Shrink hello-world bundle to 109 KB / 34 KB gzip / 30 KB brotli (-29%) by NullVoxPopuli-ai-agent · Pull Request #21387 · emberjs/ember.js

NullVoxPopuli-ai-agent · 2026-05-08T05:57:20Z

Re-applies the PR #21359 / #21360 structural source-file changes on top of nvp/configure-side-effects. Cuts the smoke-tests/v2-app-hello-world-template bundle to 109.03 KB / 34.43 KB gzip / 30.04 KB brotli — a 29% gzip reduction vs. this branch, 55% vs. upstream main.

	hello-world raw	hello-world gzip	hello-world brotli
upstream `main`	242.69 KB	77.13 KB	66.48 KB
this branch (`nvp/configure-side-effects` baseline)	151.92 KB	48.45 KB	42.17 KB
this PR	109.03 KB	34.43 KB	30.04 KB

(raw / gzip from vite build output; brotli from zlib.brotliCompressSync with default options.)

The bundler hints from #21362 (sideEffects: false, the treeshake.moduleSideEffects callback for @glimmer/debug{,-util,-flags}/@glimmer/env/@ember/debug) and the agadoo regression check are already on this branch. This PR is the structural complement: breaking specific dependency chains that pulled the classic-Ember-object stack (Mixin, Observable, Evented, classic Component, computed, observers, RSVP, routing) into the renderer-only path even when an app uses only @glimmer/component + @tracked.

Note

History note: previous attempts at this work (#21362, #21360, #21359) were closed because the base branches they targeted were rebased/superseded. This PR is the same structural changes re-applied on the now-current upstream nvp/configure-side-effects. The bundler-hints subset already merged (the work in #21366 / #21367 / c0de6063f6); this PR adds the source-file restructuring on top.

Pattern

Three shapes recur:

Side-effect-only registration module that classic-app setup-registry imports — bundles that don't pull in setup-registry (the renderComponent-only path) skip the registration and the heavy module it pulls in.
Registration hook on the consumer side so the consumer module no longer statically imports the producer; the producer registers itself as a top-level side effect when loaded by anything else.
Hot-path utility moved to its own file so deep imports skip the heavy module's other side effects.

Wrapped up with a sideEffects field on ember-source/package.json listing the actual side-effect files, so bundlers can tree-shake the rest of the graph aggressively.

Changes

1. Lazy `-mount` and `-outlet` keyword registration

resolver.ts no longer statically imports mountHelper/outletHelper. Replaced with registerBuiltInKeywordHelper(name, helper) and a side-effect file syntax/register-routing-keywords.ts imported by setup-registry.ts. Drops ~138 KB of @ember/routing + ~7 KB of @ember/engine from the renderer-only path.

2. Split classic `Renderer` subclass into `classic-renderer.ts`

Moved Renderer extends BaseRenderer, ClassicRootState, the concrete DynamicScope class, and the View interface out of renderer.ts. Added a RootState interface so RendererState is generic over either root type.

3. `RSVP.defer` → native `Promise` in `renderSettled`

Together with #1, lets the bundle drop the 62 KB rsvp shared chunk entirely.

4. Curly symbols extracted to `curly-symbols.ts`

isCurlyManager is now a brand check (manager[CURLY_COMPONENT_BRAND] === true) instead of an instance check, so the resolver no longer pulls component-managers/curly.ts (the full CurlyComponentManager lifecycle, ~17 KB) just to identify the manager.

5. Classic `Component` class side-effects moved to `register-curly-component.ts`

setInternalComponentManager(CURLY_COMPONENT_MANAGER, Component) and Component.reopenClass({ positionalParams: [] }) no longer run at the top level of component.ts; they're in a side-effect file imported by setup-registry.ts.

6. `DebugRenderTreeImpl` factory moved behind a registry

EnvironmentImpl (in @glimmer/runtime) imported DebugRenderTree statically. New registerDebugRenderTreeFactory lets a side-effect module supply the constructor; getDebugName (the other static reach into debug-render-tree) moved to its own file.

7. Lighter array predicate in `to-bool.ts`

Switched from isArray from @ember/array (which pulls the mixin / Enumerable / Observable / computed graph) to Array.isArray(x) || isEmberArray(x).

8. `contentFor` extracted to `runtime/lib/mixins/content-for.ts`

each-in.ts no longer drags in the ProxyMixin = Mixin.create(...) graph just for an 8-line contentFor function.

9. `@ember/instrumentation` hot path extracted to `lib/internal-instrument.ts`

_instrumentStart and flaggedInstrument moved to a lib file; subscribe/unsubscribe/instrument machinery (dead code unless something subscribes) drops out of bundles that only use the hot path.

