[CLEANUP] Rename localAssert → assert, enable babel-plugin-debug-macros stripping by johanrd · Pull Request #21320 · emberjs/ember.js

johanrd · 2026-04-17T13:06:15Z

Renames the @glimmer/debug-util export from localAssert to assert, aligning it with the SUPPORTED_MACROS list in babel-plugin-debug-macros. This enables the existing debug macro infrastructure to automatically strip all assert() calls from @glimmer/debug-util in prod builds — the same way it already strips assert() from @ember/debug.

Motivation: Bundle size stripping

localAssert was a legacy name from when glimmer-vm was a separate repo. After the merge into ember.js, no file imports assert from both @ember/debug and @glimmer/debug-util (verified: zero collisions), making the local prefix unnecessary.

Previously, localAssert() compiled to an empty function in prod, but the call sites and their string arguments remained in the bundle as dead code — rollup could strip some calls where arguments were side-effect-free, but calls with template literals or property accesses survived. With this rename, babel-plugin-debug-macros strips all calls unconditionally.

Changes

@glimmer/debug-util/index.ts: export { default as assert } (was localAssert)
31 source files: import { assert } (was localAssert), all call sites renamed
broccoli/build-debug-macro-plugin.js: add second plugin instance for @glimmer/debug-util (assertPredicateIndex: 0, since condition is the first argument — unlike @ember/debug where description is first)
rollup.config.mjs + babel.test.config.mjs: spread the now-array plugin config

Bundle size impact

	Before	After	Delta
Prod shared-chunks	1,018,769 bytes	1,014,858 bytes	-3,911 bytes
Prod shared-chunks (brotli)	221,609 bytes	220,835 bytes	-774 bytes

The assert shared chunk (assert-*.js) is entirely eliminated — no runtime code imports it anymore.

Post-fix prod dist audit

Remaining assert() calls in prod are all from @ember/debug (not @glimmer/debug-util):

throw assert('Use constructor...') — @ember/debug pattern
(false && !(root) && assert('has root', root)) — @ember/debug macro output
assert(test, msg, options) — QUnit assert method definition (not a debug call)
//assert( — a comment in rehydrate-builder

Zero @glimmer/debug-util assert messages survive in prod. Strings like BUG: that appear are legitimate runtime throw new Error() statements, not assert leftovers.

No if (DEBUG) wrappers. No type casts. No code changes beyond the mechanical rename + build config.

Alternatives considered

Patching `babel-plugin-debug-macros

Patching babel-plugin-debug-macros to add localAssert to its SUPPORTED_MACROS list and Builder class. Rejected because the rename is cleaner, eliminates legacy naming, and requires no dependency patches.

Reproduce: pnpm build && wc -c dist/prod/packages/shared-chunks/*.js

Importing from @ember/debug instead

Would break the "standalone" parts of glimmer, did not dare to touch that

…os stripping Renames the @glimmer/debug-util export from localAssert to assert, aligning it with the SUPPORTED_MACROS list in babel-plugin-debug-macros. This enables the existing debug macro infrastructure to automatically strip all assert() calls from @glimmer/debug-util in prod builds — the same way it already strips assert() from @ember/debug. The name localAssert was a legacy artifact from when glimmer-vm was a separate repo. After the merge into ember.js, no file imports assert from both @ember/debug and @glimmer/debug-util, making the prefix unnecessary. Changes: - @glimmer/debug-util: export { default as assert } (was localAssert) - 31 source files: import { assert } (was localAssert) - broccoli/build-debug-macro-plugin.js: add second plugin instance for @glimmer/debug-util (assertPredicateIndex: 0, since condition is the first argument unlike @ember/debug where description is first) - rollup.config.mjs: spread the now-array plugin config Prod shared-chunks: 1,018,769 → 1,014,858 bytes (-3,911 bytes). No if(DEBUG) wrappers. No type casts. No code changes beyond the rename. Alternative considered: patching babel-plugin-debug-macros to add localAssert to its SUPPORTED_MACROS list. Rejected because the rename is cleaner and eliminates legacy naming.

NullVoxPopuli · 2026-04-18T03:11:37Z

📊 Package size report `-0.04%↓`

File	Before (Size / Brotli)	After (Size / Brotli)
`dist/dev/packages/shared-chunks/compiler-BKUHsnQa.js`	`177.6 kB` / `34 kB`	^0.6%↑`178.8 kB` / ^0.4%↑`34.2 kB`
`dist/dev/packages/shared-chunks/dynamic-BfDKO5NI.js`	`116.1 kB` / `23.6 kB`	^0.2%↑`116.3 kB` / ^-0.1%↓`23.5 kB`
`dist/dev/packages/shared-chunks/index-BGP1rw3B.js`	`62.7 kB` / `12.5 kB`	^218%↑`199.2 kB` / ^249%↑`43.7 kB`
`dist/prod/packages/shared-chunks/assert-CUCJBR2C.js`	`619 B` / `299 B`	—
`dist/prod/packages/shared-chunks/compiler-Dlb4hn0T.js`	`190.9 kB` / `36.4 kB`	^-1.14%↓`188.7 kB` / ^-0.94%↓`36 kB`
`dist/prod/packages/shared-chunks/fragment-D7nBU9ae.js`	`30.4 kB` / `7.4 kB`	^2%↑`30.9 kB` / ^2%↑`7.5 kB`
`dist/prod/packages/shared-chunks/index-6pnzcm45.js`	`59.8 kB` / `12.1 kB`	^-0.58%↓`59.5 kB` / ^-0.46%↓`12 kB`
`dist/prod/packages/shared-chunks/on-CLxdmpmk.js`	`96.7 kB` / `19.6 kB`	^-0.68%↓`96 kB` / ^-0.69%↓`19.4 kB`
`dist/prod/packages/shared-chunks/rehydrate-builder-CUefZL4I.js`	`15.6 kB` / `3.1 kB`	^-1.08%↓`15.4 kB` / ^-1.84%↓`3.1 kB`
`dist/prod/packages/shared-chunks/transform-resolutions-DR4GLmR2.js`	`174.2 kB` / `35.3 kB`	^-0.15%↓`173.9 kB` / ^-0.05%↓`35.3 kB`
Total _{(Includes all files)}	`5.4 MB` / `1.3 MB`	^-0.04%↓`5.3 MB` / ^-0.05%↓`1.3 MB`
Tarball size	`1.2 MB`	^-0.02%↓`1.2 MB`

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

NullVoxPopuli · 2026-04-18T03:12:43Z

The assert shared chunk (assert-*.js) is entirely eliminated

dist/prod/packages/shared-chunks/assert-CUCJBR2C.js

don't trust ai folks. always double check. lol

— no runtime code imports it anymore.

then why was it emitted? huh? :p

johanrd · 2026-04-18T06:30:37Z

@NullVoxPopuli — in the after column means file no longer emitted, doesn't it?

