Remove some IE11 support (Symbols) by NullVoxPopuli · Pull Request #21079 · emberjs/ember.js

NullVoxPopuli · 2026-02-08T21:26:07Z

We dropped IE11 long ago, and forgot to clean this up

bench results are unchanged

duration phase no difference [-114ms to 80ms]
renderEnd phase no difference [-3ms to 2ms]
render1000Items1End phase no difference [-6ms to 22ms]
clearItems1End phase no difference [0ms to 2ms]
render1000Items2End phase estimated improvement -1ms [-17ms to 0ms] OR -0.22% [-7.18% to -0.02%]
clearItems2End phase no difference [0ms to 0ms]
render5000Items1End phase no difference [-43ms to 17ms]
clearManyItems1End phase no difference [-3ms to 7ms]
render5000Items2End phase no difference [-51ms to 33ms]
clearManyItems2End phase no difference [-4ms to 2ms]
render1000Items3End phase no difference [0ms to 0ms]
append1000Items1End phase no difference [-16ms to 17ms]
append1000Items2End phase no difference [-16ms to 33ms]
updateEvery10thItem1End phase no difference [0ms to 16ms]
updateEvery10thItem2End phase no difference [0ms to 0ms]
selectFirstRow1End phase no difference [0ms to 0ms]
selectSecondRow1End phase no difference [0ms to 0ms]
removeFirstRow1End phase no difference [0ms to 16ms]
removeSecondRow1End phase no difference [0ms to 16ms]
swapRows1End phase no difference [0ms to 0ms]
swapRows2End phase no difference [0ms to 0ms]
clearItems4End phase no difference [0ms to 0ms]
paint phase no difference [0ms to 0ms]

artifact-2.pdf

NullVoxPopuli · 2026-02-08T21:29:46Z

packages/@ember/-internals/utils/lib/symbol.ts

-// This code exists for that, and as a fallback in IE11. In general, prefer
-// `symbol` below when creating a new symbol.
-export function enumerableSymbol(debugName: string): string {
-  // TODO: Investigate using platform symbols, but we do not


github-actions · 2026-02-08T21:30:34Z

Estimated Asset Sizes

Diff

--- main/out.txt	2026-02-17 19:37:18.000000000 +0000
+++ pr/./pr-22263188055/out.txt	2026-02-21 19:48:52.000000000 +0000
@@ -1,46 +1,46 @@
 ╔═══════╤═══════════╤═══════════╗
 ║       │ Min       │ Gzip      ║
 ╟───────┼───────────┼───────────╢
-║ Total │ 351.99 KB │ 203.84 KB ║
+║ Total │ 351.71 KB │ 203.75 KB ║
 ╚═══════╧═══════════╧═══════════╝
 
 ╔══════════════════════╤═══════════╤═══════════╗
 ║ @ember/*             │ Min       │ Gzip      ║
 ╟──────────────────────┼───────────┼───────────╢
-║ Total                │ 313.39 KB │ 181.91 KB ║
+║ Total                │ 313.12 KB │ 181.77 KB ║
 ╟──────────────────────┼───────────┼───────────╢
-║ -internals           │ 36.65 KB  │ 26.22 KB  ║
+║ -internals           │ 36.58 KB  │ 26.05 KB  ║
 ║ application          │ 13.23 KB  │ 8.05 KB   ║
-║ array                │ 13.01 KB  │ 7.46 KB   ║
+║ array                │ 13.01 KB  │ 7.58 KB   ║
 ║ canary-features      │ 304 B     │ 389 B     ║
-║ component            │ 2.05 KB   │ 1.64 KB   ║
-║ controller           │ 1.96 KB   │ 1.41 KB   ║
-║ debug                │ 11.69 KB  │ 8.12 KB   ║
+║ component            │ 2.05 KB   │ 1.6 KB    ║
+║ controller           │ 1.9 KB    │ 1.41 KB   ║
+║ debug                │ 11.69 KB  │ 8.14 KB   ║
 ║ deprecated-features  │ 31 B      │ 77 B      ║
 ║ destroyable          │ 561 B     │ 383 B     ║
 ║ enumerable           │ 259 B     │ 387 B     ║
-║ helper               │ 1.08 KB   │ 811 B     ║
+║ helper               │ 1.08 KB   │ 829 B     ║
 ║ instrumentation      │ 2.43 KB   │ 1.79 KB   ║
-║ modifier             │ 1.22 KB   │ 965 B     ║
-║ object               │ 35.94 KB  │ 22.16 KB  ║
+║ modifier             │ 1.22 KB   │ 963 B     ║
+║ object               │ 35.8 KB   │ 21.98 KB  ║
 ║ owner                │ 159 B     │ 178 B     ║
-║ renderer             │ 630 B     │ 487 B     ║
-║ routing              │ 59.3 KB   │ 34.12 KB  ║
-║ runloop              │ 2.36 KB   │ 1.5 KB    ║
-║ service              │ 1 KB      │ 845 B     ║
-║ template             │ 654 B     │ 541 B     ║
+║ renderer             │ 630 B     │ 500 B     ║
+║ routing              │ 59.3 KB   │ 34.17 KB  ║
+║ runloop              │ 2.36 KB   │ 1.45 KB   ║
+║ service              │ 1 KB      │ 867 B     ║
+║ template             │ 654 B     │ 537 B     ║
 ║ template-compilation │ 429 B     │ 366 B     ║
-║ template-compiler    │ 123.08 KB │ 59.45 KB  ║
+║ template-compiler    │ 123.08 KB │ 59.47 KB  ║
 ║ template-factory     │ 370 B     │ 374 B     ║
 ║ test                 │ 923 B     │ 627 B     ║
-║ utils                │ 4.11 KB   │ 3.6 KB    ║
+║ utils                │ 4.11 KB   │ 3.62 KB   ║
 ║ version              │ 55 B      │ 131 B     ║
 ╚══════════════════════╧═══════════╧═══════════╝
 
