Cause waitFor to reject if awaited action is never called.

[haroldtreen]

Description

Changes the waitFor promise to reject if the provided action is never called.

Example

it('must call SOME_ACTION_THAT_WILL_NEVER_FIRE', () => { 
    const saga = function*() { yield; }
    sagaTester.start(saga);
   return sagaTester.waitFor('SOME_ACTION_THAT_WILL_NEVER_FIRE');
});

Before

Error: Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.

• ❌ Not clear what went wrong.
• ❌ Test hangs for 2 seconds before failing.

After

Error: SOME_ACTION_THAT_WILL_NEVER_FIRE was waited for but never called.

• ✅ Communicates that the expected behavior didn't occur.
• ✅ Fails as soon as the saga is exhausted.

[3LOK]

@haroldtreen hi - Looks good, however I think I'd like a few days to write some tests since I think I have some ideas about use cases when this solution might not work (and I might be wrong of course, just need to be sure). Is that ok?

[haroldtreen]

Makes sense! I was also wondering how this might work with

• multiple sagas
• a tester that's been reset
• extra middleware

If you know the cases, I'm also happy to write more tests :).

[3LOK]

@haroldtreen well, could find a use case to make it fail. merging and keeping my ears open to issues.

[haroldtreen]

Yay! Thanks @3LOK.

What was the failure case?

[3LOK]

@haroldtreen tested all the cases you wrote there. also tried to make redux-saga call the "done" in various cases that won't really be considered "done". Couldn't, so all seems to be good :)

[tuzmusic]

This doesn't seem to be working for me. The code below is just trying to see this PR's feature working, as per the example at the top of this page.

describe("integration", () => {
  let sagaStore;
  beforeEach(() => {
    sagaStore = new SagaTester({});
    sagaStore.start(authSaga);
  });

  it("returns an error for an invalid username", () => {
    sagaStore.dispatch(login(creds.badUser));
    return sagaStore.waitFor("FAKE_TYPE");
  });
});

And I'm getting the same Timeout - Async callback was not invoked within the 5000ms timeout specified by jest.setTimeout.Error: that this was designed to fix. Am I doing something wrong, or is this an issue?