Can also ve verified locally:

On main (before):

  rm -rf dist && pnpm build && ls dist/prod/packages/shared-chunks/assert-*.js 2>&1                                                                                                                                                   
  # → dist/prod/packages/shared-chunks/assert-CUCJBR2C.js

find dist/prod/packages -type f -exec ls -l {} + | awk '{print $5, $NF}' | sort -k2

222 dist/prod/packages/@ember/-internals/browser-environment/index.js 20460 dist/prod/packages/@ember/-internals/container/index.js 4410 dist/prod/packages/@ember/-internals/deprecations/index.js 5457 dist/prod/packages/@ember/-internals/environment/index.js 533 dist/prod/packages/@ember/-internals/error-handling/index.js 2044 dist/prod/packages/@ember/-internals/glimmer/index.js 84 dist/prod/packages/@ember/-internals/meta/index.js 12839 dist/prod/packages/@ember/-internals/meta/lib/meta.js 3783 dist/prod/packages/@ember/-internals/metal/index.js 7334 dist/prod/packages/@ember/-internals/owner/index.js 807 dist/prod/packages/@ember/-internals/routing/index.js 682 dist/prod/packages/@ember/-internals/runtime/index.js 1400 dist/prod/packages/@ember/-internals/runtime/lib/ext/rsvp.js 2999 dist/prod/packages/@ember/-internals/runtime/lib/mixins/-proxy.js 5579 dist/prod/packages/@ember/-internals/runtime/lib/mixins/action_handler.js 913 dist/prod/packages/@ember/-internals/runtime/lib/mixins/comparable.js 1118 dist/prod/packages/@ember/-internals/runtime/lib/mixins/container_proxy.js 1277 dist/prod/packages/@ember/-internals/runtime/lib/mixins/registry_proxy.js 4519 dist/prod/packages/@ember/-internals/runtime/lib/mixins/target_action_support.js 3107 dist/prod/packages/@ember/-internals/string/index.js 516 dist/prod/packages/@ember/-internals/utility-types/index.js 2464 dist/prod/packages/@ember/-internals/utils/index.js 712 dist/prod/packages/@ember/-internals/views/index.js 71 dist/prod/packages/@ember/-internals/views/lib/compat/attrs.js 285 dist/prod/packages/@ember/-internals/views/lib/compat/fallback-view-registry.js 402 dist/prod/packages/@ember/-internals/views/lib/component_lookup.js 887 dist/prod/packages/@ember/-internals/views/lib/mixins/action_support.js 7196 dist/prod/packages/@ember/-internals/views/lib/system/event_dispatcher.js 4682 dist/prod/packages/@ember/-internals/views/lib/system/utils.js 3019 dist/prod/packages/@ember/-internals/views/lib/views/core_view.js 2530 dist/prod/packages/@ember/-internals/views/lib/views/states.js 32895 dist/prod/packages/@ember/application/index.js 14833 dist/prod/packages/@ember/application/instance.js 2005 dist/prod/packages/@ember/application/namespace.js 197 dist/prod/packages/@ember/array/-internals.js 16910 dist/prod/packages/@ember/array/index.js 936 dist/prod/packages/@ember/array/lib/make-array.js 47 dist/prod/packages/@ember/array/make.js 54 dist/prod/packages/@ember/array/mutable.js 9002 dist/prod/packages/@ember/array/proxy.js 1634 dist/prod/packages/@ember/canary-features/index.js 596 dist/prod/packages/@ember/component/helper.js 1470 dist/prod/packages/@ember/component/index.js 1453 dist/prod/packages/@ember/component/template-only.js 5484 dist/prod/packages/@ember/controller/index.js 3564 dist/prod/packages/@ember/debug/container-debug-adapter.js 15990 dist/prod/packages/@ember/debug/data-adapter.js 1156 dist/prod/packages/@ember/debug/index.js 145 dist/prod/packages/@ember/debug/lib/assert.js 807 dist/prod/packages/@ember/debug/lib/capture-render-tree.js 2254 dist/prod/packages/@ember/debug/lib/deprecate.js 158 dist/prod/packages/@ember/debug/lib/handlers.js 3028 dist/prod/packages/@ember/debug/lib/inspect.js 158 dist/prod/packages/@ember/debug/lib/testing.js 219 dist/prod/packages/@ember/debug/lib/warn.js 208 dist/prod/packages/@ember/deprecated-features/index.js 7657 dist/prod/packages/@ember/destroyable/index.js 15461 dist/prod/packages/@ember/engine/index.js 6779 dist/prod/packages/@ember/engine/instance.js 762 dist/prod/packages/@ember/engine/lib/engine-parent.js 90 dist/prod/packages/@ember/engine/parent.js 498 dist/prod/packages/@ember/enumerable/index.js 551 dist/prod/packages/@ember/enumerable/mutable.js 17567 dist/prod/packages/@ember/helper/index.js 5541 dist/prod/packages/@ember/instrumentation/index.js 1013 dist/prod/packages/@ember/modifier/index.js 986 dist/prod/packages/@ember/modifier/on.js 1424 dist/prod/packages/@ember/object/-internals.js 3918 dist/prod/packages/@ember/object/compat.js 808 dist/prod/packages/@ember/object/computed.js 26461 dist/prod/packages/@ember/object/core.js 1830 dist/prod/packages/@ember/object/evented.js 359 dist/prod/packages/@ember/object/events.js 