Testing with Jasmine - Async object not exists

[nischi]

RxJS version:
5.3.0

Code to reproduce:
https://github.com/nischi/angular-testing
angular/angular#15889

Expected behavior:
Test should fail because array do not exists

Actual behavior:
Test pass

Additional information:
angular/angular#15889
I have discussed that with the angular team, but they said its a problem with rxjs and jasmine not angular itself, thats the reason why i put the issue here as well.

[kwonoj]

It doesn't seem like Rx issue, jasmine seems try to be smart to catch some of unexpected exceptions thrown, and it's shallowed somehow. So in your test code, it asserts

expect(obj.data.length).toBe(100);

and obj.data is undefined, so evaluating obj.data.length will throws exception - reason there isn't any execution to assertion actually occurred.

instead, if you make data property actually available,

class myObject {
  count = 0;
  data: mySecondObject[] = []; //empty array instance exposes `length`
}

now you can see test fails. If you change your assertion like below,

try {
  const a = obj.data.length;
  expect(a).toBe(100);
} catch (e) {
  console.log(e);
}

you can see exception more clear like

It is hard to say what makes this causes exactly though, my current assumption is it's somewhat unrelated to Rx's regression - if you're throwing unhandled exception in observer callbacks, Observable can't do lot of things pretty much.

[nischi]

Sure i can set the Array to a default value. But if i do a async call to an api it could be taht the "data" is not existing. If that is the case it should be fail. And not pass as it does right now.

Do you think i should open an issue on jasmin project?

[kwonoj]

So it seems like #2565 is exact same symptom. Since it isolates cases more clear without involving ng or jasmine, I'm closing this issue and track this under #2565. I need to dig into history if this is intended changes or not.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.