1. 确认导入的依赖是否正确，并在 TestBed 的配置中添加 RouterModule:

import { TestBed, async } from '@angular/core/testing'; import { RouterModule } from '@angular/router'; import { RouterTestingModule } from "@angular/router/testing"; import { AppComponent } from './app.component';

describe('AppComponent', () => { beforeEach(async(() => { TestBed.configureTestingModule({ imports: [ RouterTestingModule, RouterModule ], declarations: [ AppComponent ], }).compileComponents(); })); });

2. 在测试之前手动导入 AppRoutingModule，并添加一个 NgModuleRef 的 mocked 实例，以使测试通过:

import { Component, NgModule } from '@angular/core'; import { RouterModule } from '@angular/router'; import { AppRoutingModule } from './app-routing.module';

@Component({ selector: 'app-test-cmp', template: '', }) export class TestComponent {}

@NgModule({ imports: [AppRoutingModule, RouterModule], declarations: [TestComponent], exports: [TestComponent], }) export class TestModule {}

describe('AppComponent', () => { beforeEach(async(() => { TestBed.configureTestingModule({ imports: [RouterTestingModule.withRoutes([]), TestModule], declarations: [AppComponent], }) .overrideComponent(AppComponent, { set: { providers: [{ provide: NgModuleRef, useValue: {} }], }, }) .compileComponents(); })); });

3. 在 TestBed 配置中将 RouterTestingModule 的 imports 与 AppRoutingModule 合并，以使测试通过:

TestBed.configureTestingModule({ imports: [RouterTestingModule.withRoutes(routes), AppRoutingModule], declarations: [AppComponent, HomeComponent, AboutComponent], });

通过以上步骤进行配置后，用 Karma 运行测试即可。