Ember.js: sinon.useFakeTimers in acceptance tests break if run.later is used

[Gaurav0]

You can use sinon.useFakeTimers in an acceptance test, or you can use run.later in your application, but doing both causes the acceptance test to time out.

Reproduction: https://ember-twiddle.com/d5f34d97be1e75b8258e654f6a482d70?openFiles=tests.acceptance.my-acceptance-test.js%2C

[Gaurav0]

I think the issue is in Backburner.

[morhook]

I think the problem is that sinon.useFakeTimers() is modifying the environment (the timers of the VM JS, as kind-of-everything depends on setTimeout).

You can put a lot of clock.tick(0); to let run the normal async mechanisms of the acceptance utilities (like visit(xx), andThen, etc).

p.s.: I've fixed your twiddle hard-coding a little bit https://ember-twiddle.com/d5f34d97be1e75b8258e654f6a482d70?openFiles=tests.acceptance.my-acceptance-test.js%2C

[morhook]

p.s.2: I've fixed your twiddle, taking out the 'Date' parameter in sinon.useFakeTimers() https://ember-twiddle.com/f2c762d2bdcb25e7329827bf92c91c68?openFiles=tests.acceptance.my-acceptance-test.js%2C

[stefanpenner]

believe this has been addressed: https://github.com/ebryn/backburner.js/pull/179 (although that was merged yesterday) and it still needs to make its way into ember.

[Gaurav0]

@morhook Not putting a Date in sinon.useFakeTimers() kind of defeats the point, the use case is so that Date.now() returns a predictable value, allowing acceptance tests that use the Date to pass regardless of what date it is.

[pixelhandler]

@stefanpenner so does this need a PR for the Backburner update?

[pittst3r]

@pixelhandler I'd be happy to make a follow-up PR in Ember if necessary.

[morhook]

@Gaurav0 sounds fair! Thanks for explaining it to me.

[rwjblue]

Discussed with @turbo87 and we believe this is resolved.

[Turbo87]

yes, https://github.com/BackburnerJS/backburner.js/pull/179/files resolved it and has found its way into one of the recent Ember releases, though I can't say which one specifically fixed it.

[vcipriani]

Just fyi for anyone running into this problem, it looks like the Backburner fix is not included in Ember 2.14. It looks like it is shipping in 2.15.