Angular执行测试报错: 'router-outlet' is not a known element

Love The Way You Lie 2022-04-11 13:18 472阅读 0赞

### 本机环境： ###

$ ng --version
    Angular CLI: 7.1.1
    Node: 10.11.0
    OS: darwin x64
    Angular: 7.1.1
    ... animations, cli, common, compiler, compiler-cli, core, forms
    ... http, language-service, platform-browser
    ... platform-browser-dynamic, router
    
    Package                           Version
    -----------------------------------------------------------
    @angular-devkit/architect         0.10.6
    @angular-devkit/build-angular     0.10.6
    @angular-devkit/build-optimizer   0.10.6
    @angular-devkit/build-webpack     0.10.6
    @angular-devkit/core              7.0.6
    @angular-devkit/schematics        7.1.1
    @ngtools/webpack                  7.0.6
    @schematics/angular               7.1.1
    @schematics/update                0.11.1
    rxjs                              6.3.3
    typescript                        3.1.6
    webpack                           4.19.1

### 报错内容 ###

使用 `ng serve` 运行应用，通过访问 `http://localhost:4200`，运行正常，未见报错。

但是，执行 `ng test` 测试就报错，错误内容如下：

Chrome 72.0.3622 (Mac OS X 10.13.6) AppComponent should create the app FAILED
    	'router-outlet' is not a known element:
    	1. If 'router-outlet' is an Angular component, then verify that it is part of this module.
    	2. If 'router-outlet' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas' of this component to suppress this message. ("
    	
    	[ERROR ->]<router-outlet></router-outlet>
        ...

错误提示，执行测试用例创建 AppComponent 失败，应该是测试代码里没有引入路由模块。

### 解决办法 ###

来自github用户 @mokipedia 的解决办法：

For everyone else having this issue: in app.component.spec.ts
    
    import {
        RouterTestingModule} from '@angular/router/testing'
    
    add imports to TestBed
    
    beforeEach(() => {
         
        TestBed.configureTestingModule({
         
            declarations: [ AppComponent ], 
            imports: [ RouterTestingModule ] 
        })
    })

在测试用例文件`app.component.spec.ts`的`beforeEach`部分引入模块 `RouterTestingModule`。

### 完整代码 ###

文件 `app.component.spec.ts` 完整代码如下：

// app.component.spec.ts
    import {
         TestBed, async } from '@angular/core/testing';
    import {
         AppComponent } from './app.component';
    import {
         RouterTestingModule } from '@angular/router/testing'
    import {
         HttpClientTestingModule } from '@angular/common/http/testing';
    import {
         MessagesComponent } from './pages/messages/messages.component';
    import {
         HeroSearchComponent } from './pages/hero-search/hero-search.component';
    
    describe('AppComponent', () => {
        
      beforeEach(async(() => {
        
        TestBed.configureTestingModule({
        
          declarations: [
            AppComponent, MessagesComponent, HeroSearchComponent
          ],
          imports: [ 
            // fix errors:  'router-outlet' is not a known element
            RouterTestingModule,
            HttpClientTestingModule, 
          ] 
        }).compileComponents();
      }));
    
      it('should create the app', async(() => {
        
        const fixture = TestBed.createComponent(AppComponent);
        const app = fixture.debugElement.componentInstance;
        expect(app).toBeTruthy();
      }));
    });