Deprecate PromiseProxyMixin, Enumerable, and Observable (mixins, RFC#… by NullVoxPopuli · Pull Request #21588 · emberjs/ember.js

NullVoxPopuli · 2026-08-31T21:00:44Z

Supersedes:

Deprecate PromiseProxyMixin, Enumerable and Observable per RFC 1116 #21583

Advancement:

Advance RFC #1116 "Deprecating Mixin Support" to Stage Ready for Release rfcs#1143

RFC:

Deprecate Mixin Support rfcs#1116

Guides:

Best viewed with:

Note

Because of the strategy of this deprecation (internal + public extends + deprecate), our tests don't have a lot of the testUnless stuff. We still need the tests because many of these mixins are still used internally. This makes this deprecation a bit different from the other ones due to how entangled mixins our in the codebase

NullVoxPopuli · 2026-08-31T21:02:13Z

this is weird, sure, but also trying to deprecate all this stuff, while heavily used internally, and not throwing deprecations on it is difficult -- I'm super looking forward to the cleanup for v8

github-actions · 2026-08-31T21:03:06Z

📊 Size report

Tarball size — 1.2 MB → 1.2 MB

dist/dev `0.6%↑`

File	Before (Size / Brotli)	After (Size / Brotli)
Total _{(Includes all files)}	`2.1 MB` / `493.9 kB`	^0.6%↑`2.1 MB` / ^0.8%↑`497.9 kB`

Show files (31 files)

File	Before (Size / Brotli)	After (Size / Brotli)
`./packages/@ember/-internals/deprecations/index.js`	`6.5 kB` / `1.7 kB`	^44%↑`9.3 kB` / ^11%↑`1.9 kB`
`./packages/@ember/-internals/runtime/lib/mixins/-proxy-internal.js`	—	`4 kB` / `1.3 kB`
`./packages/@ember/-internals/runtime/lib/mixins/-proxy.js`	`4 kB` / `1.3 kB`	^-77.1%↓`921 B` / ^-70%↓`403 B`
`./packages/@ember/-internals/runtime/lib/mixins/action_handler-internal.js`	—	`1.6 kB` / `639 B`
`./packages/@ember/-internals/runtime/lib/mixins/action_handler.js`	`6.2 kB` / `1.7 kB`	^-11.5%↓`5.5 kB` / ^-14.1%↓`1.5 kB`
`./packages/@ember/-internals/runtime/lib/mixins/container_proxy-internal.js`	—	`990 B` / `358 B`
`./packages/@ember/-internals/runtime/lib/mixins/container_proxy.js`	`1.2 kB` / `422 B`	^-10%↓`1.1 kB` / ^-7.82%↓`389 B`
`./packages/@ember/-internals/runtime/lib/mixins/registry_proxy-internal.js`	—	`1.6 kB` / `541 B`
`./packages/@ember/-internals/runtime/lib/mixins/registry_proxy.js`	`1.6 kB` / `566 B`	^-48.1%↓`806 B` / ^-45.1%↓`311 B`
`./packages/@ember/-internals/runtime/lib/mixins/target_action_support-internal.js`	—	`2.8 kB` / `836 B`
`./packages/@ember/-internals/runtime/lib/mixins/target_action_support.js`	`4.9 kB` / `1.4 kB`	^-77.9%↓`1.1 kB` / ^-68.4%↓`427 B`
`./packages/@ember/-internals/views/lib/mixins/action_support-internal.js`	—	`1.7 kB` / `637 B`
`./packages/@ember/-internals/views/lib/mixins/action_support.js`	`1.5 kB` / `615 B`	^-56%↓`680 B` / ^-50.4%↓`305 B`
`./packages/@ember/array/index-internal.js`	—	`15 kB` / `3.6 kB`
`./packages/@ember/array/index.js`	`17.5 kB` / `4.4 kB`	^-76.3%↓`4.1 kB` / ^-71.6%↓`1.2 kB`
`./packages/@ember/controller/controller-internal.js`	—	`2.9 kB` / `1 kB`
`./packages/@ember/controller/index.js`	`4.9 kB` / `1.6 kB`	^-43.2%↓`2.8 kB` / ^-42.4%↓`924 B`
`./packages/@ember/enumerable/-internal.js`	—	`416 B` / `207 B`
`./packages/@ember/enumerable/index.js`	`570 B` / `281 B`	^65%↑`939 B` / ^43%↑`403 B`
`./packages/@ember/enumerable/mutable-internal.js`	—	`504 B` / `230 B`
`./packages/@ember/enumerable/mutable.js`	`623 B` / `288 B`	^57%↑`981 B` / ^39%↑`399 B`
`./packages/@ember/object/mixin-internal.js`	—	`17 kB` / `4.5 kB`
`./packages/@ember/object/mixin.js`	`610 B` / `230 B`	^340%↑`2.7 kB` / ^252%↑`810 B`
`./packages/@ember/object/observable-internal.js`	—	`4.4 kB` / `1.1 kB`
`./packages/@ember/object/observable.js`	`6.7 kB` / `1.8 kB`	^-54.2%↓`3.1 kB` / ^-43%↓`1 kB`
`./packages/shared-chunks/computed-CXIM4Sjc.js`	`33.9 kB` / `7.9 kB`	—
`./packages/shared-chunks/evented-{hash}.js`	`3.3 kB` / `856 B`	^6%↑`3.5 kB` / `856 B`
`./packages/shared-chunks/index-{hash}.js`	`51.9 kB` / `13 kB`	^20%↑`62.6 kB` / ^-3.32%↓`12.5 kB`
`./packages/shared-chunks/mixin-M88Ghbyw.js`	`18.5 kB` / `4.8 kB`	—
`./packages/shared-chunks/properties-B5iTkmNj.js`	—	`33.9 kB` / `7.9 kB`
`./packages/shared-chunks/template-{hash}.js`	`491 B` / `203 B`	^118%↑`1.1 kB` / ^98%↑`401 B`

