1.13.4 breaks some component unit tests

[thec0keman]

In moving from 1.13.3 -> 1.13.4, some of our unit tests are breaking.

It is a bit hard to nail down exactly because it happens in random places, but the context for the test itself has subject set to nil:

test('it renders', function(assert) {
  var subject = this.subject();
});

=>

TypeError: this.subject is not a function
    at Object.<anonymous> (http://localhost:7357/assets/app.js:72630:26)
    at Object.wrapper (http://localhost:7357/assets/test-support.js:1821:29)
    at Object.Test.run (http://localhost:7357/assets/test-support.js:3502:28)
    at http://localhost:7357/assets/test-support.js:3631:11
    at process (http://localhost:7357/assets/test-support.js:3190:24)
    at begin (http://localhost:7357/assets/test-support.js:3235:2)
    at http://localhost:7357/assets/test-support.js:3251:4

Dropping in a debugger, and the test context is clearly different:

[stefanpenner]

Can you provide a repo that demonstrates this. That will make it more actionable

[twokul]

@thec0keman which version of qunit are you on? in the newest version you need to specify integration: true in order to use this.subject()

[stefanpenner]

@twokul i suspect that is the issue.

[thec0keman]

Running 0.4.1. We are using the needs array which should be flagging them as integration, which works for most of the tests most of the time, and all of the tests in 1.13.3.

@stefanpenner I'll work on extracting some of the failing tests into a repo. Thx.

[stefanpenner]

@thec0keman i believe your bug isn't with ember (this repo), and rather with the https://github.com/switchfly/ember-test-helpers

[mixonic]

@thec0keman the default test helper behavior changed from unit to integration a patch release of ember-test-helpers. I agree with @stefanpenner you may be hitting that.

Please confirm you bumped test-helpers as well to cause this. You can flag all your old component test modules unit: true to restore the old behavior.

[thec0keman]

Thanks for the suggestions. After digging deeper, the problem was being obscured by something in our app munching RSVP errors for tests. this.subject being null was a symptom of the prior test not tearing down correctly, so the app root element was trying to be reused.

The real problem is a template like the following:

{{#if savedOption}}
  <button {{action "removeOption" on="click"}}></button>
{{else}}
  {{input value=inputValue}}
{{/if}}

where removeOption simply nullifies savedOption. There is some weird interplay between removing the button element and adding the input that raises:

Uncaught Error: Assertion Failed: BUG: Render node exists without concomitant env.

I can post a repo demonstrating this if desired.

[stefanpenner]

This appears to be an issue with the test helpers. They should not end up in a bad state like this. Can you open the issue on that repo?

[thec0keman]

Absolutely. Wouldn't the BUG: Render node exists without concomitant env. be Ember related though?

[rwjblue]

A recent update to test helpers should properly handle errors in setup (and not fail like this).

[rwjblue]

@thec0keman - Yes, I would say that would still be an ember issue (though not really related to this issues title or description), can you make a demo JSBin that reproduces?

[thec0keman]

I cannot reproduce this in JSBin. It only seems to be happening with testing, so I'll move the issue to ember-test-helpers (here).

[egemon]

If somebody will every look at the similar issue, I had had one, because my willDestroyElement() hook had threw exception, so element was not destroyed.