upgrade ember-test-selectors to get around the getWithDefault deprecation

[NullVoxPopuli]

See: #846

[mixonic]

@NullVoxPopuli can you rebase? I'd like to sanity check this against Addepar's internal usage but it seems reasonable.

[NullVoxPopuli]

Rebased!

[mixonic]

This was rebased onto 3.0.0-3 or something. I rebased it onto the 3.0-beta branch which is what it targets and pushed.

[mixonic]

@NullVoxPopuli per the changelog in https://github.com/simplabs/ember-test-selectors/blob/master/CHANGELOG.md, v2 of ember-test-selectors is the last version to support Ember versions before 2.16. As this library must support Ember 2.8 (or Addepar won't really be able to us it), we can't bump the version of the test selector dependency past 2.x at this time.

[NullVoxPopuli]

Maybe we release another v2 version that addresses the deprecation?

[mixonic]

@NullVoxPopuli Yeah honestly getWithDefault is very easy to avoid. It would be fairly straightforward to write the patch upgrading ember-test-selector 2.x if the maintainers are willing to accept it.

I will say that ember-table is not going to be able to drop support for 2.x (even 2.8) for a good while. I would plan for 6 months of Ember 2.8 support and a year of Ember 2.x support as a rough, very rough, estimation. I hope that context helps you figure out next steps for your own contributions/efforts.

[NullVoxPopuli]

It does, thanks! 🎉