10. `@ember/object`'s `action` decorator extracted to `@ember/object/action`

Moved the action decorator implementation behind its own deep import path so @glimmer/component-only apps don't pay for the @ember/object Mixin / CoreObject / Observable graph just to decorate handlers.

11. Extract classic helper handler from resolver

Lazy-register the classic-helper detection (isClassicHelper + CLASSIC_HELPER_MANAGER) via a side-effect file imported from setup-registry.ts. Removes the static import of ./helper from resolver.ts, which was pulling the classic Helper class chain (FrameworkObject → CoreObject → Mixin) into the renderer's path even when the app does not use any classic helpers.

12. Decouple property_events / runloop / property_set from the observer chain

Replaced the static imports of observer.ts (sync flush) and decorator.ts (COMPUTED_SETTERS) with registration hooks; observer.ts and decorator.ts register themselves via top-level side effects when loaded. Drops observer / events / chain-tags / decorator chunks entirely from Glimmer-only bundles.

13. `sideEffects` field on `ember-source/package.json`

Replaces the sideEffects: false declaration with an explicit list of files that actually have top-level side effects (registration files, environment / setGlobalContext callers, opcode handlers, runloop init, validator, etc.) — necessary now that side-effect-only registration files (register-curly-component.ts, register-routing-keywords.ts, debug-render-tree-register.ts) exist and must be preserved when imported only for their side effects.

What's left in the hello-world bundle

After all of the above, the remaining 109 KB raw / 34 KB gzip is essentially just genuine VM runtime + the bare minimum @ember internals: opcode compiler, VM argument handling, VM render loop, renderer setup/environment, backburner + runloop, element-builder, meta/owner/container.

Almost all of the previously-leaked classic-Ember-object machinery (Mixin, Observable, Evented, Component, computed properties, observers, Helper, RSVP, routing) is now gone from the renderer-only path.

Updated tree-shakability snapshot

The new side-effect-free entry points (@ember/-internals/runtime/lib/mixins/content-for, @ember/instrumentation/lib/internal-instrument, @ember/object/action) appear in the shaken snapshots in both dev and prod, confirming agadoo recognizes them as pure.

Test plan

pnpm build:js clean
pnpm test:node 20/20
pnpm --filter ember-test-node-vitest test:node 2/2 (tree-shakability snapshot)
smoke-tests/v2-app-template (classic v2 app) builds + 1/1 test passes
smoke-tests/app-template (v1 app) builds + 1/1 test passes
smoke-tests/v2-app-hello-world-template builds and shrinks as reported
pnpm vite build --mode development --minify false (full dev test suite app) builds clean
pnpm lint:eslint clean for tracked PR files
Browser tests pass in CI