5807 dist/prod/packages/@ember/object/index.js 419 dist/prod/packages/@ember/object/internals.js 19618 dist/prod/packages/@ember/object/lib/computed/computed_macros.js 27455 dist/prod/packages/@ember/object/lib/computed/reduce_computed_macros.js 16151 dist/prod/packages/@ember/object/mixin.js 6166 dist/prod/packages/@ember/object/observable.js 343 dist/prod/packages/@ember/object/observers.js 3886 dist/prod/packages/@ember/object/promise-proxy-mixin.js 2856 dist/prod/packages/@ember/object/proxy.js 3233 dist/prod/packages/@ember/owner/index.js 137 dist/prod/packages/@ember/reactive/collections.js 254 dist/prod/packages/@ember/reactive/index.js 611 dist/prod/packages/@ember/renderer/index.js 464 dist/prod/packages/@ember/routing/-internals.js 3644 dist/prod/packages/@ember/routing/hash-location.js 5717 dist/prod/packages/@ember/routing/history-location.js 582 dist/prod/packages/@ember/routing/index.js 816 dist/prod/packages/@ember/routing/lib/cache.js 301 dist/prod/packages/@ember/routing/lib/controller_for.js 5526 dist/prod/packages/@ember/routing/lib/dsl.js 1964 dist/prod/packages/@ember/routing/lib/generate_controller.js 944 dist/prod/packages/@ember/routing/lib/location-utils.js 153 dist/prod/packages/@ember/routing/lib/query_params.js 806 dist/prod/packages/@ember/routing/lib/router_state.js 4554 dist/prod/packages/@ember/routing/lib/routing-service.js 6909 dist/prod/packages/@ember/routing/lib/utils.js 2631 dist/prod/packages/@ember/routing/none-location.js 54645 dist/prod/packages/@ember/routing/route.js 24126 dist/prod/packages/@ember/routing/router-service.js 44779 dist/prod/packages/@ember/routing/router.js 22396 dist/prod/packages/@ember/runloop/index.js 3479 dist/prod/packages/@ember/service/index.js 920 dist/prod/packages/@ember/template-compilation/index.js 133 dist/prod/packages/@ember/template-compiler/-internal-primitives.js 105 dist/prod/packages/@ember/template-compiler/-internal-utils.js 114 dist/prod/packages/@ember/template-compiler/index.js 130 dist/prod/packages/@ember/template-compiler/lib/-internal/primitives.js 5106 dist/prod/packages/@ember/template-compiler/lib/compile-options.js 752 dist/prod/packages/@ember/template-compiler/lib/dasherize-component-name.js 1773 dist/prod/packages/@ember/template-compiler/lib/plugins/allowed-globals.js 1054 dist/prod/packages/@ember/template-compiler/lib/plugins/assert-against-attrs.js 853 dist/prod/packages/@ember/template-compiler/lib/plugins/assert-against-named-outlets.js 519 dist/prod/packages/@ember/template-compiler/lib/plugins/assert-input-helper-without-block.js 1001 dist/prod/packages/@ember/template-compiler/lib/plugins/assert-reserved-named-arguments.js 1393 dist/prod/packages/@ember/template-compiler/lib/plugins/auto-import-builtins.js 2609 dist/prod/packages/@ember/template-compiler/lib/plugins/index.js 1386 dist/prod/packages/@ember/template-compiler/lib/plugins/transform-action-syntax.js 1408 dist/prod/packages/@ember/template-compiler/lib/plugins/transform-each-in-into-each.js 1204 dist/prod/packages/@ember/template-compiler/lib/plugins/transform-each-track-array.js 1112 dist/prod/packages/@ember/template-compiler/lib/plugins/transform-in-element.js 902 dist/prod/packages/@ember/template-compiler/lib/plugins/transform-quoted-bindings-into-just-bindings.js 216 dist/prod/packages/@ember/template-compiler/lib/plugins/transform-resolutions.js 1122 dist/prod/packages/@ember/template-compiler/lib/plugins/transform-wrap-mount-and-outlet.js 1335 dist/prod/packages/@ember/template-compiler/lib/plugins/utils.js 42 dist/prod/packages/@ember/template-compiler/lib/public-api.js 42 dist/prod/packages/@ember/template-compiler/lib/runtime.js 619 dist/prod/packages/@ember/template-compiler/lib/system/calculate-location-display.js 9181 dist/prod/packages/@ember/template-compiler/lib/template.js 46 dist/prod/packages/@ember/template-compiler/runtime.js 286 dist/prod/packages/@ember/template-factory/index.js 637 dist/prod/packages/@ember/template/index.js 110 dist/prod/packages/@ember/test/adapter.js 537 dist/prod/packages/@ember/test/index.js 391 dist/prod/packages/@ember/utils/index.js 4378 dist/prod/packages/@ember/utils/lib/compare.js 1588 dist/prod/packages/@ember/utils/lib/is-equal.js 828 dist/prod/packages/@ember/utils/lib/is_blank.js 1858 dist/prod/packages/@ember/utils/lib/is_empty.js 598 dist/prod/packages/@ember/utils/lib/is_none.js 934 dist/prod/packages/@ember/utils/lib/is_present.js 3783 dist/prod/packages/@ember/utils/lib/type-of.js 61 dist/prod/packages/@ember/version/index.js 3862 dist/prod/packages/@glimmer/destroyable/index.js 790 dist/prod/packages/@glimmer/encoder/index.js 