Angular Mocking Service with multiple signature

Question

In my Angular project, all the Rest services are defined like below, they have 4 signatures

public commandsGet(oem: string, countryCode?: string, observe?: 'body', reportProgress?: boolean): Observable<CommandGetResponse>;
    public commandsGet(oem: string, countryCode?: string, observe?: 'response', reportProgress?: boolean): Observable<HttpResponse<CommandGetResponse>>;
    public commandsGet(oem: string, countryCode?: string, observe?: 'events', reportProgress?: boolean): Observable<HttpEvent<CommandGetResponse>>;
    public commandsGet(oem: string, countryCode?: string, observe: any = 'body', reportProgress = false): Observable<any> {

        return this.httpClient.get<CommandGetResponse>(`${this.basePath}/${oem}/commands/`, params);
    }

I'm writing some tests and trying to mock the service, but I'm getting error "Argument of type 'Observable' is not assignable to parameter of type 'Observable<HttpEvent>'"

it('should return expected commands', (done: DoneFn) => {
            const mockResponse: CommandGetResponse  = {
                data: [
                    { commandname: 'A' },
                    { commandname: 'B' }],
                count: 2
            };
           
            spyOn(commandService, 'commandsGet').and.returnValue(of(mockResponse) as Observable<CommandGetResponse>);
            component.ngOnInit();
            fixture.detectChanges();

            expect(component.commands).toEqual(mockResponse.data);
        });

I have also tried

spyOn(commandService, 'commandsGet').and.returnValue(of(mockResponse));

``

Then I'm getting "Argument of type 'Observable<CommandGetResponse>' is not assignable to parameter of type 'Observable<HttpEvent<CommandGetResponse>>'.

When I define:

const httpResponse = new HttpResponse({ body: mockResponse });
spyOn(commandService, 'commandsGet').and.returnValue(of(httpResponse));

I'm not getting any error but my tests fail as the object returned is not of type "CommandGetResponse"

Any help on this would be welcome.

Thanks

Answer 1

For testing files it does not really matter what types are set, so it's safe to use any and just focus on testing and coverage.

    it('should return expected commands', (done: DoneFn) => {
        const mockResponse: any = { // <- changed here!
            data: [
                { commandname: 'A' },
                { commandname: 'B' }],
            count: 2
        };
       
        spyOn<any>(commandService, 'commandsGet').and.returnValue(of(mockResponse) as any);// <- changed here!
        component.ngOnInit();
        fixture.detectChanges();

        expect(component.commands).toEqual(mockResponse.data);
    });