MockService Not Working in Angular 8

[DineshKumarGovindarajan87]

Description

MockService test case failed.

Issue

Environment

• node -v output: 10.16.0
• npm -v (or yarn --version) output: 6+
• npm ls testdouble (or yarn list testdouble) version: 3.3.0

Failing Test

TypeError: this.appTitle.setTitle is not a function
at new AppComponent (http://localhost:9876/_karma_webpack_/webpack:/src/app/app.component.ts:14:19)
at createClass (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/fesm2015/core.js:24580:1)
at createDirectiveInstance (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/fesm2015/core.js:24400:1)
at createViewNodes (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/fesm2015/core.js:35006:1)
at createRootView (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/fesm2015/core.js:34878:1)
at callWithDebugContext (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/fesm2015/core.js:36407:1)
at Object.debugCreateRootView [as createRootView] (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/fesm2015/core.js:35644:1)
at ComponentFactory_.create (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/fesm2015/core.js:23542:1)
at initComponent (http://localhost:9876/_karma_webpack_/webpack:/node_modules/@angular/core/fesm2015/testing.js:3409:1)
at ZoneDelegate.invoke (http://localhost:9876/_karma_webpack_/webpack:/node_modules/zone.js/dist/zone-evergreen.js:359:1)

Example Repo

var td = require('testdouble')

// Your steps here.
``` 1. beforeEach(async(() => {
   mockAppTitle = td.object(Title.prototype);

    TestBed.configureTestingModule({
      imports: [
        RouterTestingModule
      ],
      declarations: [
        AppComponent
      ],
      providers: [
       { provide: Title , useValue: mockAppTitle}
      ]
    }).compileComponents();
  }));
  beforeEach(() => {
    fixture = TestBed.createComponent(AppComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
    compiled = fixture.debugElement.nativeElement;
  });
  it('should set tilte in header', () => {
    expect(mockAppTitle.setTitle('Demo'));
  });
});

2. In Constructor I assigned the titleService  and used setTitle('Demo') method. 

How to use mockservice in angular 8. any new syntax updated in testdouble 
![Capture](https://user-images.githubusercontent.com/46916258/60346741-6d2b0680-99d9-11e9-9c17-9e11dffbaa0c.PNG)
![Screen1](https://user-images.githubusercontent.com/46916258/60346743-6d2b0680-99d9-11e9-90af-26c57ce4e903.PNG)
![Screen2](https://user-images.githubusercontent.com/46916258/60346744-6dc39d00-99d9-11e9-993a-afe993283419.PNG)


?
Please revert me any suggestion.

[DineshKumarGovindarajan87]

[tgroshon]

Thanks for taking the time to create an issue and including sample code. We have not had a chance to look into the details of your particular case but should by early next week (perhaps later with the upcoming US Holiday).

Standby!
:)

[rosston]

@DineshKumarGovindarajan87 From the information you have provided, it sounds like you are running into an issue with using Angular's dependency injection system. You might want to investigate more on the Angular side of things to determine how to provide a mocked Title.

Additionally, you might want to look at the documentation for td.verify once you've figured out how to provide the mocked value.

I think we should close this issue for now since I think it is outside of the scope of the testdouble.js project.