CODEWITHSUNDEEP
angularunit-testingjasminekarma-runnerobservable
playerone
playerone

Reputation: 1127

Angular 2 karma unit test for subscriber error

While running code coverage tests I noticed that I didn't cover error handling on subscriber functions. Function to test:

 getVersion() {
    return this.aboutService.getAPIVersion()
        .subscribe(
            info => {
                console.log('info', info);
            },
            error => {
                console.log('error', error);
            }
        );
}

This is function is in the component and it's calling function from service. I managed to write unit test for function from service with mockBackend abd MockError but I don;t know how to do that with wrapper(caller) function.

So far I mocked service with class but I am only covering response and not the errors:

class AboutServiceStub {
    getAPIVersion = jasmine.createSpy('getAPIVersion').and.callFake(
        this.fakedGetAPIVersion
    );

    fakedGetAPIVersion() {
        console.log('fakedGetAPIVersion');
        return Observable.of(new Object(version))
            .map(version => JSON.parse(JSON.stringify(version)));
    }
}

Upvotes: 1

Views: 1523

Answers (1)

Karan Garg
Karan Garg

Reputation: 1103

I had the same scenario where i needed to test the error case just for one test case(for the sake of code coverage).The approach i followed is 1.Get the injected service into the test as follows

aboutService = fixture.debugElement.injector.get(AboutService);

2.Now override the method using

aboutService.getAPIVersion = () => Observable.throw('error');

SO for this particular test the method has been overridden. The exact code might not work,This is something i remember on top of my head .

Upvotes: 1

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