dist/prod `0.7%↑`

File	Before (Size / Brotli)	After (Size / Brotli)
Total _{(Includes all files)}	`1.9 MB` / `451.2 kB`	^0.7%↑`1.9 MB` / ^0.9%↑`455.3 kB`

Show files (29 files)

File	Before (Size / Brotli)	After (Size / Brotli)
`./packages/@ember/-internals/deprecations/index.js`	`6.2 kB` / `1.6 kB`	^46%↑`9 kB` / ^11%↑`1.8 kB`
`./packages/@ember/-internals/runtime/lib/mixins/-proxy-internal.js`	—	`3.1 kB` / `1 kB`
`./packages/@ember/-internals/runtime/lib/mixins/-proxy.js`	`3.1 kB` / `1 kB`	^-69.9%↓`921 B` / ^-60.9%↓`403 B`
`./packages/@ember/-internals/runtime/lib/mixins/action_handler-internal.js`	—	`1.1 kB` / `467 B`
`./packages/@ember/-internals/runtime/lib/mixins/action_handler.js`	`5.7 kB` / `1.6 kB`	^-4.43%↓`5.5 kB` / ^-7.24%↓`1.5 kB`
`./packages/@ember/-internals/runtime/lib/mixins/container_proxy-internal.js`	—	`990 B` / `358 B`
`./packages/@ember/-internals/runtime/lib/mixins/container_proxy.js`	`1.2 kB` / `421 B`	^-10%↓`1.1 kB` / ^-7.6%↓`389 B`
`./packages/@ember/-internals/runtime/lib/mixins/registry_proxy-internal.js`	—	`1.4 kB` / `508 B`
`./packages/@ember/-internals/runtime/lib/mixins/registry_proxy.js`	`1.3 kB` / `474 B`	^-38.4%↓`806 B` / ^-34.4%↓`311 B`
`./packages/@ember/-internals/runtime/lib/mixins/target_action_support-internal.js`	—	`2.5 kB` / `760 B`
`./packages/@ember/-internals/runtime/lib/mixins/target_action_support.js`	`4.6 kB` / `1.3 kB`	^-77.4%↓`1 kB` / ^-68%↓`411 B`
`./packages/@ember/-internals/views/lib/mixins/action_support-internal.js`	—	`1.1 kB` / `472 B`
`./packages/@ember/-internals/views/lib/mixins/action_support.js`	`923 B` / `404 B`	^-26.3%↓`680 B` / ^-24.5%↓`305 B`
`./packages/@ember/array/index-internal.js`	—	`13.3 kB` / `3.3 kB`
`./packages/@ember/array/index.js`	`15.7 kB` / `4.1 kB`	^-73.7%↓`4.1 kB` / ^-69.7%↓`1.2 kB`
`./packages/@ember/controller/controller-internal.js`	—	`2.9 kB` / `1.1 kB`
`./packages/@ember/controller/index.js`	`4.9 kB` / `1.6 kB`	^-43.2%↓`2.8 kB` / ^-42.1%↓`929 B`
`./packages/@ember/enumerable/-internal.js`	—	`416 B` / `207 B`
`./packages/@ember/enumerable/index.js`	`570 B` / `281 B`	^65%↑`939 B` / ^43%↑`403 B`
`./packages/@ember/enumerable/mutable-internal.js`	—	`504 B` / `230 B`
`./packages/@ember/enumerable/mutable.js`	`623 B` / `288 B`	^57%↑`981 B` / ^39%↑`399 B`
`./packages/@ember/object/mixin-internal.js`	—	`15.3 kB` / `4 kB`
`./packages/@ember/object/mixin.js`	`497 B` / `207 B`	^440%↑`2.7 kB` / ^291%↑`810 B`
`./packages/@ember/object/observable-internal.js`	—	`3.9 kB` / `1 kB`
`./packages/@ember/object/observable.js`	`6.2 kB` / `1.7 kB`	^-50.4%↓`3.1 kB` / ^-39.4%↓`1 kB`
`./packages/shared-chunks/computed-ZvOk7SJQ.js`	`27.9 kB` / `6.5 kB`	—
`./packages/shared-chunks/evented-{hash}.js`	`3.3 kB` / `855 B`	^6%↑`3.5 kB` / ^-0.12%↓`854 B`
`./packages/shared-chunks/mixin-AGmJaAAY.js`	`16.7 kB` / `4.4 kB`	—
`./packages/shared-chunks/properties-D102MiiO.js`	—	`27.9 kB` / `6.5 kB`