🤖 Generated with Claude Code

…ords Cuts the hello-world smoke test from 243.30 KB / 77.32 KB gzip to 168.59 KB / 53.67 KB gzip — a 30.6% gzip reduction — while leaving the classic v2-app-template essentially flat (+0.21 KB gzip from one extra side-effect import). Three changes, in order of impact: 1. **Lazy `-mount` and `-outlet` keyword registration.** Until now `resolver.ts` statically imported `mountHelper` and `outletHelper`, which transitively pulled `@ember/engine/instance`, `@ember/routing/-internals` (for `generateControllerFactory`), and the rest of the routing/engine graph into every bundle that uses `renderComponent`. Replace the static import with a `registerBuiltInKeywordHelper(name, helper)` registry on the resolver, and add a side-effect-only `syntax/register-routing-keywords.ts` that classic-app setup imports from `setup-registry.ts`. Bundles that don't pull in `setup-registry` (i.e. the hello-world that only uses `@ember/renderer`) drop ~138 KB of routing + ~7 KB of engine code. 2. **Split classic `Renderer` subclass into `classic-renderer.ts`.** Move `Renderer extends BaseRenderer`, `ClassicRootState`, the concrete `DynamicScope` class, and the `View` interface out of `renderer.ts`. Hoists the imports those carry — `OutletView`, `createRootOutlet`, `RootComponentDefinition`, `makeRouteTemplate`, `renderMain`, `guidFor`, `getViewElement`, `getViewId`, `dict`, `createCapturedArgs`, `EMPTY_POSITIONAL`, `curry` — out of the renderer-only bundle. Adds a `RootState` interface so `RendererState` can manage either kind without statically depending on classic code. `setup-registry.ts` now imports `Renderer` from `./classic-renderer`. The renderer entry re-exports the classic types so existing `from '.../renderer'` import sites keep working. 3. **Replace `RSVP.defer` in `renderSettled` with native Promise.** Standalone this didn't move the bundle (rsvp was reachable via other paths), but together with #1 it lets the hello-world bundle drop the 62 KB rsvp shared chunk entirely — `@ember/engine`, `@ember/routing`, and `@ember/-internals/runtime/lib/ext/rsvp` were the remaining consumers, and #1 pulls those off the renderer-only path. Verified: `lint:eslint`, `type-check:internals`, `type-check:types`, `type-check:handlebars`, `test:node`, `test:blueprints`, classic v2-app-template build, hello-world build, and a vite dev build of the full test suite all pass. Browser tests will run in CI. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Builds on the previous classic-renderer/routing-keywords split. The hello-world smoke test goes from 168.59 KB / 53.67 KB gzip to 160.11 KB / 50.88 KB gzip. Cumulative with prior commit: 243.30 KB / 77.32 KB → 160.11 KB / 50.88 KB (34.2% gzip reduction). Classic v2-app-template stays flat (319.55 KB / 99.38 KB). Each change is the same registration pattern as before — a separate side-effect file imported by classic-app `setup-registry`, leaving the heavy module out of the renderer-only path. 1. **Curly symbols extracted to `curly-symbols.ts`.** `BOUNDS`, `DIRTY_TAG`, `IS_DISPATCHING_ATTRS`, and the new `CURLY_COMPONENT_BRAND` live in their own file. `isCurlyManager` is now a brand check (`manager[CURLY_COMPONENT_BRAND] === true`) instead of an instance check, so the resolver no longer pulls in `./curly` (the full `CurlyComponentManager` lifecycle, ~17 KB) just to identify the manager. `curly.ts` re-exports the symbols for back-compat and tags `CURLY_COMPONENT_MANAGER` with the brand. `classic-renderer.ts` and `resolver.ts` now import from `curly-symbols.ts`. 2. **`@ember/-internals/glimmer/lib/component`'s top-level side effects moved to `register-curly-component.ts`.** `setInternalComponentManager(CURLY_COMPONENT_MANAGER, Component)` and `Component.reopenClass({ positionalParams: [] })` ran at module load time, which kept the full classic `Component` class graph reachable from anything that imported `@ember/component` (e.g. `@glimmer/component`'s `setComponentManager`/`capabilities` imports). The registration now lives in a side-effect-only file imported by `setup-registry.ts`, so classic apps still get it on boot. 3. **`DebugRenderTreeImpl` factory moved behind a registry in `@glimmer/runtime/.../environment.ts`.** Previously `EnvironmentImpl` imported `DebugRenderTree` statically and only constructed one when `delegate.enableDebugTooling` was true — but the import alone pulled the whole class (and its `getDebugName` cousin) into every bundle. New `registerDebugRenderTreeFactory` lets a side-effect module (`debug-render-tree-register.ts`) supply the constructor; without that import, `env.debugRenderTree` stays `undefined` even when the delegate flag is set. Classic apps re-register it via `setup-registry.ts`. `getDebugName` was the other static reach into `debug-render-tree`, so it moved to its own file (`get-debug-name.ts`) that opcodes can import without dragging the rest in. 4. **`to-bool.ts` swapped `isArray` from `@ember/array` for `Array.isArray(x) || isEmberArray(x)`.** `isArray` from `@ember/array` calls `EmberArray.detect`, which transitively pulls `@ember/array`'s entire mixin/Enumerable/Observable/computed graph (~16 KB) just to test array-ness inside `{{#if}}`. Using `isEmberArray` from `@ember/array/-internals` (a WeakSet brand set in `EmberArray#init`) covers all instances of EmberArray-mixed classes — the same set the old check covered in practice. Verified: lint clean, all type-checks pass, `test:node` 20/20, `test:blueprints` 265/265, both smoke-test apps build. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Two more lazy-load splits on top of the previous round. Hello-world goes from 160.11 KB / 50.88 KB → 159.49 KB / 50.67 KB. The classic v2-app-template also gets a small win (319.55 → 318.27 KB raw, 99.38 → 98.94 KB gzip). Cumulative from baseline: 243.30 KB / 77.32 KB → 159.49 KB / 50.67 KB (34.5% gzip reduction). 1. **`contentFor` extracted to `runtime/lib/mixins/content-for.ts`.** `each-in.ts` (which the renderer registers as the `-each-in` keyword helper) imports `contentFor` to unwrap proxies before iterating. Until now that import dragged in `runtime/lib/mixins/-proxy`, which defines `ProxyMixin = Mixin.create(...)` at module scope — the entry point to the entire EmberObject / Mixin / computed graph (proxy.ts imports `Mixin`, `computed`, `defineProperty`, `set`, etc.). Moving the 8-line `contentFor` function into its own file lets the renderer path keep proxy support without paying for the rest of the proxy mixin's transitive imports. `-proxy.ts` re-exports `contentFor` from the new file for back-compat. 2. **`@ember/instrumentation` hot path extracted to `instrumentation/lib/internal-instrument.ts`.** `_instrumentStart` (called by the resolver, curly manager, outlet/root/route-template managers) and `flaggedInstrument` (called by the views state machine) used to live in `index.ts` alongside `subscribe`, `unsubscribe`, `instrument`, etc. — most of which are dead code unless something actually subscribes (e.g. Ember Inspector). Moved `_instrumentStart`, `flaggedInstrument`, `subscribers`, the cache helpers, and `NOOP` to the lib file, with `index.ts` re-exporting them via `export ... from`. The `no-barrel-imports` autofix then rewrites internal callers to deep-import from the lib file. Net result: the `instrumentation/index.js` chunk (subscribe / unsubscribe / instrument machinery) drops out of bundles that only use the hot path. `package.json`'s `ember-addon.renamed-modules` map gains an entry for `runtime/lib/mixins/content-for.js` — that's emitted automatically by the `packageMeta` rollup plugin, no manual edit. Verified: lint clean, all type-checks pass, `test:node` 20/20, `test:blueprints` 265/265, both smoke-test apps build. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Hello-world: 159.49 KB / 50.67 KB → 134.17 KB / 42.90 KB gzip (–25 KB raw / –7.8 KB gzip). Classic v2-app-template gets a small bonus too (319.55 → 317.74 KB raw, 99.38 → 98.77 KB gzip). Cumulative from the original 243.30 KB / 77.32 KB baseline: a **44.5% gzip reduction**. Added a `sideEffects` field to `ember-source/package.json` listing the files that actually have top-level side effects, which by inversion tells bundlers that everything else is side-effect-free. With the classic-renderer / register-curly-component / register-routing-keywords splits already done in this PR, the renderer-only path no longer reaches into any of the side-effect files, so vite/rolldown can drop the rest of the graph it pulled in transitively (mostly the classic `Component` class and its CoreView/Mixin chain that vite was previously evaluating via `@ember/component`'s `default` re-export). The list covers: - **Registration modules created in this PR** (`setup-registry*`, `register-routing-keywords*`, `register-curly-component*`, `debug-render-tree-register*`) — these mutate global state on import. - **`environment*` files** (in `@ember/-internals/glimmer/` and `@glimmer/runtime/`) — call `setGlobalContext(...)` and the `_backburner.on(...)` lifecycle hookups at module top level. - **`@glimmer/runtime/lib/compiled/opcodes/**`** — every opcode file registers handlers via `APPEND_OPCODES.add(...)` at module load. - **`@glimmer/runtime/lib/helpers/**` and `lib/modifiers/**`** — setHelperManager / setModifierManager calls. - **`@ember/-internals/glimmer/lib/components/**`** — Input, Textarea, LinkTo all call `setInternalComponentManager(...)` at top level. - **`runtime/lib/component/template-only*`, `runtime/lib/vm/low-level*`** — template-only manager registration and VM bootstrap. - **`runloop/`, `manager/`, `validator/`, `global-context/`, `destroyable/`, `canary-features/`, `-internals/environment/`, `-internals/runtime/lib/ext/rsvp*`, `-internals/views/lib/system/event_dispatcher*`** — top-level side effects in those modules' index/init files. - **`./dist/dev/**`** — keep dev builds maximally unmolested for inspector / debugging tooling that may rely on dev-only side effects. Anything outside that list — class-definition files like `component.ts`, `core_view.ts`, `core.ts`, mixin files, computed-property files — is treated by bundlers as pure, so unused exports drop out cleanly. Verified: lint clean, all type-checks pass, `test:node` 20/20, `test:blueprints` 265/265, `pnpm test` for both `smoke-tests/v2-app-template` (classic v2 app) and `smoke-tests/app-template` (v1 app) pass 1/1 each, hello-world builds and shrinks as reported. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CI lint caught these without the local eslint cache: the no-barrel-imports rule wants `flaggedInstrument` imported from `@ember/instrumentation/lib/internal-instrument` (the actual source) rather than the barrel. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

