Test a map inside a pipe in Angular (Isolated Test)-CodePudding

I have a method that has a pipe with a map inside of it. When I run the test I can't find a way to get into that map.

This is my component code

public getParents(): void {
    Eif (this.filter.siteId !== null) {
      this.parents$ = this.parentsM().pipe(
        map(items => items.data),
        catchError(error => {
        this.messageService.errorHandler(error);
        return Array<any>();
      }));
    }
  }

This is my Spec.ts code

it("getParents with siteId", async(() => {
      const mockItems:Response = {
      codError: "",
      msgError: "",
      data: "test"}
      let spy = spyOn<any>(component, "parentsM").and.returnValue(scheduled([mockItems], asyncScheduler));
    component.getParents();
    component.parentsM().subscribe(items => {
      expect(items).toEqual(mockItems);
    });
    spy.calls.reset();
  }));

This is my code coverage

CodePudding user response：

Multiple issues here. You actually have to subscribe to this.parents$ to execute the map, which makes your test async. In your test, you're subscribing on the result of parentsM(), which I guess doesn't return exactly this.parents$, so you're not subscribing to the pipe you wrote. You may also use waitForAsync instead of async.

Please try this:

it("getParents with siteId", waitForAsync(() => { // <== waitForAsync
      const mockItems:Response = {
      codError: "",
      msgError: "",
      data: "test"}
      let spy = spyOn<any>(component, "parentsM").and.returnValue(scheduled([mockItems], asyncScheduler));
    component.getParents();
    component.parents$.subscribe(items => { // <== parents$
      expect(items).toEqual(mockItems);
    });
    
    spy.calls.reset();
}));