Update QUnit test adapter to be 2.0 compatible

[trentmwillis]

An attempt to fix #13696.

The good: it works! There are some other things to be cleaned up in the ecosystem (such as the use of setup/teardown), but this makes all the code in Ember itself QUnit 2.0 compatible.

The bad: it relies on some private QUnit knowledge. Without some revamping of how tests are run though I don't see much way around that.

[rwjblue]

Can you confirm what versions of QUnit are supported by this change?

[rwjblue]

The bad: it relies on some private QUnit knowledge.

How likely is this to break in the future? Seems somewhat like QUnit private API...

Without some revamping of how tests are run though I don't see much way around that.

I'd love to set some time aside and ensure that the proposed testing revamp properly accounts for this. Lets circle around...

[trentmwillis]

Can you confirm what versions of QUnit are supported by this change?

Will look into this tomorrow or Monday probably.

How likely is this to break in the future?

I don't know of anything upcoming that would break it and the existing code has been around awhile, so I would say unlikely.

I'd love to set some time aside and ensure that the proposed testing revamp properly accounts for this.

Definitely. As a bit of perspective, I think the crux of the matter is that QUnit assumes you know when your test is async and that you shouldn't be done with async until everything has been finished. Whereas Ember seems to treat a test as having async "phases" (that start and stop) rather than the whole thing being async.

[trentmwillis]

After discussing in person, going to close this in favor of defining a solution in ember-qunit.