smoke-tests/v2-app-template/dist `1%↑`

File	Before (Size / Brotli)	After (Size / Brotli)
`./assets/api-{hash}.js`	`291.4 kB` / `78.2 kB`	^0.8%↑`293.7 kB` / ^0.2%↑`78.4 kB`
`./assets/modules-{hash}.js`	`30.1 kB` / `9.3 kB`	^8%↑`32.4 kB` / ^4%↑`9.7 kB`
Total _{(Includes all files)}	`344.2 kB` / `95.3 kB`	^1%↑`348.8 kB` / ^0.6%↑`95.9 kB`

smoke-tests/v2-app-hello-world-template/dist `-1.86%↓`

File	Before (Size / Brotli)	After (Size / Brotli)
`./assets/main-{hash}.js`	`134.9 kB` / `37.6 kB`	^-1.87%↓`132.4 kB` / ^-1.43%↓`37 kB`
Total _{(Includes all files)}	`135.2 kB` / `37.7 kB`	^-1.86%↓`132.7 kB` / ^-1.42%↓`37.2 kB`

_{🤖 This report was automatically generated by wyvox/pkg-size}

NullVoxPopuli · 2026-08-31T21:15:42Z

+class EmberObject extends CoreObject {
+  static {
+    // `extend(Observable)` would fire the Observable deprecation for every app.
+    this.PrototypeMixin.reopen(Observable);


see note about weirdness here: https://github.com/emberjs/ember.js/pull/21588/changes#diff-a717c1b4c9ec49161fcdbe9544aba7640f2bfebc3c924e980d4645927c29da0c

RFC #1116 deprecates applying Ember's mixins, but Ember's own internals are built on several of them. Those mixins need to exist twice: an internal copy that applies silently, and a public copy that emits the deprecation. This is the mechanical half -- the six mixins under @ember/-internals move to `-internal` filenames with their contents unchanged, and their importers follow. The public, deprecating copies are added in the next commit. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01KPGHrcnbnsLd433MgECeM5

