test: comments from issue #270

tests/issue-270/test.spec.ts

@@ -0,0 +1,58 @@
+import { Component, Injectable } from '@angular/core';
+import { TestBed } from '@angular/core/testing';
+import { MockProvider, MockRender } from 'ng-mocks';
+import { Subject } from 'rxjs';
+
+export const EMPTY = new Subject<any>();
+EMPTY.complete();
+
+@Injectable()
+class TargetService {
+  public stream$ = EMPTY;
+}
+
+@Component({
+  selector: 'target',
+  template: `{{ service.stream$ | async }}`,
+})
+class TargetComponent {
+  public constructor(public readonly service: TargetService) {}
+}
+
+describe('issue-270', () => {
+  const mock = {
+    stream$: new Subject<number>(),
+  };
+
+  afterAll(() => mock.stream$.complete());
+
+  beforeEach(() => {
+    TestBed.configureTestingModule({
+      declarations: [TargetComponent],
+      providers: [MockProvider(TargetService, mock)],
+    });
+  });
+
+  it('mocks the property', () => {
+    const fixture = MockRender(TargetComponent);
+
+    // default template
+    expect(fixture.nativeElement.innerHTML).toEqual(
+      '<target></target>',
+    );
+
+    // emit 1
+    mock.stream$.next(1);
+    fixture.detectChanges();
+    expect(fixture.nativeElement.innerHTML).toEqual(
+      '<target>1</target>',
+    );
+
+    // emit 2
+    mock.stream$.next(2);
+    fixture.detectChanges();
+    expect(fixture.nativeElement.innerHTML).toEqual(
+      '<target>2</target>',
+    );
+  });
+});