test: add unit tests for example

Add unit tests for the InjectionToken example in packages/examples/injection-token/src/main.ts.
Tests cover basic token injection, error cases, factory providers, and TestBed integration.

Fixes #TODO

Author: MeAkib

adev/shared-docs/components/viewers/docs-viewer/docs-viewer.component.spec.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import {ComponentFixture, TestBed} from '@angular/core/testing';
+import {TestBed} from '@angular/core/testing';
 import {By} from '@angular/platform-browser';
 import {provideRouter} from '@angular/router';
 import {ExampleViewerContentLoader} from '../../../interfaces';

packages/examples/injection-token/src/main.ts

@@ -6,18 +6,17 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-// TODO: Add unit tests for this file.
 /* eslint-disable @angular-eslint/no-output-native */
 // #docregion
 import {Injector, InjectionToken} from '@angular/core';
 
-interface MyInterface {
+export interface MyInterface {
   someProperty: string;
 }
 
 // #docregion InjectionToken
 
-const TOKEN = new InjectionToken<MyInterface>('SomeToken');
+export const TOKEN = new InjectionToken<MyInterface>('SomeToken');
 
 // Setting up the provider using the same token instance
 const providers = [

packages/examples/injection-token/src/test/BUILD.bazel

@@ -0,0 +1,34 @@
+load("//tools:defaults.bzl", "angular_jasmine_test", "ng_web_test_suite", "ts_project")
+
+package(default_visibility = ["//visibility:public"])
+
+ts_project(
+    name = "test_lib",
+    testonly = True,
+    srcs = glob(["**/*.spec.ts"]),
+    deps = [
+        "//packages/core",
+        "//packages/core/testing",
+    ],
+)
+
+angular_jasmine_test(
+    name = "test",
+    data = [
+        ":test_lib",
+    ],
+)
+
+ng_web_test_suite(
+    name = "test_web",
+    deps = [
+        ":test_lib",
+    ],
+)
+
+filegroup(
+    name = "files_for_docgen",
+    srcs = glob([
+        "**/*.ts",
+    ]),
+)

packages/examples/injection-token/src/test/main.spec.ts

@@ -0,0 +1,78 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.dev/license
+ */
+
+import {TestBed} from '@angular/core/testing';
+import {InjectionToken, Injector} from '@angular/core';
+import {MyInterface, TOKEN} from '../main';
+
+describe('InjectionToken Example', () => {
+  it('should create and inject token with correct type', () => {
+    const providers = [{provide: TOKEN, useValue: {someProperty: 'exampleValue'}}];
+    const injector = Injector.create({providers});
+    const myInterface = injector.get(TOKEN);
+
+    expect(myInterface).toBeDefined();
+    expect(myInterface.someProperty).toBe('exampleValue');
+    expect(myInterface.someProperty).toEqual(jasmine.any(String));
+  });
+
+  it('should throw error when token is not provided', () => {
+    const injector = Injector.create({providers: []});
+
+    expect(() => {
+      injector.get(TOKEN);
+    }).toThrowError(/NG0201.*No provider found for.*InjectionToken SomeToken/);
+  });
+
+  it('should return null when token is optional and not provided', () => {
+    const injector = Injector.create({providers: []});
+
+    const result = injector.get(TOKEN, null);
+    expect(result).toBeNull();
+  });
+
+  it('should work with multiple providers', () => {
+    const TOKEN1 = new InjectionToken<string>('Token1');
+    const TOKEN2 = new InjectionToken<number>('Token2');
+
+    const providers = [
+      {provide: TOKEN1, useValue: 'string value'},
+      {provide: TOKEN2, useValue: 42},
+    ];
+
+    const injector = Injector.create({providers});
+
+    expect(injector.get(TOKEN1)).toBe('string value');
+    expect(injector.get(TOKEN2)).toBe(42);
+  });
+
+  it('should use factory provider', () => {
+    const FACTORY_TOKEN = new InjectionToken<MyInterface>('FactoryToken');
+
+    const providers = [
+      {
+        provide: FACTORY_TOKEN,
+        useFactory: () => ({someProperty: 'from factory'}),
+      },
+    ];
+
+    const injector = Injector.create({providers});
+    const result = injector.get(FACTORY_TOKEN);
+
+    expect(result.someProperty).toBe('from factory');
+  });
+
+  it('should work with TestBed', () => {
+    TestBed.configureTestingModule({
+      providers: [{provide: TOKEN, useValue: {someProperty: 'testBed value'}}],
+    });
+
+    const result = TestBed.inject(TOKEN);
+    expect(result.someProperty).toBe('testBed value');
+  });
+});