEach(x => children = children.concat(x.getChildren()));
+    } else {
+      children = node.getChildren();
+    }
+
     const sourceText = node.getSourceFile().text;
     if (children.length) {
       // Sort declarations under a class or an interface
@@ -252,7 +260,7 @@ class ResolvedDeclarationEmitter {
                                .join('');
 
       // Print stability annotation for fields
-      if (node.kind in memberDeclarationOrder) {
+      if (ts.isParameter(node) || node.kind in memberDeclarationOrder) {
         const trivia = sourceText.substr(node.pos, node.getLeadingTriviaWidth());
         const match = stabilityAnnotationPattern.exec(trivia);
         if (match) {

tools/ts-api-guardian/test/unit_test.ts

@@ -59,6 +59,24 @@ describe('unit test', () => {
     check({'file.d.ts': input}, expected);
   });
 
+  it('should support overloads functions', () => {
+    const input = `
+      export declare function group(steps: AnimationMetadata[], options?: AnimationOptions | null): AnimationGroupMetadata;
+
+      export declare function registerLocaleData(data: any, extraData?: any): void;
+      export declare function registerLocaleData(data: any, localeId?: string, extraData?: any): void;
+    `;
+
+    const expected = `
+      export declare function group(steps: AnimationMetadata[], options?: AnimationOptions | null): AnimationGroupMetadata;
+
+      export declare function registerLocaleData(data: any, extraData?: any): void;
+      export declare function registerLocaleData(data: any, localeId?: string, extraData?: any): void;
+    `;
+
+    check({'file.d.ts': input}, expected);
+  });
+
   it('should ignore private props', () => {
     const input = `
       export declare class A {