The `addMixin` / `hasMixin` / `forEachMixins` methods only existed on `Meta` to be called by `@ember/object/mixin`. Keeping them on the class forced a static reference from `Meta` (reachable from the renderer through the property accessor / tag chain) into the classic `Mixin` graph. Move them out as standalone functions (`metaAddMixin` / `metaHasMixin` / `metaForEachMixins`) in `mixin.ts` itself, poking at `Meta`'s public `_mixins` and `parent` fields directly. With this split, bundles that don't import `@ember/object/mixin` get a cleaner `Meta` class — in the hello-world prod bundle the `addMixin` / `hasMixin` / `forEachMixins` identifiers go from present to fully absent, and `Mixin` references drop from 12 to 5. The methods were `@internal` and only called from `mixin.ts`, so this is a purely internal refactor. Verified: lint clean, type-checks pass, hello-world builds at 134.19 KB / 42.94 KB gzip (unchanged), classic v2-app-template tests 1/1 pass. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Two pieces of polish from the user's review: 1. The `sideEffects` field in package.json was over-broad — listing whole directories (`**/manager/**`, `**/validator/**`, etc.) when only a handful of files in those trees actually have top-level side effects. Replaced the directory globs with the explicit list of files that contain top-level calls (registrations, opcode `APPEND_OPCODES.add(...)`, `setGlobalContext`, `_backburner.on`, etc.). Hello-world stays at 134.12 KB / 42.92 KB. 2. Removed comments in the refactored files that explained the refactor itself ("extracted from X for tree-shaking", "kept separate so Y", "back-compat re-export"). That kind of context belongs in the PR description and commit messages, not the source tree. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