 ╔═════════════════╤══════════╤══════════╗
 ║ @glimmer/*      │ Min      │ Gzip     ║
 ╟─────────────────┼──────────┼──────────╢
-║ Total           │ 38.6 KB  │ 21.94 KB ║
+║ Total           │ 38.6 KB  │ 21.98 KB ║
 ╟─────────────────┼──────────┼──────────╢
 ║ destroyable     │ 2.77 KB  │ 1.39 KB  ║
 ║ encoder         │ 81 B     │ 171 B    ║
@@ -53,7 +53,7 @@
 ║ program         │ 252 B    │ 301 B    ║
 ║ reference       │ 548 B    │ 531 B    ║
 ║ runtime         │ 10.32 KB │ 5.32 KB  ║
-║ tracking        │ 1.34 KB  │ 1.16 KB  ║
+║ tracking        │ 1.34 KB  │ 1.21 KB  ║
 ║ util            │ 1.94 KB  │ 1.68 KB  ║
 ║ validator       │ 15.75 KB │ 6.96 KB  ║
 ║ vm              │ 495 B    │ 569 B    ║

Details

This PR main

╔═══════╤═══════════╤═══════════╗
║       │ Min       │ Gzip      ║
╟───────┼───────────┼───────────╢
║ Total │ 351.71 KB │ 203.75 KB ║
╚═══════╧═══════════╧═══════════╝

╔══════════════════════╤═══════════╤═══════════╗
║ @ember/*             │ Min       │ Gzip      ║
╟──────────────────────┼───────────┼───────────╢
║ Total                │ 313.12 KB │ 181.77 KB ║
╟──────────────────────┼───────────┼───────────╢
║ -internals           │ 36.58 KB  │ 26.05 KB  ║
║ application          │ 13.23 KB  │ 8.05 KB   ║
║ array                │ 13.01 KB  │ 7.58 KB   ║
║ canary-features      │ 304 B     │ 389 B     ║
║ component            │ 2.05 KB   │ 1.6 KB    ║
║ controller           │ 1.9 KB    │ 1.41 KB   ║
║ debug                │ 11.69 KB  │ 8.14 KB   ║
║ deprecated-features  │ 31 B      │ 77 B      ║
║ destroyable          │ 561 B     │ 383 B     ║
║ enumerable           │ 259 B     │ 387 B     ║
║ helper               │ 1.08 KB   │ 829 B     ║
║ instrumentation      │ 2.43 KB   │ 1.79 KB   ║
║ modifier             │ 1.22 KB   │ 963 B     ║
║ object               │ 35.8 KB   │ 21.98 KB  ║
║ owner                │ 159 B     │ 178 B     ║
║ renderer             │ 630 B     │ 500 B     ║
║ routing              │ 59.3 KB   │ 34.17 KB  ║
║ runloop              │ 2.36 KB   │ 1.45 KB   ║
║ service              │ 1 KB      │ 867 B     ║
║ template             │ 654 B     │ 537 B     ║
║ template-compilation │ 429 B     │ 366 B     ║
║ template-compiler    │ 123.08 KB │ 59.47 KB  ║
║ template-factory     │ 370 B     │ 374 B     ║
║ test                 │ 923 B     │ 627 B     ║
║ utils                │ 4.11 KB   │ 3.62 KB   ║
║ version              │ 55 B      │ 131 B     ║
╚══════════════════════╧═══════════╧═══════════╝