62 dist/prod/packages/@glimmer/env/index.js 3932 dist/prod/packages/@glimmer/global-context/index.js 9131 dist/prod/packages/@glimmer/manager/index.js 1502 dist/prod/packages/@glimmer/node/index.js 1274 dist/prod/packages/@glimmer/opcode-compiler/index.js 567 dist/prod/packages/@glimmer/owner/index.js 421 dist/prod/packages/@glimmer/program/index.js 5694 dist/prod/packages/@glimmer/reference/index.js 1589 dist/prod/packages/@glimmer/runtime/index.js 3981 dist/prod/packages/@glimmer/tracking/index.js 370 dist/prod/packages/@glimmer/tracking/primitives/cache/index.js 4586 dist/prod/packages/@glimmer/util/index.js 31788 dist/prod/packages/@glimmer/validator/index.js 565 dist/prod/packages/@glimmer/vm/index.js 2385 dist/prod/packages/@glimmer/wire-format/index.js 11084 dist/prod/packages/@simple-dom/document/index.js 27869 dist/prod/packages/backburner.js/index.js 5363 dist/prod/packages/dag-map/index.js 3335 dist/prod/packages/ember-template-compiler/index.js 303 dist/prod/packages/ember-testing/index.js 1125 dist/prod/packages/ember-testing/lib/adapters/adapter.js 105 dist/prod/packages/ember-testing/lib/public-api.js 547 dist/prod/packages/ember-testing/lib/test.js 714 dist/prod/packages/ember-testing/lib/test/adapter.js 409 dist/prod/packages/ember-testing/lib/test/pending_requests.js 3022 dist/prod/packages/ember-testing/lib/test/waiters.js 129 dist/prod/packages/ember/version.js 20941 dist/prod/packages/route-recognizer/index.js 55513 dist/prod/packages/router_js/index.js 326 dist/prod/packages/rsvp/index.js 2728 dist/prod/packages/shared-chunks/alias-BkT-0B1G.js 5983 dist/prod/packages/shared-chunks/api-Co-k4HVs.js 4029 dist/prod/packages/shared-chunks/args-proxy-Dl0A0YWI.js 4094 dist/prod/packages/shared-chunks/array-EwekEvId.js 1310 dist/prod/packages/shared-chunks/array-utils-CZQxrdD3.js 619 dist/prod/packages/shared-chunks/assert-CUCJBR2C.js 697 dist/prod/packages/shared-chunks/cache-qDyqAcpg.js 1451 dist/prod/packages/shared-chunks/capabilities-DGmQ_mz4.js 3408 dist/prod/packages/shared-chunks/chunk-3SQBS3Y5-Cj4eryg1.js 1663 dist/prod/packages/shared-chunks/collections-GpG8lT2g.js 190859 dist/prod/packages/shared-chunks/compiler-B9PLmPfT.js 254 dist/prod/packages/shared-chunks/computed_cache-DmYKevAP.js 7516 dist/prod/packages/shared-chunks/constants-CB3pk7dH.js 292 dist/prod/packages/shared-chunks/debug-brand-B1TWjOCH.js 3710 dist/prod/packages/shared-chunks/decorator-BdDDBUd2.js 559 dist/prod/packages/shared-chunks/dictionary-gc5gpyOG.js 22877 dist/prod/packages/shared-chunks/element-builder-DbktcGKV.js 877 dist/prod/packages/shared-chunks/flags-B9qxc-pB.js 30396 dist/prod/packages/shared-chunks/fragment-EpVz5Xuc.js 49 dist/prod/packages/shared-chunks/get-debug-name-BDxIL2Y1.js 601 dist/prod/packages/shared-chunks/has-dom-DdQORPzI.js 171971 dist/prod/packages/shared-chunks/index-BVy-auLZ.js 761 dist/prod/packages/shared-chunks/index-Cc8WmrB-.js 59835 dist/prod/packages/shared-chunks/index-nW__r2nX.js 1634 dist/prod/packages/shared-chunks/injected_property-DL3vQoFA.js 1771 dist/prod/packages/shared-chunks/invoke-BuwCkcVB.js 315 dist/prod/packages/shared-chunks/is_proxy-Cr1qlMv_.js 337 dist/prod/packages/shared-chunks/lookup-descriptor-CwcVgaLv.js 249 dist/prod/packages/shared-chunks/name-C68GLLO3.js 31881 dist/prod/packages/shared-chunks/namespace_search-Aog9nySA.js 255 dist/prod/packages/shared-chunks/object-utils-AijlD-JH.js 22524 dist/prod/packages/shared-chunks/observers-R1ZklwWy.js 96652 dist/prod/packages/shared-chunks/on-ByzWKBWe.js 4765 dist/prod/packages/shared-chunks/program-B7SJZ5NF.js 4940 dist/prod/packages/shared-chunks/program-context-BdUXf-jj.js 3040 dist/prod/packages/shared-chunks/property_set-O080KTKZ.js 310 dist/prod/packages/shared-chunks/public-api-C3KlJmEr.js 4268 dist/prod/packages/shared-chunks/reference-BNqcwZWH.js 973 dist/prod/packages/shared-chunks/registers-ylirb0dq.js 15596 dist/prod/packages/shared-chunks/rehydrate-builder-M_dh82nR.js 36284 dist/prod/packages/shared-chunks/render-DJ-BzvgU.js 63591 dist/prod/packages/shared-chunks/rsvp-CnCSY930.js 3828 dist/prod/packages/shared-chunks/serialize-builder-BpVMgrCr.js 2511 dist/prod/packages/shared-chunks/set_properties-CjsDTRey.js 2143 dist/prod/packages/shared-chunks/setup-registry-KYxkFexK.js 847 dist/prod/packages/shared-chunks/simple-cast-DCvJLSin.js 7921 dist/prod/packages/shared-chunks/super-Cm_a_cLQ.js 497 dist/prod/packages/shared-chunks/template-Dc_cBOoX.js 3723 dist/prod/packages/shared-chunks/tracked-ChVNBE2f.js 174192 dist/prod/packages/shared-chunks/transform-resolutions-C7wq_Q_c.js 17139 dist/prod/packages/shared-chunks/unrecognized-url-error-DDBwfzdm.js

