replace all uses of Ember.copy, Ember.merge w/ Object.assign

[bgentry]

Attempted fix of #834. Not sure if I have to do something weird for the import in ember_debug/libs/promise-assembler.js or not…

[bgentry]

FYI, these same test failures appear to also happen on master. I'll open a separate issue for that.

[RobbieTheWagner]

@teddyzeenny should this import work here?

[teddyzeenny]

I don't think it would, no. Not unless the app being debugged has ember-copy installed as an addon.

[RobbieTheWagner]

So what is your recommendation here?

[teddyzeenny]

There's no way to use Ember addons in ember-debug at the moment. We may be able to eventually work this out by custom-building and including the addons in the ember-debug final build, but I doubt it's going to be simple.

For the sake of this PR, my recommendation would just be to not use Ember.copy in this file as it's not even doing a deep clone. So either properties = {...properties} if our Babel setup supports it, or a simple manual shallow copy by iterating over the properties. Either way, I don't think this function requires an Ember addon.

[bgentry]

Would Obect.assign do the trick?

[teddyzeenny]

@bgentry yes Object.assign works! 👍

[RobbieTheWagner]

@teddyzeenny with that in mind, does that work everywhere? Could we completely remove ember-copy in favor of that?

[teddyzeenny]

ember-copy can do deep clones which Object.assign and { ...spread } cannot, I think that's the difference? If they're all shallow copies we should be able remove ember-copy.

[bgentry]

I updated this PR. It no longer uses ember-copy, instead just using Object.assign everywhere that copy was previously. I'm not certain whether this is ok (if everything is just a shallow copy) so somebody w/ more knowledge should verify that 😄

[RobbieTheWagner]

@bgentry sorry to keep making you change things, but I think we should keep ember-copy in the app code, but just use Object.assign in the ember_debug code, just to be safe. With those changes, I would be fine with merging, since @teddyzeenny said Object.assign was okay for that one case.

[RobbieTheWagner]

As I was typing that, Teddy approved the PR 😂. Let me sync with him offline.

[RobbieTheWagner]

@teddyzeenny thinks this is good to go, and we don't need deep copies, so works for me 👍