Every mixin Ember applies to its own classes now exists twice: the internal copy applies silently, and the public copy wraps it and emits the deprecation from `init`. The public copies keep the API documentation; the internal copies carry the implementation. `Mixin` itself gets the same treatment -- `InternalMixin` holds the machinery and `Mixin.create` is the deprecating subclass -- which lets the `INTERNAL_MIXIN_CREATE` symbol go away entirely. Because the two copies are distinct objects, `meta.hasMixin` would no longer match a public mixin against an object that only ever had the internal copy applied. `DeprecatedMixin` overrides `detect` to look through to the wrapped copy, so `EmberArray.detect(someArrayProxy)` keeps working while the deprecation is live. Ember's own tests that exercise a mixin's behavior now apply the internal copy, matching what the framework does; tests that specifically cover the deprecation keep using the public copy. `EmberObject` already applies the internal `Observable`, so `observable_test` no longer re-applies the public one on top. The internal copies are kept out of `renamed-modules` so they are not advertised as importable module paths. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01KPGHrcnbnsLd433MgECeM5

NullVoxPopuli · 2026-09-02T17:26:30Z

i'm 🤷 on if these should us the public copies or not

we will be deleting the public code ahead of when we cleanup our own code, so perhaps the way this is is better

for how big this change, I 100% think we should rely on the existing tests as much as we can

NullVoxPopuli · 2026-09-02T17:27:40Z

  send(actionName: string, ...args: unknown[]): void;
 }
-const ActionSupport = Mixin[INTERNAL_MIXIN_CREATE]({
-  send(actionName: string, ...args: unknown[]) {


this deprecation does still exist in the internal copy

NullVoxPopuli · 2026-09-03T14:03:49Z

I didn't want to expose all these new internal files as importable things, so they got filtered out

NullVoxPopuli · 2026-09-03T14:50:16Z

I need to add quite a few more deprecation guides, because all of these are technically importable

NullVoxPopuli mentioned this pull request Aug 31, 2026

Deprecate PromiseProxyMixin, Enumerable and Observable per RFC 1116 #21583

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NullVoxPopuli commented Aug 31, 2026

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NullVoxPopuli force-pushed the nvp/deprecate-mixin-followups branch from 42d121c to 2271ebc Compare August 31, 2026 21:04

This was referenced Aug 31, 2026

RFC#1116: Deprecate mixinables ember-learn/deprecation-app#1435

Merged

Advance RFC #1116 "Deprecating Mixin Support" to Stage Ready for Release emberjs/rfcs#1143

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NullVoxPopuli marked this pull request as ready for review August 31, 2026 21:14

NullVoxPopuli commented Aug 31, 2026

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NullVoxPopuli requested a review from kategengler August 31, 2026 21:20

NullVoxPopuli-ai-agent mentioned this pull request Aug 31, 2026

Sketch: INTERNAL_MIXIN_EXTEND instead of static block for EmberObject #21589

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NullVoxPopuli force-pushed the nvp/deprecate-mixin-followups branch from 2271ebc to 89683e8 Compare September 1, 2026 22:16

NullVoxPopuli force-pushed the nvp/deprecate-mixin-followups branch from 384cda3 to d6f0090 Compare September 2, 2026 16:49

NullVoxPopuli force-pushed the nvp/deprecate-mixin-followups branch from d6f0090 to 075a2b2 Compare September 2, 2026 17:09

NullVoxPopuli commented Sep 2, 2026

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NullVoxPopuli marked this pull request as draft September 2, 2026 17:38

NullVoxPopuli commented Sep 3, 2026

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NullVoxPopuli marked this pull request as ready for review September 3, 2026 14:03

NullVoxPopuli commented Sep 3, 2026

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NullVoxPopuli mentioned this pull request Sep 11, 2026

The rest of the deprecation guides for mixins / RFC 1116 ember-learn/deprecation-app#1437

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NullVoxPopuli added a commit to ember-learn/deprecation-app that referenced this pull request Sep 11, 2026

Write the guides for emberjs/ember.js#21588

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📊 Size report

dist/dev 0.6%↑

dist/prod 0.7%↑

smoke-tests/v2-app-template/dist 1%↑

smoke-tests/v2-app-hello-world-template/dist -1.86%↓

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dist/dev `0.6%↑`

dist/prod `0.7%↑`

smoke-tests/v2-app-template/dist `1%↑`

smoke-tests/v2-app-hello-world-template/dist `-1.86%↓`