After:

 rm -rf dist && pnpm build && ls dist/prod/packages/shared-chunks/assert-*.js 2>&1                                                                                                                              
  zsh: no matches found: dist/prod/packages/shared-chunks/assert-*.js

find dist/prod/packages -type f -exec ls -l {} + | awk '{print $5, $NF}' | sort -k2

222 dist/prod/packages/@ember/-internals/browser-environment/index.js 20460 dist/prod/packages/@ember/-internals/container/index.js 4410 dist/prod/packages/@ember/-internals/deprecations/index.js 5457 dist/prod/packages/@ember/-internals/environment/index.js 533 dist/prod/packages/@ember/-internals/error-handling/index.js 2044 dist/prod/packages/@ember/-internals/glimmer/index.js 84 dist/prod/packages/@ember/-internals/meta/index.js 12839 dist/prod/packages/@ember/-internals/meta/lib/meta.js 3783 dist/prod/packages/@ember/-internals/metal/index.js 7334 dist/prod/packages/@ember/-internals/owner/index.js 807 dist/prod/packages/@ember/-internals/routing/index.js 682 dist/prod/packages/@ember/-internals/runtime/index.js 1400 dist/prod/packages/@ember/-internals/runtime/lib/ext/rsvp.js 2999 dist/prod/packages/@ember/-internals/runtime/lib/mixins/-proxy.js 5579 dist/prod/packages/@ember/-internals/runtime/lib/mixins/action_handler.js 913 dist/prod/packages/@ember/-internals/runtime/lib/mixins/comparable.js 1118 dist/prod/packages/@ember/-internals/runtime/lib/mixins/container_proxy.js 1277 dist/prod/packages/@ember/-internals/runtime/lib/mixins/registry_proxy.js 4519 dist/prod/packages/@ember/-internals/runtime/lib/mixins/target_action_support.js 3107 dist/prod/packages/@ember/-internals/string/index.js 516 dist/prod/packages/@ember/-internals/utility-types/index.js 2464 dist/prod/packages/@ember/-internals/utils/index.js 712 dist/prod/packages/@ember/-internals/views/index.js 71 dist/prod/packages/@ember/-internals/views/lib/compat/attrs.js 285 dist/prod/packages/@ember/-internals/views/lib/compat/fallback-view-registry.js 402 dist/prod/packages/@ember/-internals/views/lib/component_lookup.js 887 dist/prod/packages/@ember/-internals/views/lib/mixins/action_support.js 7196 dist/prod/packages/@ember/-internals/views/lib/system/event_dispatcher.js 4682 dist/prod/packages/@ember/-internals/views/lib/system/utils.js 3019 dist/prod/packages/@ember/-internals/views/lib/views/core_view.js 2530 dist/prod/packages/@ember/-internals/views/lib/views/states.js 32895 dist/prod/packages/@ember/application/index.js 14833 dist/prod/packages/@ember/application/instance.js 2005 dist/prod/packages/@ember/application/namespace.js 197 dist/prod/packages/@ember/array/-internals.js 16910 dist/prod/packages/@ember/array/index.js 936 dist/prod/packages/@ember/array/lib/make-array.js 47 dist/prod/packages/@ember/array/make.js 54 dist/prod/packages/@ember/array/mutable.js 9002 dist/prod/packages/@ember/array/proxy.js 1634 dist/prod/packages/@ember/canary-features/index.js 596 dist/prod/packages/@ember/component/helper.js 1470 dist/prod/packages/@ember/component/index.js 1453 dist/prod/packages/@ember/component/template-only.js 5484 dist/prod/packages/@ember/controller/index.js 3564 dist/prod/packages/@ember/debug/container-debug-adapter.js 15990 dist/prod/packages/@ember/debug/data-adapter.js 1156 dist/prod/packages/@ember/debug/index.js 145 dist/prod/packages/@ember/debug/lib/assert.js 807 dist/prod/packages/@ember/debug/lib/capture-render-tree.js 2254 dist/prod/packages/@ember/debug/lib/deprecate.js 158 dist/prod/packages/@ember/debug/lib/handlers.js 3028 dist/prod/packages/@ember/debug/lib/inspect.js 158 dist/prod/packages/@ember/debug/lib/testing.js 219 dist/prod/packages/@ember/debug/lib/warn.js 208 dist/prod/packages/@ember/deprecated-features/index.js 7657 dist/prod/packages/@ember/destroyable/index.js 15461 dist/prod/packages/@ember/engine/index.js 6779 dist/prod/packages/@ember/engine/instance.js 762 dist/prod/packages/@ember/engine/lib/engine-parent.js 90 dist/prod/packages/@ember/engine/parent.js 498 dist/prod/packages/@ember/enumerable/index.js 551 dist/prod/packages/@ember/enumerable/mutable.js 17567 dist/prod/packages/@ember/helper/index.js 5541 dist/prod/packages/@ember/instrumentation/index.js 1013 dist/prod/packages/@ember/modifier/index.js 986 dist/prod/packages/@ember/modifier/on.js 1424 dist/prod/packages/@ember/object/-internals.js 3918 dist/prod/packages/@ember/object/compat.js 808 dist/prod/packages/@ember/object/computed.js 26461 dist/prod/packages/@ember/object/core.js 1830 dist/prod/packages/@ember/object/evented.js 359 dist/prod/packages/@ember/object/events.js 5807 dist/prod/packages/@ember/object/index.js 419 dist/prod/packages/@ember/object/internals.js 19618 dist/prod/packages/@ember/object/lib/computed/computed_macros.js 27455 dist/prod/packages/@ember/object/lib/computed/reduce_computed_macros.js 16151 dist/prod/packages/@ember/object/mixin.js 6166 dist/prod/packages/@ember/object/observable.js 343 dist/prod/packages/@ember/object/observers.js 3886 dist/prod/packages/@ember/object/promise-proxy-mixin.js 2856 dist/prod/packages/@ember/object/proxy.js 3233 dist/prod/packages/@ember/owner/index.js 137 dist/prod/packages/@ember/reactive/collections.js 254 dist/prod/packages/@ember/reactive/index.js 611 dist/prod/packages/@ember/renderer/index.js 464 dist/prod/packages/@ember/routing/-internals.js 3644 dist/prod/packages/@ember/routing/hash-location.js 5717 dist/prod/packages/@ember/routing/history-location.js 582 dist/prod/packages/@ember/routing/index.js 816 dist/prod/packages/@ember/routing/lib/cache.js 301 dist/prod/packages/@ember/routing/lib/controller_for.js 5526 dist/prod/packages/@ember/routing/lib/dsl.js 1964 dist/prod/packages/@ember/routing/lib/generate_controller.js 944 dist/prod/packages/@ember/routing/lib/location-utils.js 153 dist/prod/packages/@ember/routing/lib/query_params.js 806 dist/prod/packages/@ember/routing/lib/router_state.js 4554 dist/prod/packages/@ember/routing/lib/routing-service.js 6909 dist/prod/packages/@ember/routing/lib/utils.js 2631 dist/prod/packages/@ember/routing/none-location.js 54645 dist/prod/packages/@ember/routing/route.js 24126 dist/prod/packages/@ember/routing/router-service.js 44779 dist/prod/packages/@ember/routing/router.js 22396 dist/prod/packages/@ember/runloop/index.js 3479 dist/prod/packages/@ember/service/index.js 920 dist/prod/packages/@ember/template-compilation/index.js 133 dist/prod/packages/@ember/template-compiler/-internal-primitives.js 105 dist/prod/packages/@ember/template-compiler/-internal-utils.js 114 dist/prod/packages/@ember/template-compiler/index.js 130 dist/prod/packages/@ember/template-compiler/lib/-internal/primitives.js 5106 dist/prod/packages/@ember/template-compiler/lib/compile-options.js 752 dist/prod/packages/@ember/template-compiler/lib/dasherize-component-name.js 1773 dist/prod/packages/@ember/template-compiler/lib/plugins/allowed-globals.js 1054 