Improve .origin preservation in getNarrowedTypeWorker

[Andarist]

fixes #61581

[Andarist]

This whole change aims to avoid any major functional changes.

Conceptually, it just "flips" the order of the 2 nested for loops. Before candidates were iterated and that iteration was iterating through types. With this change, it's the other way around - types are iterated and they have an inner loop through candidates. This required some changes to pull this off (like the introduction of matchedCandidates).

But why this is even needed? The goal of this code is to narrow down a type by a candidate and to truly narrow down a type a mapType or filterType have to be used because they try to preserve .origin information. By having the outer loop mapping through candidate this "merely" produced a result related to type but not one that would directly be derived from it -so the .origin had very slim chances of surviving when narrowing by a union candidate

[Andarist]

Those changes are fine - it's the candidate that had .origin on it but the goal is to preserve type's .origin and not .candidate's. The contained types here are exactly the same

[jakebailey]

@typescript-bot test it
@typescript-bot pack this

[typescript-bot]

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
pack this	✅ Started	✅ Results
test top400	✅ Started	👀 Results
user test this	✅ Started	👀 Results
run dt	✅ Started	✅ Results
perf test this faster	✅ Started	👀 Results

[typescript-bot]

Hey @jakebailey, I've packed this into an installable tgz. You can install it for testing by referencing it in your package.json like so:

{
    "devDependencies": {
        "typescript": "https://typescript.visualstudio.com/cf7ac146-d525-443c-b23c-0d58337efebc/_apis/build/builds/165021/artifacts?artifactName=tgz&fileId=24DA55CD64888D5082CC34590B0920BBC7EC3B8C66ABBE37844DA0AFCB1CBA1502&fileName=/typescript-5.9.0-insiders.20250417.tgz"
    }
}

and then running npm install.

---

There is also a playground for this build and an npm module you can use via "typescript": "npm:@typescript-deploys/pr-build@5.9.0-pr-61589-2".;

[typescript-bot]

Hey @jakebailey, the results of running the DT tests are ready.

Everything looks the same!

You can check the log here.

[typescript-bot]

@jakebailey Here are the results of running the user tests with tsc comparing main and refs/pull/61589/merge:

There were infrastructure failures potentially unrelated to your change:

• 1 instance of "Timeout"

Otherwise...

Something interesting changed - please have a look.

Details

webpack

tsconfig.types.json

• [NEW] error TS7053: Element implicitly has an 'any' type because expression of type '"type"' can't be used to index type 'Node | Node[]'.
  • lib/util/concatenate.js#L80

tsconfig.json

• [NEW] error TS7053: Element implicitly has an 'any' type because expression of type '"type"' can't be used to index type 'Node | Node[]'.
  • lib/util/concatenate.js#L80

[typescript-bot]

@jakebailey
The results of the perf run you requested are in!

Here they are:

