Task overriding broken in 0.7.11

In 0.7.10, overriding a task definition in an extend call worked as I’d expect a normal property override to, but with the getter changes in 0.7.11 it now throws TypeError: Cannot set property go of [object Object] which has only a getter.

const MyThing = Ember.Object.extend({
  go: task(function*() { return 'yes'; })
});

const MyOtherThing = MyThing.extend({
  go: task(function*() { return 'actually, no'; })
});

[camhux]

Just adding a no-op set trap seems to fix this:

let cp = this;
Object.defineProperty(proto, taskName, {
  get() {
    return cp.get(this, taskName);
  },
  set() {/*trap*/},
});

This looks like it shouldn’t work (this line, in fact, has no effect with this setter) but it nonetheless causes a test case to pass. As far as I can tell, thanks to Ember delegating to the descriptor’s setup method here, the descriptor ends up properly set/reset when overridden.

I have this change and test case on a fork. I don’t mind opening a PR for review with the caveat that I don’t fully grok the Ember property mechanisms involved, which is not a feeling I like when submitting code.

[machty]

I believe @camhux is correct. ember-metal does a property set when merging mixins, so we have write an empty setter so that things don’t below up. I’ve implemented this in #83