dist/prod/packages/@ember/template-compiler/lib/plugins/assert-against-attrs.js 853 dist/prod/packages/@ember/template-compiler/lib/plugins/assert-against-named-outlets.js 519 dist/prod/packages/@ember/template-compiler/lib/plugins/assert-input-helper-without-block.js 1001 dist/prod/packages/@ember/template-compiler/lib/plugins/assert-reserved-named-arguments.js 1393 dist/prod/packages/@ember/template-compiler/lib/plugins/auto-import-builtins.js 2609 dist/prod/packages/@ember/template-compiler/lib/plugins/index.js 1386 dist/prod/packages/@ember/template-compiler/lib/plugins/transform-action-syntax.js 1408 dist/prod/packages/@ember/template-compiler/lib/plugins/transform-each-in-into-each.js 1204 dist/prod/packages/@ember/template-compiler/lib/plugins/transform-each-track-array.js 1112 dist/prod/packages/@ember/template-compiler/lib/plugins/transform-in-element.js 902 dist/prod/packages/@ember/template-compiler/lib/plugins/transform-quoted-bindings-into-just-bindings.js 216 dist/prod/packages/@ember/template-compiler/lib/plugins/transform-resolutions.js 1122 dist/prod/packages/@ember/template-compiler/lib/plugins/transform-wrap-mount-and-outlet.js 1335 dist/prod/packages/@ember/template-compiler/lib/plugins/utils.js 42 dist/prod/packages/@ember/template-compiler/lib/public-api.js 42 dist/prod/packages/@ember/template-compiler/lib/runtime.js 619 dist/prod/packages/@ember/template-compiler/lib/system/calculate-location-display.js 9181 dist/prod/packages/@ember/template-compiler/lib/template.js 46 dist/prod/packages/@ember/template-compiler/runtime.js 286 dist/prod/packages/@ember/template-factory/index.js 637 dist/prod/packages/@ember/template/index.js 110 dist/prod/packages/@ember/test/adapter.js 537 dist/prod/packages/@ember/test/index.js 391 dist/prod/packages/@ember/utils/index.js 4378 dist/prod/packages/@ember/utils/lib/compare.js 1588 dist/prod/packages/@ember/utils/lib/is-equal.js 828 dist/prod/packages/@ember/utils/lib/is_blank.js 1858 dist/prod/packages/@ember/utils/lib/is_empty.js 598 dist/prod/packages/@ember/utils/lib/is_none.js 934 dist/prod/packages/@ember/utils/lib/is_present.js 3783 dist/prod/packages/@ember/utils/lib/type-of.js 61 dist/prod/packages/@ember/version/index.js 3862 dist/prod/packages/@glimmer/destroyable/index.js 790 dist/prod/packages/@glimmer/encoder/index.js 62 dist/prod/packages/@glimmer/env/index.js 3932 dist/prod/packages/@glimmer/global-context/index.js 9131 dist/prod/packages/@glimmer/manager/index.js 1502 dist/prod/packages/@glimmer/node/index.js 1274 dist/prod/packages/@glimmer/opcode-compiler/index.js 567 dist/prod/packages/@glimmer/owner/index.js 421 dist/prod/packages/@glimmer/program/index.js 5694 dist/prod/packages/@glimmer/reference/index.js 1589 dist/prod/packages/@glimmer/runtime/index.js 3981 dist/prod/packages/@glimmer/tracking/index.js 370 dist/prod/packages/@glimmer/tracking/primitives/cache/index.js 4586 dist/prod/packages/@glimmer/util/index.js 31788 dist/prod/packages/@glimmer/validator/index.js 565 dist/prod/packages/@glimmer/vm/index.js 2385 dist/prod/packages/@glimmer/wire-format/index.js 11084 dist/prod/packages/@simple-dom/document/index.js 27869 dist/prod/packages/backburner.js/index.js 5363 dist/prod/packages/dag-map/index.js 3335 dist/prod/packages/ember-template-compiler/index.js 303 dist/prod/packages/ember-testing/index.js 1125 dist/prod/packages/ember-testing/lib/adapters/adapter.js 105 dist/prod/packages/ember-testing/lib/public-api.js 547 dist/prod/packages/ember-testing/lib/test.js 714 dist/prod/packages/ember-testing/lib/test/adapter.js 409 dist/prod/packages/ember-testing/lib/test/pending_requests.js 3022 dist/prod/packages/ember-testing/lib/test/waiters.js 129 dist/prod/packages/ember/version.js 20941 dist/prod/packages/route-recognizer/index.js 55513 dist/prod/packages/router_js/index.js 326 dist/prod/packages/rsvp/index.js 2728 dist/prod/packages/shared-chunks/alias-BLBQkche.js 5983 dist/prod/packages/shared-chunks/api-DtWa0ZaF.js 4029 dist/prod/packages/shared-chunks/args-proxy-Dl0A0YWI.js 4094 dist/prod/packages/shared-chunks/array-kVQfzrQn.js 1310 dist/prod/packages/shared-chunks/array-utils-CZQxrdD3.js 697 dist/prod/packages/shared-chunks/cache-qDyqAcpg.js 1451 dist/prod/packages/shared-chunks/capabilities-DXA-L0iT.js 3408 dist/prod/packages/shared-chunks/chunk-3SQBS3Y5-Cj4eryg1.js 1663 dist/prod/packages/shared-chunks/collections-GpG8lT2g.js 188735 dist/prod/packages/shared-chunks/compiler-CccZzVi8.js 254 dist/prod/packages/shared-chunks/computed_cache-DmYKevAP.js 7516 dist/prod/packages/shared-chunks/constants-2M371WiB.js 292 dist/prod/packages/shared-chunks/debug-brand-B1TWjOCH.js 3710 dist/prod/packages/shared-chunks/decorator-BdDDBUd2.js 559 dist/prod/packages/shared-chunks/dictionary-gc5gpyOG.js 22786 dist/prod/packages/shared-chunks/element-builder-BmLF0C-1.js 877 dist/prod/packages/shared-chunks/flags-B9qxc-pB.js 30885 dist/prod/packages/shared-chunks/fragment-D7nBU9ae.js 49 dist/prod/packages/shared-chunks/get-debug-name-BDxIL2Y1.js 601 dist/prod/packages/shared-chunks/has-dom-DdQORPzI.js 171971 dist/prod/packages/shared-chunks/index-6pnzcm45.js 761 dist/prod/packages/shared-chunks/index-Cc8WmrB-.js 59487 dist/prod/packages/shared-chunks/index-CjaDF9kC.js 1634 dist/prod/packages/shared-chunks/injected_property-CTVs5FPh.js 1771 dist/prod/packages/shared-chunks/invoke-BdJCXD-b.js 315 dist/prod/packages/shared-chunks/is_proxy-Cr1qlMv_.js 337 dist/prod/packages/shared-chunks/lookup-descriptor-CwcVgaLv.js 249 dist/prod/packages/shared-chunks/name-C68GLLO3.js 31881 dist/prod/packages/shared-chunks/namespace_search-Dcdalhj6.js 255 dist/prod/packages/shared-chunks/object-utils-AijlD-JH.js 22524 dist/prod/packages/shared-chunks/observers-tZ2aOzr4.js 95992 dist/prod/packages/shared-chunks/on-CLxdmpmk.js 4765 dist/prod/packages/shared-chunks/program-B7SJZ5NF.js 4940 dist/prod/packages/shared-chunks/program-context-DFiwaPMR.js 3040 dist/prod/packages/shared-chunks/property_set-B2sZxeCw.js 310 dist/prod/packages/shared-chunks/public-api-C3KlJmEr.js 4268 dist/prod/packages/shared-chunks/reference-BNqcwZWH.js 973 dist/prod/packages/shared-chunks/registers-ylirb0dq.js 15427 dist/prod/packages/shared-chunks/rehydrate-builder-CUefZL4I.js 36200 dist/prod/packages/shared-chunks/render-BlriW61t.js 63591 dist/prod/packages/shared-chunks/rsvp-CnCSY930.js 3828 dist/prod/packages/shared-chunks/serialize-builder-DgpXSc2Q.js 2511 dist/prod/packages/shared-chunks/set_properties-C1T46IiN.js 2143 dist/prod/packages/shared-chunks/setup-registry-DeObnZ2Z.js 847 dist/prod/packages/shared-chunks/simple-cast-DCvJLSin.js 7921 dist/prod/packages/shared-chunks/super-Cm_a_cLQ.js 497 dist/prod/packages/shared-chunks/template-Dc_cBOoX.js 3723 dist/prod/packages/shared-chunks/tracked-Cl5l4v8b.js 173931 dist/prod/packages/shared-chunks/transform-resolutions-DR4GLmR2.js 17139 dist/prod/packages/shared-chunks/unrecognized-url-error-DDBwfzdm.js

