I am trying to test a subject as observable, but it is not working as expected
For simplistic I have removed extra logic inside getService2Test subscribe

Below is my function in service class

getTest():Observable<string>{
   let subject = new Subject<string>();
   service2.getService2Test().subscribe(result=>{
        subject.next(result.success);   // result.success = "testing"
        subject.complete();
   });
   
   return subject.asObservable();
}

Below is my test case

it('Testing getTest()',()=>{
   spyOn(service2,'getService2Test').and.returnValue(of("success"));
   service.getTest().subscribe((result)=>{
        expect(result).toEqual("testing");        // never gets invoked in testing
        console.log("Output result: " result);    // not able to see any message
   });
});

The code inside subscribe never executed. I am also getting a warn message of '... has no expectations.'

CodePudding user response：

Your test case doesn't wait for your subscribe and is instantly finished. To fix this implement the resolve callback like this:

it('Testing getTest()', done => {
   spyOn(service2,'getService2Test').and.returnValue(of("success"));
   service.getTest().subscribe((result)=>{
        // verify results
        done();
   });
});

Jest documentation

CodePudding user response：

Thanks Felix, I have tested and below code works

it('Testing getTest()', done => {
   spyOn(service2,'getService2Test').and.returnValue(of("success").pipe(delay(0)));
   service.getTest().subscribe((result)=>{
        console.log(result);   // Prints my results
        done();
   });
});