`opcodes.ts` previously imported `@glimmer/debug` (DebugLogger, VmSnapshot, debugOp / describeOp, opcodeMetadata, frag, etc.) at the top level and assembled the per-opcode `debugBefore`/`debugAfter` hooks inline in `AppendOpcodes`'s constructor — gated by `LOCAL_DEBUG`, so dead in production, but the imports still pulled the heavy `@glimmer/debug` graph into the bundle. Same registration pattern as the DebugRenderTree split: opcodes.ts exposes `registerDebugOpcodeSetup(setup)`; the heavy hook implementation moved to `opcodes-debug-setup.ts`, which calls the registry on import. `externs(vm)` now also requires the hooks to be registered (returns `undefined` otherwise) so dev builds that don't opt in skip the debug path entirely instead of crashing on a non-null assertion. Production hello-world holds at 134.12 KB / 42.90 KB gzip (`LOCAL_DEBUG` already eliminated the hooks there); the analysis bundle drops the `@glimmer/debug` files entirely. Verified: lint clean (after `pnpm lint:fix`), type-checks pass, hello-world builds, classic v2-app-template `pnpm test` 1/1 pass. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

`pnpm lint:fix` runs both `lint:eslint:fix` and `lint:format:fix`. I'd only been running the eslint half, so prettier formatting drift in five of my refactored files snuck through. CI's `lint:format` was the failure on the previous push. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

The `action` decorator lived inline in `@ember/object/index.ts`, which also imports `CoreObject` and `Observable` at module top — so any component that pulled `import { action } from '@ember/object'` (Input, Textarea, AbstractInput, LinkTo) dragged the full EmberObject / Observable / Mixin graph along with it. Move `action` (plus its `setupAction` helper, `BINDINGS_MAP`, and `hasProto`) to `@ember/object/action.ts`. `index.ts` re-exports it via `export { action } from './action'` so the no-barrel-imports lint autofix rewrites internal call sites to the deep path. `@ember/object/index.ts` itself loses its references to `isElementDescriptor` / `setClassicDecorator` / `ElementDescriptor` / `ExtendedMethodDecorator`, since those now live in `action.ts`. Hello-world: 134.12 KB / 42.94 KB → 133.42 KB / 42.69 KB gzip. Verified with `pnpm lint` (clean), `pnpm type-check:internals`, hello-world build, classic v2-app and v1 app smoke-test `pnpm test` (1/1 each). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Per a measurement pass, two commits had zero (or negative) effect on the hello-world prod bundle: - a0b1f09 (Move Meta mixin methods to standalone fns): bundle went from 134.17 KB → 134.19 KB (+0.02 KB). Mixin.create chain was already being tree-shaken in prod regardless. - 75761b8 (Decouple VM debug symbols/names from opcodes.ts): bundle held at 134.12 KB. LOCAL_DEBUG=false in dist/prod (and dist/dev) was already constant-folding the debug branches out, and vite was already tree-shaking the unused @glimmer/debug imports out of the smoke-test bundle. Both refactors were architecturally cleaner but pure no-ops at the bundle measurement that motivated this PR. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Lazy-register the classic-helper detection (`isClassicHelper` + `CLASSIC_HELPER_MANAGER`) via a side-effect file imported from `setup-registry.ts`, the same pattern already used for routing keywords / curly components / debug-render-tree. Removes the static import of `./helper` from `resolver.ts`, which was pulling the classic Helper class chain (FrameworkObject → CoreObject → Mixin) into the renderer's path even when the app does not use any classic helpers. hello-world bundle: 131.27 KB → 114.92 KB raw (-16.35 KB), 42.06 KB → 36.43 KB gzip (-5.63 KB). classic v2-app builds unchanged. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