-  619 assert-CUCJBR2C.js                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
-190859 compiler-B9PLmPfT.js                                                                                                                                                                                      
+188735 compiler-CccZzVi8.js                                                                                                                                                                  
-22877 element-builder-DbktcGKV.js
+22786 element-builder-BmLF0C-1.js                                                                                                                                                                                
-30396 fragment-EpVz5Xuc.js                                                                                                                                                                                       
+30885 fragment-D7nBU9ae.js
-59835 index-nW__r2nX.js                                                                                                                                                                                          
+59487 index-CjaDF9kC.js
-96652 on-ByzWKBWe.js                                                                                                                                                                                             
+95992 on-CLxdmpmk.js
-15596 rehydrate-builder-M_dh82nR.js                                                                                                                                                                              
+15427 rehydrate-builder-CUefZL4I.js                                                                                                                                                                              
-36284 render-DJ-BzvgU.js
+36200 render-BlriW61t.js                                                                                                                                                                                         
-174192 transform-resolutions-C7wq_Q_c.js                                                                                                                                                                         
+173931 transform-resolutions-DR4GLmR2.js

Net per this migration: assert-.js −619 B, fragment-.js +489 B, ≈ −130 B (assertNever). The rest of the −3,911 B overall comes from the actual assert-call-site stripping across compiler-.js, on-.js, transform-resolutions-*.js, etc.

NullVoxPopuli · 2026-04-18T12:24:54Z

Yup, tried sleep deprived me is not better at reading that ai. Boo.

Tyty for the triple check

NullVoxPopuli · 2026-04-18T15:28:51Z

I checked this out locally to poke around in dist and it looks like these asserts were stripped from both dev and prod -- I think we'd want to keep them in dev, yea?

johanrd · 2026-04-18T19:52:47Z

@NullVoxPopuli thanks for checking that. I am not able to reproduce dev stripping, however:

Repro on each side: git checkout <branch> && rm -rf dist && pnpm build, then run the three grep/ls commands below:

Step	main (before)	PR (after)
is dev assert emitted? yes `ls -l dist/dev/packages/shared-chunks/assert-*.js`	`619 assert-CUCJBR2C.js`	`619 assert-CUCJBR2C.js`
what is the dev assert count? equal `grep -c "assert(" dist/dev/packages/shared-chunks/compiler-*.js`	`46`	`46`
how does the assert look like? `grep -n "assert(" dist/dev/packages/shared-chunks/compiler-*.js \| head -5`	`assert(roundTrip.line === line);` `assert(roundTrip.column === column);` `assert(_elseBlock.blockParams.length === 0);` `assert(tag.type === 'PathExpression', …);` `assert(tag.path.type === 'PathExpression', …);`	`(!(roundTrip.line === line) && assert(roundTrip.line === line));` `(!(roundTrip.column === column) && assert(roundTrip.column === column));` `(!(_elseBlock.blockParams.length === 0) && assert(_elseBlock.blockParams.length === 0));` `(!(tag.type === 'PathExpression') && assert(tag.type === 'PathExpression', …));` `(!(tag.path.type === 'PathExpression') && assert(tag.path.type === 'PathExpression', …));`
is prod assert emitted? not after `ls dist/prod/packages/shared-chunks/assert-*.js 2>&1`	`dist/prod/packages/shared-chunks/assert-CUCJBR2C.js`	`zsh: no matches found: dist/prod/packages/shared-chunks/assert-*.js`
what is the prod assert count? `grep -c "assert(" dist/prod/packages/shared-chunks/compiler-*.js`	`44`	`10` (the 10 residual matches are unrelated validator methods like `assert(node) {...}`; the 34-call delta is the `@glimmer/debug-util` asserts physically stripped)

Dev: same chunk, same count, same semantics. The PR just wraps each call in (!cond && assert(cond, msg)) — happy path skips the call, failing path throws exactly as before. This is babel-plugin-debug-macros doing its standard dev transform.

NullVoxPopuli · 2026-04-18T20:10:28Z

ok, bot, if you're so smart explain this:

NullVoxPopuli · 2026-04-18T20:10:57Z

make sure you delete dist before building again.

johanrd · 2026-04-19T00:07:59Z

@NullVoxPopuli okay, thanks for steps to reproduce, but i don't think this PR introduces that? assert is an empty function. In dev. On main. Already:

git checkout main && rm -rf dist && pnpm build
rep -l "A glimmer transaction was begun" dist/dev/ -r 2>&1          # → empty
cat dist/dev/packages/shared-chunks/assert-*.js                       # → empty assert body

Empty assert body on dist/dev/packages/shared-chunks/assert-CUCJBR2C.js on main:

// import Logger from './logger';

function assert(test, msg) {
}

/**
 * This constant exists to make it easier to differentiate normal logs from
 * errant console.logs. LOGGER can be used outside of LOCAL_TRACE_LOGGING checks,
 * and is meant to be used in the rare situation where a console.* call is
 * actually appropriate.
 */
const LOGGER = console;
function assertNever(value, desc = 'unexpected unreachable branch') {
  LOGGER.log('unreachable', value);
  LOGGER.log(`${desc} :: ${JSON.stringify(value)} (${value})`);
  throw new Error(`code reached unreachable`);
}

export { assert as a, assertNever as b };

Why is assert empty on main?

