angular - Angular2 2.0.0 Component Unit Test causes error: Bootstrap at least one component before injecting Router

Question

Looking at previous similar questions, it doesn't seem that there was ever a clear answer for this.

Here's what's happening. I'm building an angular2 app using the angular-cli tool (beta 16 running, with angular 2.0.1 and router 3.0.1.

When I run "ng test" all my tests pass, expect my app.component. (ng serve is working fine etc)

Here's some code:

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';

import { AppComponent } from './app.component';
import { HomeComponent } from './home/home.component';
import { HealthComponent } from './health/health.component';
import { MonitorModule } from './monitor/monitor.module';
import { PlanComponent } from './plan/plan.component';
import { ConfigureComponent } from './configure/configure.component';
import { DashboardComponent } from './dashboard/dashboard.component';
import { TroubleshootComponent } from './troubleshoot/troubleshoot.component';
import { HeaderComponent } from './ui/header/header.component';
import { OnboardingModule } from './onboarding/onboarding.module';
import { routing, appRoutingProviders }  from './app.routing';

@NgModule({
  imports: [
    BrowserModule,
    FormsModule,
    HttpModule,
    routing,
    MonitorModule,
    OnboardingModule
  ],
  declarations: [
    AppComponent,
    HomeComponent,
    HealthComponent,
    PlanComponent,
    ConfigureComponent,
    DashboardComponent,
    TroubleshootComponent,
    HeaderComponent
  ],
  providers: [
    appRoutingProviders
  ],
  bootstrap: [AppComponent]
})
export class AppModule {
}

app.component.ts

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html'
})
export class AppComponent  {

}

app.component.spec.ts

/* tslint:disable:no-unused-variable */

import { TestBed, async } from '@angular/core/testing';
import { APP_BASE_HREF } from '@angular/common';
import { routing, appRoutingProviders }  from './app.routing';
import { AppComponent } from './app.component';
import { HomeComponent } from './home/home.component';
import { HeaderComponent } from './ui/header/header.component';
import { HealthComponent } from './health/health.component';
import { PlanComponent } from './plan/plan.component';
import { ConfigureComponent } from './configure/configure.component';
import { DashboardComponent } from './dashboard/dashboard.component';
import { TroubleshootComponent } from './troubleshoot/troubleshoot.component';

describe('App: Ng2Test2', () => {
  beforeEach(() => {
    TestBed.configureTestingModule({
      declarations: [
        AppComponent,
        HeaderComponent,
        HomeComponent,
        HealthComponent,
        PlanComponent,
        ConfigureComponent,
        DashboardComponent,
        TroubleshootComponent
      ],
      imports: [
        routing
      ],
      providers: [
        appRoutingProviders,
        { provide: APP_BASE_HREF, useValue : '/' }
      ]
    });
  });

  it('should create the app', async(() => {
    let fixture = TestBed.createComponent(AppComponent);
    let app = fixture.debugElement.componentInstance;
    expect(app).toBeTruthy();
  }));
});

app.component.html

  <app-header></app-header>

  <router-outlet></router-outlet>

Finally, here's the error I'm getting when I run "ng test":

App: Ng2Test2 should create the app FAILED
    Failed: Error in ./AppComponent class AppComponent - inline template:2:2 caused by: Bootstrap at least one component before injecting Router.
    Error: Bootstrap at least one component before injecting Router.
        at setupRouter (webpack:///Users/jtaylor/Projects/hmng-angular/hmng-ng2/~/@angular/router/src/router_module.js:190:0 <- src/test.ts:29132:15)

I've tried a ton of different things to prevent this error, but can't get this one to stop firing!

Any thoughts on this?

EDIT: I tracked it down to this component, where I use router in my constructor:

header.component.ts

import { Component, OnInit } from '@angular/core';
import { Router, ActivatedRoute, NavigationEnd } from '@angular/router';
import { AppComponent } from '../../app.component';

@Component({
  selector: 'app-header',
  templateUrl: './header.component.html'
})
export class HeaderComponent implements OnInit {

  section: any;
  // router: Router;
  // activateRoute: ActivatedRoute;

  constructor(
    public router: Router,
    public activatedRoute: ActivatedRoute
  ) {}

  ngOnInit() {
    this.router.events.subscribe(e => {
      if (e instanceof NavigationEnd) {
        this.setActiveNavTab(e.url.replace(/^/([^/]*).*$/, '$1'));
      }
    });
  }

  setActiveNavTab(section: string) {
    this.section = section;
  }

}

So, how can I bootstrap a component before that constructor with the unit test?

Answer 1

It's because you are trying to use the RouterModule for the test. Instead you should use the RouterTestingModule and add your routes with RouterTestingModule.withRoutes

import { RouterTestingModule } from '@angular/router/testing';

imports: [
  // routing
  RouterTestingModule.withRoutes(APP_ROUTES)
]