使用 Karma 进行测试 - 无法绑定到“routerLink”，因为它不是

Question

我刚开始在 Angular 6 应用程序中使用 Karma/Jasmine 进行测试，并且需要一些帮助来解决我最常见的故障之一。

就是我的模板中“RouterLink”的使用和配置。我运行应用程序没有错误，但在运行测试时，我收到错误：

Can't bind to 'routerLink' since it isn't a known property of 'a'.

我无法正确配置我的规范文件。关于如何修复配置以在运行测试时修复该错误有什么想法吗？我不确定这是否是我的 app.module 文件、组件或测试文件的问题。

import { NavigationComponent } from '../navigation/navigation.component';
import { EditMonitoringPointComponent } from './edit-monitoring-point.component';
import { FormsModule, NgModel } from '@angular/forms';
import { RouterLink, RouterModule } from '@angular/router';
import { NgModule } from '@angular/core';

describe('EditMonitoringPointComponent', () => {
  let component: EditMonitoringPointComponent;
  let fixture: ComponentFixture<EditMonitoringPointComponent>;

  beforeEach(async(() => {
    TestBed.configureTestingModule({
      imports: [ FormsModule],
      declarations: [ EditMonitoringPointComponent, NavigationComponent],
      providers: [ RouterModule, RouterLink],
      // directives: [ROUTER_DIRECTIVES]

    })
    .compileComponents();
  }));

  beforeEach(() => {
    fixture = TestBed.createComponent(EditMonitoringPointComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });

  it('should create', () => {
    expect(component).toBeTruthy();
  });
});

这是它捕获的 html 中的行：

<a [routerLink]="['/sites', current_mp.siteId]" ><i class='fa fa-ban'></i> Cancel</a>

我的组件看起来像：

import { ActivatedRoute, ParamMap, Router, RouterModule, RouterLink } from '@angular/router';
import { SiteService } from '../../services/site.service'
import { MonitoringPointService } from '../../services/monitoring-point.service'
import { AuthService } from '../../services/auth.service'
import { DeviceService } from '../../services/device.service';
import { MatDialog, MatDialogRef, MAT_DIALOG_DATA } from '@angular/material/dialog';

@Component({
  selector: 'app-edit-monitoring-point',
  templateUrl: './edit-monitoring-point.component.html',
  styleUrls: ['./edit-monitoring-point.component.css']
})

export class EditMonitoringPointComponent implements OnInit {
//declare variables
}

constructor(private router: Router, private monitoringPointService: MonitoringPointService, public dialog: MatDialog, private deviceService: DeviceService, public siteService: SiteService, private route: ActivatedRoute, private SiteService: SiteService, private authService: AuthService) { }

ngOnInit() {
...
}

app.module.ts

import { NgModule } from '@angular/core';
import { 
RouterModule}  from '@angular/router';
import { AppRoutingModule, routingComponents } from './app-routing.module';
import { FormsModule } from '@angular/forms';
import { HttpClientModule, HTTP_INTERCEPTORS } from '@angular/common/http';
import { AppComponent } from './app.component';

@NgModule({
  declarations: [
    AppComponent,
    routingComponents],
  imports: [
    RouterModule,
    BrowserModule,
    AppRoutingModule,
    FormsModule,
    HttpClientModule,],
  providers: [
      {provide: HTTP_INTERCEPTORS,
      useClass: UnauthorizedResponseInterceptor,
      multi: true}]
})
export class AppModule { }
platformBrowserDynamic().bootstrapModule(AppModule);

Thank you so much!

Answer 1

您应该将 RouterTestingModule 添加到规范文件中的导入中。 这应该允许 Angular 识别你的 routerLink 指令。 同时清除提供者数组。

更多信息请参考本教程： https://codecraft.tv/courses/angular/unit-testing/routing/

此外，如果对“测试”组件内的路由不感兴趣，您可以简单地将 NO_ERROR_SCHEMA 添加到您的configureTestingModule 方法中。

schemas: [NO_ERRORS_SCHEMA]

Answer 2

对于像我一样偶然发现这个问题的人： 虽然 RouterTestingModule 仍然有效，但自从最近的 Angular 更新以来，它现在被标记为已弃用。 新的解决方案似乎是：

对于非独立组件，请将以下“RouterModule.forRoot([])”添加到规范文件中的导入中，即

await TestBed.configureTestingModule({
      imports: [RouterModule.forRoot([])],
      declarations: [MyNewNonStandaloneComponent]
})
.compileComponents();

或者对于独立组件，在规范文件中添加“provideRouter([])”作为提供程序，即

await TestBed.configureTestingModule({
      providers: [provideRouter([])],
      declarations: [MyNewStandaloneComponent]      
})
.compileComponents();