╔═════════════════╤══════════╤══════════╗
║ @glimmer/*      │ Min      │ Gzip     ║
╟─────────────────┼──────────┼──────────╢
║ Total           │ 38.6 KB  │ 21.98 KB ║
╟─────────────────┼──────────┼──────────╢
║ destroyable     │ 2.77 KB  │ 1.39 KB  ║
║ encoder         │ 81 B     │ 171 B    ║
║ env             │ 38 B     │ 87 B     ║
║ global-context  │ 886 B    │ 545 B    ║
║ manager         │ 977 B    │ 608 B    ║
║ node            │ 175 B    │ 260 B    ║
║ opcode-compiler │ 1.11 KB  │ 894 B    ║
║ owner           │ 159 B    │ 202 B    ║
║ program         │ 252 B    │ 301 B    ║
║ reference       │ 548 B    │ 531 B    ║
║ runtime         │ 10.32 KB │ 5.32 KB  ║
║ tracking        │ 1.34 KB  │ 1.21 KB  ║
║ util            │ 1.94 KB  │ 1.68 KB  ║
║ validator       │ 15.75 KB │ 6.96 KB  ║
║ vm              │ 495 B    │ 569 B    ║
║ wire-format     │ 1.84 KB  │ 1.35 KB  ║
╚═════════════════╧══════════╧══════════╝

╔═══════╤═══════════╤═══════════╗
║       │ Min       │ Gzip      ║
╟───────┼───────────┼───────────╢
║ Total │ 351.99 KB │ 203.84 KB ║
╚═══════╧═══════════╧═══════════╝

╔══════════════════════╤═══════════╤═══════════╗
║ @ember/*             │ Min       │ Gzip      ║
╟──────────────────────┼───────────┼───────────╢
║ Total                │ 313.39 KB │ 181.91 KB ║
╟──────────────────────┼───────────┼───────────╢
║ -internals           │ 36.65 KB  │ 26.22 KB  ║
║ application          │ 13.23 KB  │ 8.05 KB   ║
║ array                │ 13.01 KB  │ 7.46 KB   ║
║ canary-features      │ 304 B     │ 389 B     ║
║ component            │ 2.05 KB   │ 1.64 KB   ║
║ controller           │ 1.96 KB   │ 1.41 KB   ║
║ debug                │ 11.69 KB  │ 8.12 KB   ║
║ deprecated-features  │ 31 B      │ 77 B      ║
║ destroyable          │ 561 B     │ 383 B     ║
║ enumerable           │ 259 B     │ 387 B     ║
║ helper               │ 1.08 KB   │ 811 B     ║
║ instrumentation      │ 2.43 KB   │ 1.79 KB   ║
║ modifier             │ 1.22 KB   │ 965 B     ║
║ object               │ 35.94 KB  │ 22.16 KB  ║
║ owner                │ 159 B     │ 178 B     ║
║ renderer             │ 630 B     │ 487 B     ║
║ routing              │ 59.3 KB   │ 34.12 KB  ║
║ runloop              │ 2.36 KB   │ 1.5 KB    ║
║ service              │ 1 KB      │ 845 B     ║
║ template             │ 654 B     │ 541 B     ║
║ template-compilation │ 429 B     │ 366 B     ║
║ template-compiler    │ 123.08 KB │ 59.45 KB  ║
║ template-factory     │ 370 B     │ 374 B     ║
║ test                 │ 923 B     │ 627 B     ║
║ utils                │ 4.11 KB   │ 3.6 KB    ║
║ version              │ 55 B      │ 131 B     ║
╚══════════════════════╧═══════════╧═══════════╝

╔═════════════════╤══════════╤══════════╗
║ @glimmer/*      │ Min      │ Gzip     ║
╟─────────────────┼──────────┼──────────╢
║ Total           │ 38.6 KB  │ 21.94 KB ║
╟─────────────────┼──────────┼──────────╢
║ destroyable     │ 2.77 KB  │ 1.39 KB  ║
║ encoder         │ 81 B     │ 171 B    ║
║ env             │ 38 B     │ 87 B     ║
║ global-context  │ 886 B    │ 545 B    ║
║ manager         │ 977 B    │ 608 B    ║
║ node            │ 175 B    │ 260 B    ║
║ opcode-compiler │ 1.11 KB  │ 894 B    ║
║ owner           │ 159 B    │ 202 B    ║
║ program         │ 252 B    │ 301 B    ║
║ reference       │ 548 B    │ 531 B    ║
║ runtime         │ 10.32 KB │ 5.32 KB  ║
║ tracking        │ 1.34 KB  │ 1.16 KB  ║
║ util            │ 1.94 KB  │ 1.68 KB  ║
║ validator       │ 15.75 KB │ 6.96 KB  ║
║ vm              │ 495 B    │ 569 B    ║
║ wire-format     │ 1.84 KB  │ 1.35 KB  ║
╚═════════════════╧══════════╧══════════╝

