Patrick Brosset <:pbro> Reporter
	Description • 7 years ago

In bug 1350645 we're trying to get rid of our dependencies on the soon-to-be-removed addon-on SDK APIs.
One such API is sdk/core/heritage which we use in ~50 places:

http://searchfox.org/mozilla-central/search?q=sdk%2Fcore%2Fheritage&path=devtools

We should replace this with ES classes now that they are supported.

	Patrick Brosset <:pbro> Reporter
	Comment 1 • 7 years ago

DevTools bug triage (filter on CLIMBING SHOES).

	Matteo Ferretti [:zer0] [:matteo]
	Comment 2 • 7 years ago

Some additional information:

1. We should probably ignore the projectEditor since is going away (Bug 1361311), that's bring down to 25 the place where `heritage` is used (view-helpers.js mentioned heritage module, but without actually requiring it).

2. In our code base we have actually two ways to use `heritage` module: one imports `Class`; and one imports `extend`.

The usage of `Class` should be probably replaced by ES6 classes, and where is possible `extend` as well. However, if there is any performance issue in some hot code of using ES6 classes, since they're not JITted (bug 1167472), our most common usage of `extend` is basically this:

   Object.create(prototype, Object.getOwnPropertyDescriptor(properties));

(Actually `extend` can takes more than on property descriptor objects, but I think we don't have this scenario in our code base).

So we could just replace:

    const { extend } = require("sdk/core/heritage");

With:

    const extend = (prototype, properties) =>   Object.create(prototype, Object.getOwnPropertyDescriptor(properties));

For the time being.

	Matteo Ferretti [:zer0] [:matteo]
	Comment 3 • 7 years ago

(In reply to Matteo Ferretti [:zer0] [:matteo] from comment #2)

> our most common usage of `extend` is basically this:
> 
>    Object.create(prototype, Object.getOwnPropertyDescriptor(properties));
>
> So we could just replace:
> 
>     const { extend } = require("sdk/core/heritage");
> 
> With:
> 
>     const extend = (prototype, properties) =>   Object.create(prototype,
> Object.getOwnPropertyDescriptor(properties));

I'm noticing just now the typo; the actual code is with "getOwnPropertyDescriptors" (with "s"); adding for future reference.

	Soledad Penades [:sole] [:spenades]
	Comment 4 • 7 years ago

Given that no dependencies are left, and that the only appearances of sdk/core/heritage on the codebase are in comments, I declare this bug CLOSED! (hopefully)