xphong xphong - 1 month ago 54
Javascript Question

Angular 2 Final Release Router Unit Test

How do I unit test routers in Angular version 2.0.0 with karma and jasmine?

Here's what my old unit test looks like in version 2.0.0-beta.14



import {
it,
inject,
injectAsync,
beforeEach,
beforeEachProviders,
TestComponentBuilder
} from 'angular2/testing';

import { RootRouter } from 'angular2/src/router/router';
import { Location, RouteParams, Router, RouteRegistry, ROUTER_PRIMARY_COMPONENT } from 'angular2/router';
import { SpyLocation } from 'angular2/src/mock/location_mock';
import { provide } from 'angular2/core';

import { App } from './app';

describe('Router', () => {

let location, router;

beforeEachProviders(() => [
RouteRegistry,
provide(Location, {useClass: SpyLocation}),
provide(Router, {useClass: RootRouter}),
provide(ROUTER_PRIMARY_COMPONENT, {useValue: App})
]);

beforeEach(inject([Router, Location], (_router, _location) => {
router = _router;
location = _location;
}));

it('Should be able to navigate to Home', done => {
router.navigate(['Home']).then(() => {
expect(location.path()).toBe('');
done();
}).catch(e => done.fail(e));
});

});




Answer

For testing we now create a testing module using TestBed. We can use he TestBed#configureTestingModule and pass a metadata object to it the same way we would pass to @NgModule

beforeEach(() => {
  TestBed.configureTestingModule({
    imports: [ /* modules to import */ ],
    providers: [ /* add providers */ ],
    declarations: [ /* components, directives, and pipes */ ]
  });
});

For routing, instead of using the normal RouterModule, we would instead use RouterTestingModule. This sets up the Router and Location, so you don't need to yourself. You can also pass routes to it, by calling RouterTestingModule.withRoutes(Routes)

TestBed.configureTestingModule({
  imports: [
    RouterTestingModule.withRoutes([
      { path: 'home', component: DummyComponent }
    ])
  ]
})

To get the Location and Router in the test, the same thing works, as in your example.

let router, location;

beforeEach(() => {
  TestBed...
});

beforeEach(inject([Router, Location], (_router: Router, _location: Location) => {
  router = _router;
  location = _location;
}));

You could also inject into each test as necessary

it('should go home',
    async(inject([Router, Location], (router: Router, location: Location) => {
})));

The async above is used like done except we don't need to explicitly call done. Angular will actually do that for us after call asynchronous tasks are complete.

Another way to get the providers is from the test bed.

let location, router;

beforeEach(() => {
  TestBed.configureTestingModule({
    imports: [RouterTestingModule.withRoutes([
      { path: 'home', component: DummyComponent }
    ])],
  });
  let injector = getTestBed();
  location = injector.get(Location);
  router = injector.get(Router);
});

Here's a complete test, refactoring your example

import { Component } from '@angular/core';
import { Location } from '@angular/common';
import { Router } from '@angular/router';
import { RouterTestingModule } from '@angular/router/testing';
import { fakeAsync, async, inject, TestBed, getTestBed } from '@angular/core/testing';
import { By } from '@angular/platform-browser';

@Component({
  template: `
    <router-outlet></router-outlet>
  `
})
class RoutingComponent { }

@Component({
  template: ''
})
class DummyComponent { }

describe('component: RoutingComponent', () => {
  let location, router;

  beforeEach(() => {
    TestBed.configureTestingModule({
      imports: [RouterTestingModule.withRoutes([
        { path: 'home', component: DummyComponent }
      ])],
      declarations: [RoutingComponent, DummyComponent]
    });
  });

  beforeEach(inject([Router, Location], (_router: Router, _location: Location) => {
    location = _location;
    router = _router;
  }));

  it('should go home', async(() => {
    let fixture = TestBed.createComponent(RoutingComponent);
    fixture.detectChanges();
    router.navigate(['/home']).then(() => {
      expect(location.path()).toBe('/home');
      console.log('after expect');
    });
  }));
});
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