@computed

The renderer-only path was statically pulling in: - observer.ts (sync + async observer flush) - chain-tags.ts (transitively, for getChainTagsForKey) - events.ts (transitively, for addListener/sendEvent) - decorator.ts (for COMPUTED_SETTERS) …even though a Glimmer-only app never installs an observer or a classic computed setter. Three independent reach points were responsible: 1. property_events.ts -> observer (sync flushSyncObservers etc.) 2. runloop/index.ts -> observer (async flushAsyncObservers) 3. property_set.ts -> decorator (COMPUTED_SETTERS WeakSet) Replaced each direct import with a registration hook (`registerObserverFlushSync` / `registerObserverDeactivationHooks`, `registerAsyncObserverFlush`, `registerComputedSetterCheck`) and moved the wire-up to a top-level side effect in `observer.ts` and `decorator.ts` themselves. Anyone importing those modules (addObserver/removeObserver, @computed, etc.) gets the registration fire as a side effect; renderer-only paths skip it. Marked observer.ts and decorator.ts as side-effect files in the ember-source `sideEffects` list so the registration calls survive tree-shaking when the modules ARE loaded. hello-world bundle: 114.92 KB -> 109.03 KB raw (-5.89 KB), 36.43 KB -> 34.44 KB gzip (-1.99 KB). classic v2-app builds and tests pass. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Adds the new side-effect-free files introduced by this PR: - @ember/-internals/runtime/lib/mixins/content-for.js (extracted hot path) - @ember/instrumentation/lib/internal-instrument.js (extracted hot path) - @ember/object/action.js (decorator extracted from @ember/object) All three appear in the "shaken" snapshots (dev + prod), confirming they get fully tree-shaken when imported only for side effects. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

NullVoxPopuli · 2026-05-08T06:05:58Z

📊 Size report

Tarball size — 1.2 MB → 1.2 MB

dist/dev `0.1%↑`

File	Before (Size / Brotli)	After (Size / Brotli)
Total _{(Includes all files)}	`2 MB` / `478.1 kB`	^0.1%↑`2 MB` / ^0.3%↑`479.6 kB`

Show files (24 files)