packages/@ember/-internals/glimmer/lib/component-managers/curly.ts

ef4 · 2026-02-20T19:51:08Z

packages/@ember/-internals/glimmer/lib/component-managers/curly.ts

-    // Set whether this component was invoked with a block
-    // (`{{#my-component}}{{/my-component}}`) or without one
-    // (`{{my-component}}`).
-    props[HAS_BLOCK] = hasBlock;


As we discussed during RFC review call, let's see whether we really need to change the assignment behavior here, because this looks potentially visible to user code.

looks like the commit history covered this:
NullVoxPopuli@3603790

as well as the comment on the new code.

As far as visibility to user code... maybe only about as much as the Symbol(OWNER) is

There is another way to manage the args and has block info without causing prototype deopts (in recent commits)

Co-authored-by: NullVoxPopuli <199018+NullVoxPopuli@users.noreply.github.com>

NullVoxPopuli · 2026-02-21T19:33:06Z

@copilot pull in the missing changes from this https://github.com/NullVoxPopuli/ember.js/pull/11/changes around the curly component manager (and consumers of that new exported function)

Copilot · 2026-02-21T19:33:14Z

@NullVoxPopuli I've opened a new pull request, #21112, to work on those changes. Once the pull request is ready, I'll request review from you.

…onent Co-authored-by: NullVoxPopuli <199018+NullVoxPopuli@users.noreply.github.com>

…manager Co-authored-by: NullVoxPopuli <199018+NullVoxPopuli@users.noreply.github.com>

Use WeakMap for curly component capturedArgs instead of symbol-keyed instance properties

NullVoxPopuli commented Feb 8, 2026

View reviewed changes

NullVoxPopuli changed the title ~~Remove some IE11 support~~ Remove some IE11 support (Symbols) Feb 8, 2026

NullVoxPopuli commented Feb 8, 2026

View reviewed changes

packages/@ember/-internals/glimmer/lib/component-managers/curly.ts Outdated Show resolved Hide resolved

NullVoxPopuli marked this pull request as ready for review February 8, 2026 22:40

NullVoxPopuli requested review from ef4 and kategengler February 8, 2026 22:41

driesdl approved these changes Feb 9, 2026

View reviewed changes

ef4 reviewed Feb 20, 2026

View reviewed changes

NullVoxPopuli and others added 8 commits February 21, 2026 19:26

Remove some IE11 support

fdb4ffd

Remove references to symbol

e6e8fe2

Remove reference to isInternalSymbol

e118e8c

Make sure ARGS and HAS_BLOCK are still acceessible (without big changes)

a6d9a57

Fix unused hasBlock parameter and TypeScript error

d181812

Co-authored-by: NullVoxPopuli <199018+NullVoxPopuli@users.noreply.github.com>

Remove unused _hasBlock parameter from create() signature

8993f33

Co-authored-by: NullVoxPopuli <199018+NullVoxPopuli@users.noreply.github.com>

Cleanup

161d86f

Restore package.json

e00d6b4

NullVoxPopuli force-pushed the nvp/remove-some-ie11-support branch from e668628 to e00d6b4 Compare February 21, 2026 19:26

Initial plan

8755878

Copilot AI mentioned this pull request Feb 21, 2026

Use WeakMap for curly component capturedArgs instead of symbol-keyed instance properties #21112

Merged

Copilot AI and others added 3 commits February 21, 2026 19:35

Use WeakMap for capturedArgs instead of symbol-keyed property on comp…

321b3fd

…onent Co-authored-by: NullVoxPopuli <199018+NullVoxPopuli@users.noreply.github.com>

Remove unused ARGS and HAS_BLOCK symbol exports from curly component …

b9ea54c

…manager Co-authored-by: NullVoxPopuli <199018+NullVoxPopuli@users.noreply.github.com>

Merge pull request #21112 from emberjs/copilot/sub-pr-21079

951600d

Use WeakMap for curly component capturedArgs instead of symbol-keyed instance properties

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Remove some IE11 support (Symbols)#21079

Remove some IE11 support (Symbols)#21079
NullVoxPopuli wants to merge 12 commits intomainfrom
nvp/remove-some-ie11-support

NullVoxPopuli commented Feb 8, 2026 •

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NullVoxPopuli commented Feb 8, 2026 •

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