Isolated tests

It is often useful to test complex components without rendering them. To see how it can be done, let's write a test for the following component:

@Component({moduleId: module.id, templateUrl: 'compose.html'})
class ComposeCmp {
  form = new FormGroup({
    title: new FormControl('', Validators.required),
    body: new FormControl('')
  });

  constructor(private route: ActivatedRoute,
              private currentTime: CurrentTime,
              private actions: Actions) {}

  onSubmit() {
    const routerStateRoot = this.route.snapshot.root;
    const conversationRoute = routerStateRoot.firstChild;
    const conversationId = +conversationRoute.params['id'];

    const payload = Object.assign({},
      this.form.value,
      {createdAt: this.currentTime()});

    this.actions.next({
      type: 'reply',
      conversationId: conversationId,
      payload: payload
    });
  }
}

Here's the compose.html file:

<form...