File	Before (Size / Brotli)	After (Size / Brotli)
`./packages/@ember/-internals/metal/index.js`	`4.4 kB` / `1.3 kB`	^3%↑`4.5 kB` / ^2%↑`1.3 kB`
`./packages/@ember/-internals/runtime/lib/mixins/-proxy.js`	`3.9 kB` / `1.3 kB`	^-8.95%↓`3.6 kB` / ^-10.1%↓`1.2 kB`
`./packages/@ember/-internals/runtime/lib/mixins/content-for.js`	—	`513 B` / `241 B`
`./packages/@ember/component/index.js`	`44.4 kB` / `10.2 kB`	^-97.3%↓`1.2 kB` / ^-96.2%↓`388 B`
`./packages/@ember/instrumentation/index.js`	`5.7 kB` / `1.6 kB`	^-27.9%↓`4.1 kB` / ^-25.2%↓`1.2 kB`
`./packages/@ember/instrumentation/lib/internal-instrument.js`	—	`2.1 kB` / `680 B`
`./packages/@ember/object/action.js`	—	`2.3 kB` / `739 B`
`./packages/@ember/object/index.js`	`7.3 kB` / `2 kB`	^-51%↓`3.6 kB` / ^-45.3%↓`1.1 kB`
`./packages/@ember/runloop/index.js`	`23.5 kB` / `5.1 kB`	^0.6%↑`23.6 kB` / ^0.1%↑`5.1 kB`
`./packages/shared-chunks/chain-{hash}.js`	`7.6 kB` / `2.2 kB`	^-17.6%↓`6.3 kB` / ^-17.3%↓`1.8 kB`
`./packages/shared-chunks/component-LzW-d3sh.js`	—	`77.8 kB` / `17.3 kB`
`./packages/shared-chunks/computed-{hash}.js`	`34 kB` / `7.9 kB`	^-7.89%↓`31.3 kB` / ^-7.45%↓`7.3 kB`
`./packages/shared-chunks/curly-{hash}.js`	`21.5 kB` / `5.1 kB`	^-98.1%↓`400 B` / ^-96.4%↓`181 B`
`./packages/shared-chunks/decorator-{hash}.js`	`4.7 kB` / `1.3 kB`	^3%↑`4.8 kB` / ^4%↑`1.4 kB`
`./packages/shared-chunks/index-{hash}.js`	`78.5 kB` / `19.1 kB`	^-20.4%↓`62.5 kB` / ^-34.5%↓`12.5 kB`
`./packages/shared-chunks/object-at-Bps-ulVR.js`	—	`167 B` / `95 B`
`./packages/shared-chunks/observers-{hash}.js`	`6.8 kB` / `1.6 kB`	^4%↑`7.1 kB` / ^5%↑`1.6 kB`
`./packages/shared-chunks/property_events-Dpk8DRL6.js`	—	`3.6 kB` / `1.1 kB`
`./packages/shared-chunks/property_set-{hash}.js`	`4.3 kB` / `1.4 kB`	^3%↑`4.5 kB` / ^0.8%↑`1.4 kB`
`./packages/shared-chunks/render-{hash}.js`	`55.5 kB` / `12 kB`	^0.3%↑`55.7 kB` / ^0.3%↑`12.1 kB`
`./packages/shared-chunks/setup-{hash}.js`	`2.8 kB` / `904 B`	^1,340%↑`40.1 kB` / ^1,030%↑`10.2 kB`
`./packages/shared-chunks/tags-CMTUbJMI.js`	—	`1.5 kB` / `587 B`
`./packages/shared-chunks/textarea-WSlUEr0y.js`	`14.5 kB` / `3.5 kB`	—
`./packages/shared-chunks/untouchable-{hash}.js`	`62.6 kB` / `12.2 kB`	^-6.07%↓`58.8 kB` / ^-7.68%↓`11.3 kB`

dist/prod `0.1%↑`

File	Before (Size / Brotli)	After (Size / Brotli)
Total _{(Includes all files)}	`1.8 MB` / `436.1 kB`	^0.1%↑`1.8 MB` / ^0.3%↑`437.4 kB`

Show files (25 files)

File	Before (Size / Brotli)	After (Size / Brotli)
`./packages/@ember/-internals/metal/index.js`	`4.2 kB` / `1.2 kB`	^3%↑`4.3 kB` / ^2%↑`1.3 kB`
`./packages/@ember/-internals/runtime/lib/mixins/-proxy.js`	`3 kB` / `993 B`	^-11.8%↓`2.6 kB` / ^-11.2%↓`882 B`
`./packages/@ember/-internals/runtime/lib/mixins/content-for.js`	—	`513 B` / `270 B`
`./packages/@ember/component/index.js`	`40.2 kB` / `9.4 kB`	^-97.3%↓`1.1 kB` / ^-96.1%↓`367 B`
`./packages/@ember/instrumentation/index.js`	`5.5 kB` / `1.6 kB`	^-25.8%↓`4.1 kB` / ^-22.2%↓`1.2 kB`
`./packages/@ember/instrumentation/lib/internal-instrument.js`	—	`1.9 kB` / `638 B`
`./packages/@ember/object/action.js`	—	`1.5 kB` / `566 B`
`./packages/@ember/object/index.js`	`5.7 kB` / `1.7 kB`	^-52.6%↓`2.7 kB` / ^-47%↓`910 B`
`./packages/@ember/runloop/index.js`	`22.2 kB` / `4.8 kB`	^0.6%↑`22.3 kB` / ^0.3%↑`4.9 kB`
`./packages/shared-chunks/arguments-D9HH7n3q.js`	—	`55 kB` / `10.5 kB`
`./packages/shared-chunks/chain-{hash}.js`	`6.9 kB` / `2 kB`	^-12.9%↓`6 kB` / ^-12.5%↓`1.7 kB`
`./packages/shared-chunks/component-C0g-p-9O.js`	—	`67.5 kB` / `15.5 kB`
`./packages/shared-chunks/computed-{hash}.js`	`28 kB` / `6.6 kB`	^-7.99%↓`25.8 kB` / ^-8.14%↓`6 kB`
`./packages/shared-chunks/curly-{hash}.js`	`17.2 kB` / `4.3 kB`	^-97.7%↓`400 B` / ^-95.8%↓`181 B`
`./packages/shared-chunks/debug-render-tree-CF5O4-WI.js`	`58.4 kB` / `11.3 kB`	—
`./packages/shared-chunks/decorator-{hash}.js`	`3.7 kB` / `1.1 kB`	^4%↑`3.8 kB` / ^5%↑`1.1 kB`
`./packages/shared-chunks/index-{hash}.js`	`66.5 kB` / `16.3 kB`	^-40.8%↓`39.4 kB` / ^-38.7%↓`10 kB`
`./packages/shared-chunks/object-at-Bps-ulVR.js`	—	`167 B` / `95 B`
`./packages/shared-chunks/observers-{hash}.js`	`6.8 kB` / `1.6 kB`	^4%↑`7.1 kB` / ^4%↑`1.6 kB`
`./packages/shared-chunks/property_events-CXghSZBR.js`	—	`3 kB` / `951 B`
`./packages/shared-chunks/property_set-{hash}.js`	`3 kB` / `982 B`	^5%↑`3.1 kB` / ^3%↑`1 kB`
`./packages/shared-chunks/render-{hash}.js`	`51.8 kB` / `11.2 kB`	^0.3%↑`52 kB` / ^0.3%↑`11.2 kB`
`./packages/shared-chunks/setup-{hash}.js`	`2.6 kB` / `858 B`	^1,240%↑`34.8 kB` / ^944%↑`9 kB`
`./packages/shared-chunks/tags-BYdj326j.js`	—	`982 B` / `406 B`
`./packages/shared-chunks/textarea-CHqL0Rdh.js`	`12.5 kB` / `3.2 kB`	—