Asked claude why:

@glimmer/debug-util/lib/assert.ts is gated on LOCAL_DEBUG, not DEBUG:                                                                                                                                        
                  
  import { LOCAL_DEBUG } from '@glimmer/local-debug-flags';                                                                                                                                                         
  export default function assert(test, msg) {
    if (LOCAL_DEBUG) {                                                                                                                                                                                              
      if (!test) throw new Error(msg || 'assertion failure');
    }                                                                                                                                                                                                               
  }               
                                                                                                                                                                                                                    
  And LOCAL_DEBUG is:
  export const LOCAL_DEBUG = !!(import.meta.env?.VM_LOCAL_DEV && !hasFlag('disable_local_debug'));
                                                                                                  
  VM_LOCAL_DEV is only set by glimmer-vm's own dev harness — it's false in a normal pnpm build, both dev and prod. So the if (LOCAL_DEBUG) body is dead, the throw gets stripped, the msg arg has no remaining use, 
  and rollup DCEs both the string literals at call sites and the function body. You end up with:                                                                                                                    
                                                                                                                                                                                                                    
  - main's dev dist: assert(!this[TRANSACTION]); (bare call, no message) + empty assert function                                                                                                                    
  - PR's dev dist: (!(!this[TRANSACTION]) && assert(!this[TRANSACTION])); + same empty assert function
                                                                                                                                                                                                                    
  Both are functionally identical no-ops in dev. @glimmer/debug-util asserts have been no-ops in default builds for a long time — this is by design (they only fire when glimmer devs manually enable VM_LOCAL_DEV).
   The PR doesn't change that.                                                                                                                                                                                      
                                                                                                                                                                                                                    
  What the PR actually changes:
  - dev: call sites get the (!cond && assert(cond)) short-circuit wrapper. Runtime behavior unchanged (still a no-op because assert body is still empty).
  - prod: call sites + the empty assert function are fully removed. This is the bundle-size win.

NullVoxPopuli · 2026-04-19T00:15:20Z

assert is an empty function. In dev. On main.

right, and I'm challenging you... why do we not want to expose debug information to the user? Do we have a good reason to omit these assertions from both dev and prod? I'm willing to hear it <3

even in our own testing -- whenever we use the build, we miss out on this debugging that would only be available in vite-uncompiled testing

johanrd · 2026-04-19T00:28:50Z

No, and that is a very good point. (This PR does not touch that behavior – we just found out)

It looks like a consequence of glimmer-vm #1646 (Nov 2024), which predates the repo merge by ~13 months. When ember-source bumped its glimmer-vm dependency past that PR, the asserts went silent in all downstream builds. Nobody seems to have noticed because the failure mode is silence, not errors. (and no regression tests caught it)

History

@glimmer/debug-util's assert has been gated behind LOCAL_DEBUG (true in the Vite dev server, false in published builds) since 2024-11-02 — glimmer-vm PR #1646 "Streamline append VM implementation" which consolidated the previous two-function design (debugAssert + prodAssert) into one LOCAL_DEBUG-gated assert. Before that, debugAssert in @glimmer/util threw unconditionally — no DEBUG/LOCAL_DEBUG gate. Since that commit, the function body has been dead code in default builds, and rollup's tree-shaker has been removing both the body and the unused message literals at call sites. This PR doesn't change dev runtime behavior — it just strips the dead call sites and the already-empty function from prod.

Intentional?

In glimmer-vm as a standalone repo, "LOCAL_DEBUG false by default" reads naturally: if you're hacking on the VM, set VM_LOCAL_DEV; otherwise asserts stay out of your way.
The awkwardness showed up once ember-source started consuming post-1646 glimmer-vm (late 2024). Ember app devs are always on the "consumer" side of VM_LOCAL_DEV without a flag to flip, so any app code that transitively hits @glimmer/debug-util asserts gets nothing in dev — unlike @ember/debug asserts, which do fire. I don't think anyone deliberately decided "ember dev builds should skip glimmer asserts"; it was a second-order effect of 1646 landing in an ember-source release. The failure mode is silence, so nobody noticed.
The co-existence of two asserts with different dev semantics — @ember/debug (fires in dev) vs @glimmer/debug-util (doesn't) — is the awkward part. The PR's rename to assert makes that awkwardness more visible (same name, different behavior depending on import path).

What to do?

This PR is about removing unambiguously dead weight from prod — the call sites were already no-ops (if (LOCAL_DEBUG) body elided), the function body was already empty, the message literals were already stripped. Flipping the dev semantics — i.e., deciding "@glimmer/debug-util asserts should fire in ember.js dev builds" — is a legitimate and separate question . Mechanically it'd mean either:

changing the LOCAL_DEBUG gate to DEBUG inside assert.ts, or
redirecting @glimmer/debug-util's assert to @ember/debug's assert when building inside ember.js (build-config swap).
add dev mode regression tests for intentional glimmer vm errors?

NullVoxPopuli · 2026-04-19T00:51:55Z

I think we're good to move forward with this PR -- thanks for the back and forth.

If we want these errors to show up for consumers, we can do that just as easily

johanrd · 2026-04-19T00:56:25Z

@NullVoxPopuli Thanks. Worth noting: https://github.com/emberjs/ember.js/blob/main/packages/@glimmer-workspace/integration-tests/test/env-test.ts#L7-L23 has a test gated on if (DEBUG) that expects env.begin() to throw with the "A glimmer transaction was begun" message. It currently passes — but only because the integration tests run against source through Vite (VM_LOCAL_DEV=true → LOCAL_DEBUG=true). Run against a built ember-source artifact, the assert is a no-op, the throw never happens, and the test would fail. In other words, the test author already assumed DEBUG was the right gate. #1646 made LOCAL_DEBUG the actual gate, and nobody caught it because the test's execution environment happens to satisfy both flags simultaneously.

These tests should maybe be moved to smoke tests if we want them to hit for ember dev consumers if we do LOCAL_DEBUG → DEBUG in assert.ts?

NullVoxPopuli · 2026-04-19T02:06:31Z

we also test in dev mode which does catch that

NullVoxPopuli · 2026-04-19T02:08:24Z

johanrd marked this pull request as ready for review April 17, 2026 13:16

NullVoxPopuli approved these changes Apr 19, 2026

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NullVoxPopuli merged commit 58a135d into emberjs:main Apr 19, 2026
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johanrd commented Apr 17, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Motivation: Bundle size stripping

Changes

Bundle size impact

Alternatives considered

Patching `babel-plugin-debug-macros

Importing from @ember/debug instead

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NullVoxPopuli commented Apr 18, 2026

📊 Package size report -0.04%↓

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On main (before):

After:

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NullVoxPopuli commented Apr 18, 2026

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johanrd commented Apr 18, 2026

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johanrd commented Apr 19, 2026

Empty assert body on dist/dev/packages/shared-chunks/assert-CUCJBR2C.js on main:

Why is assert empty on main?

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NullVoxPopuli commented Apr 19, 2026

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History

Intentional?

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johanrd commented Apr 17, 2026 •

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📊 Package size report `-0.04%↓`

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