fix 430, support ember-source 3.13

[ghost]

This PR fixes #430 and adds support for ember-source@3.13.x.
See #450 for the background conversation and root cause analysis (thanks to @simonihmig 😄 ).

I do a couple things here.

1. add a failing case for Setting same properties name causing tests fail #430, (Try to recreate problem with properties in unit tests #431)
2. refactored the state removal logic to be more explict and only clean up keys that a user has set. While debugging I found it somewhat confusing we were cleaning up all properties on the test context. e.g. set, get, and others. I changed it to only tear down user defined keys and owner.
3. We need to change the main property clean up to this.set('someKey', null). This properly delegates the setter behavior for the tracked property logic of ember-source >= 3.13

Change 2 is optional so I can rebase with only 1 and 3 if is preferred.

[kevinansfield]

👍 tested and confirmed working for me 🎉 Looks like the only tests still failing in our test suite now are more directly related to 3.13

[Turbo87]

that's good news. thanks for testing @kevinansfield!

[ghost]

I found this actually breaks when you use this.name = 'something' in subsequent tests. @kobsy's work in #461 accounts for that but takes a slightly different approach to establish an entirely new testing context.

[kevinansfield]

Hmm, I think I was too quick to assume our remaining failing tests were 3.13 related. It appears the problem is properties set on this persisting to the next test. Code that's failing...

it('triggers multiple uploads', async function () {
    await render(hbs`{{#gh-uploader files=files}}{{/gh-uploader}}`);
    this.set('files', [createFile(), createFile(), createFile()]);
    await settled();

    expect(server.handledRequests.length).to.equal(3);

});

it('triggers onStart when upload starts', async function () {
    this.set('uploadStarted', sinon.spy());
    await render(hbs`{{#gh-uploader files=files onStart=(action uploadStarted)}}{{/gh-uploader}}`);
    this.set('files', [createFile(), createFile()]);
    await settled();

    expect(this.get('uploadStarted').calledOnce).to.be.true;
});

The second test is failing because didReceiveAttrs is firing twice on the component as expected but the first time it's called the files value on the component is the same as the first test.

Re-checked 3.12 to make sure and files is undefined the first time didReceiveAttrs is called.

[kevinansfield]

Tested against #462 and that one is fully working 👍

[ghost]

Closing this PR as well because it doesn't fully resolve the issue. #462 does so because it uses the corresponding teardown method from Ember's tracked properties. There are questions to address there and feedback on a possible public API to do this.