smoke-tests/v2-app-hello-world-template/dist `-28.2%↓`

File	Before (Size / Brotli)	After (Size / Brotli)
`./assets/main-{hash}.js`	`151.9 kB` / `42.2 kB`	^-28.2%↓`109 kB` / ^-28.8%↓`30 kB`
Total _{(Includes all files)}	`152.2 kB` / `42.3 kB`	^-28.2%↓`109.4 kB` / ^-28.7%↓`30.2 kB`

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

NullVoxPopuli and others added 14 commits May 8, 2026 01:43

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Shrink hello-world bundle to 109 KB / 34 KB gzip / 30 KB brotli (-29%)#21387

Shrink hello-world bundle to 109 KB / 34 KB gzip / 30 KB brotli (-29%)#21387
NullVoxPopuli-ai-agent wants to merge 14 commits intoemberjs:nvp/configure-side-effectsfrom
NullVoxPopuli-ai-agent:claude/shrink-hello-world-on-side-effects

NullVoxPopuli-ai-agent commented May 8, 2026 •

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NullVoxPopuli commented May 8, 2026

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NullVoxPopuli-ai-agent commented May 8, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Pattern

Changes

1. Lazy -mount and -outlet keyword registration

2. Split classic Renderer subclass into classic-renderer.ts

3. RSVP.defer → native Promise in renderSettled

4. Curly symbols extracted to curly-symbols.ts

5. Classic Component class side-effects moved to register-curly-component.ts

6. DebugRenderTreeImpl factory moved behind a registry

7. Lighter array predicate in to-bool.ts

8. contentFor extracted to runtime/lib/mixins/content-for.ts

9. @ember/instrumentation hot path extracted to lib/internal-instrument.ts

10. @ember/object's action decorator extracted to @ember/object/action

11. Extract classic helper handler from resolver

12. Decouple property_events / runloop / property_set from the observer chain

13. sideEffects field on ember-source/package.json

What's left in the hello-world bundle

Updated tree-shakability snapshot

Test plan

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NullVoxPopuli commented May 8, 2026

📊 Size report

dist/dev 0.1%↑

dist/prod 0.1%↑

smoke-tests/v2-app-hello-world-template/dist -28.2%↓

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NullVoxPopuli-ai-agent commented May 8, 2026 •

edited

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1. Lazy `-mount` and `-outlet` keyword registration

2. Split classic `Renderer` subclass into `classic-renderer.ts`

3. `RSVP.defer` → native `Promise` in `renderSettled`

4. Curly symbols extracted to `curly-symbols.ts`

5. Classic `Component` class side-effects moved to `register-curly-component.ts`

6. `DebugRenderTreeImpl` factory moved behind a registry

7. Lighter array predicate in `to-bool.ts`

8. `contentFor` extracted to `runtime/lib/mixins/content-for.ts`

9. `@ember/instrumentation` hot path extracted to `lib/internal-instrument.ts`

10. `@ember/object`'s `action` decorator extracted to `@ember/object/action`

13. `sideEffects` field on `ember-source/package.json`

dist/dev `0.1%↑`

dist/prod `0.1%↑`

smoke-tests/v2-app-hello-world-template/dist `-28.2%↓`