tsc

Comparison Report - baseline..pr

Metric	baseline	pr	Delta	Best	Worst	p-value
Compiler-Unions - node (v18.15.0, x64)
Errors	34	39	🔻+5 (+14.71%)	~	~	p=0.001 n=6
Symbols	62,390	67,043	🔻+4,653 (+ 7.46%)	~	~	p=0.001 n=6
Types	50,395	51,926	+1,531 (+ 3.04%)	~	~	p=0.001 n=6
Memory used	193,619k (± 0.74%)	196,390k (± 0.72%)	+2,771k (+ 1.43%)	195,628k	199,233k	p=0.045 n=6
Parse Time	1.30s (± 0.64%)	1.30s (± 0.80%)	~	1.29s	1.32s	p=1.000 n=6
Bind Time	0.73s	0.73s	~	~	~	p=1.000 n=6
Check Time	9.75s (± 0.47%)	9.82s (± 0.28%)	+0.08s (+ 0.79%)	9.78s	9.86s	p=0.010 n=6
Emit Time	2.72s (± 1.11%)	2.70s (± 1.01%)	~	2.66s	2.72s	p=0.164 n=6
Total Time	14.50s (± 0.47%)	14.55s (± 0.37%)	~	14.47s	14.59s	p=0.170 n=6
angular-1 - node (v18.15.0, x64)
Errors	56	56	~	~	~	p=1.000 n=6
Symbols	948,670	948,673	+3 (+ 0.00%)	~	~	p=0.001 n=6
Types	410,947	410,979	+32 (+ 0.01%)	~	~	p=0.001 n=6
Memory used	1,224,351k (± 0.01%)	1,224,211k (± 0.00%)	-140k (- 0.01%)	1,224,172k	1,224,311k	p=0.008 n=6
Parse Time	6.62s (± 0.77%)	6.66s (± 0.97%)	~	6.54s	6.71s	p=0.171 n=6
Bind Time	1.88s (± 0.62%)	1.89s (± 0.33%)	~	1.88s	1.90s	p=0.179 n=6
Check Time	31.93s (± 0.20%)	31.94s (± 0.38%)	~	31.76s	32.11s	p=0.629 n=6
Emit Time	15.24s (± 0.63%)	15.30s (± 0.78%)	~	15.14s	15.48s	p=0.520 n=6
Total Time	55.68s (± 0.25%)	55.79s (± 0.45%)	~	55.42s	56.11s	p=0.298 n=6
mui-docs - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	2,360,029	2,360,029	~	~	~	p=1.000 n=6
Types	868,081	868,081	~	~	~	p=1.000 n=6
Memory used	2,314,243k (± 0.00%)	2,314,254k (± 0.00%)	~	2,314,166k	2,314,359k	p=0.873 n=6
Parse Time	10.55s (± 0.39%)	10.56s (± 0.20%)	~	10.54s	10.60s	p=0.809 n=6
Bind Time	2.68s (± 0.28%)	2.70s (± 1.27%)	~	2.64s	2.74s	p=0.062 n=6
Check Time	84.41s (± 2.77%)	83.57s (± 0.43%)	~	82.88s	83.84s	p=1.000 n=6
Emit Time	0.37s (± 3.60%)	0.38s (± 1.46%)	~	0.37s	0.38s	p=0.228 n=6
Total Time	98.01s (± 2.39%)	97.22s (± 0.35%)	~	96.59s	97.49s	p=0.688 n=6
self-build-src - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	1,228,025	1,228,173	+148 (+ 0.01%)	~	~	p=0.001 n=6
Types	267,258	267,341	+83 (+ 0.03%)	~	~	p=0.001 n=6
Memory used	2,360,870k (± 0.03%)	2,360,816k (± 0.01%)	~	2,360,685k	2,361,078k	p=0.575 n=6
Parse Time	5.17s (± 0.74%)	5.20s (± 1.26%)	~	5.12s	5.32s	p=0.630 n=6
Bind Time	1.80s (± 0.50%)	1.80s (± 0.96%)	~	1.77s	1.82s	p=0.681 n=6
Check Time	35.37s (± 0.34%)	35.43s (± 0.89%)	~	35.19s	36.05s	p=0.810 n=6
Emit Time	2.98s (± 1.92%)	2.99s (± 1.42%)	~	2.91s	3.03s	p=0.871 n=6
Total Time	45.32s (± 0.33%)	45.42s (± 0.87%)	~	45.07s	46.20s	p=0.689 n=6
self-build-src-public-api - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	1,228,025	1,228,173	+148 (+ 0.01%)	~	~	p=0.001 n=6
Types	267,258	267,341	+83 (+ 0.03%)	~	~	p=0.001 n=6
Memory used	2,427,915k (± 0.02%)	2,427,797k (± 0.03%)	~	2,426,789k	2,428,388k	p=0.810 n=6
Parse Time	5.45s (± 0.88%)	5.45s (± 1.06%)	~	5.40s	5.55s	p=0.689 n=6
Bind Time	1.81s (± 1.28%)	1.81s (± 1.07%)	~	1.78s	1.83s	p=1.000 n=6
Check Time	35.43s (± 0.63%)	35.35s (± 0.27%)	~	35.23s	35.46s	p=0.936 n=6
Emit Time	3.07s (± 1.77%)	3.06s (± 1.04%)	~	3.02s	3.11s	p=0.872 n=6
Total Time	45.77s (± 0.60%)	45.69s (± 0.21%)	~	45.59s	45.84s	p=0.471 n=6
self-compiler - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	263,403	263,529	+126 (+ 0.05%)	~	~	p=0.001 n=6
Types	107,094	107,158	+64 (+ 0.06%)	~	~	p=0.001 n=6
Memory used	441,739k (± 0.01%)	442,029k (± 0.01%)	+290k (+ 0.07%)	441,952k	442,122k	p=0.005 n=6
Parse Time	3.55s (± 0.87%)	3.55s (± 0.29%)	~	3.54s	3.57s	p=0.871 n=6
Bind Time	1.32s (± 0.63%)	1.32s (± 1.48%)	~	1.31s	1.36s	p=0.445 n=6
Check Time	19.01s (± 0.33%)	19.07s (± 0.51%)	~	18.95s	19.20s	p=0.685 n=6
Emit Time	1.53s (± 1.28%)	1.53s (± 1.09%)	~	1.51s	1.55s	p=0.744 n=6
Total Time	25.42s (± 0.23%)	25.48s (± 0.38%)	~	25.34s	25.61s	p=0.296 n=6
ts-pre-modules - node (v18.15.0, x64)
Errors	71	73	+2 (+ 2.82%)	~	~	p=0.001 n=6
Symbols	225,981	227,646	+1,665 (+ 0.74%)	~	~	p=0.001 n=6
Types	94,356	95,227	+871 (+ 0.92%)	~	~	p=0.001 n=6
Memory used	371,274k (± 0.02%)	372,867k (± 0.02%)	+1,593k (+ 0.43%)	372,801k	372,970k	p=0.005 n=6
Parse Time	2.89s (± 1.26%)	2.90s (± 0.89%)	~	2.86s	2.94s	p=0.623 n=6
Bind Time	1.59s (± 0.77%)	1.60s (± 1.61%)	~	1.58s	1.64s	p=0.868 n=6
Check Time	16.47s (± 0.56%)	16.59s (± 0.45%)	+0.12s (+ 0.76%)	16.46s	16.67s	p=0.045 n=6
Emit Time	0.00s (±244.70%)	0.00s	~	~	~	p=0.405 n=6
Total Time	20.95s (± 0.38%)	21.09s (± 0.53%)	~	20.89s	21.20s	p=0.065 n=6
vscode - node (v18.15.0, x64)
Errors	4	4	~	~	~	p=1.000 n=6
Symbols	3,361,603	3,361,604	+1 (+ 0.00%)	~	~	p=0.001 n=6
Types	1,139,020	1,139,024	+4 (+ 0.00%)	~	~	p=0.001 n=6
Memory used	3,419,409k (± 0.03%)	3,419,219k (± 0.00%)	~	3,419,109k	3,419,328k	p=0.575 n=6
Parse Time	14.60s (± 0.36%)	14.61s (± 0.36%)	~	14.56s	14.70s	p=0.871 n=6
Bind Time	4.85s (± 3.34%)	4.70s (± 0.33%)	~	4.68s	4.72s	p=0.124 n=6
Check Time	92.75s (± 3.06%)	92.14s (± 1.52%)	~	91.16s	94.95s	p=1.000 n=6
Emit Time	29.78s (± 1.65%)	29.52s (± 0.58%)	~	29.36s	29.83s	p=0.336 n=6
Total Time	141.97s (± 2.32%)	140.97s (± 0.93%)	~	139.97s	143.58s	p=0.521 n=6
webpack - node (v18.15.0, x64)
Errors	2	2	~	~	~	p=1.000 n=6
Symbols	316,035	316,035	~	~	~	p=1.000 n=6
Types	140,050	140,050	~	~	~	p=1.000 n=6
Memory used	470,878k (± 0.03%)	470,780k (± 0.01%)	~	470,721k	470,846k	p=0.298 n=6
Parse Time	5.15s (± 0.47%)	5.16s (± 0.53%)	~	5.12s	5.19s	p=0.806 n=6
Bind Time	2.25s (± 1.55%)	2.25s (± 0.92%)	~	2.22s	2.27s	p=0.871 n=6
Check Time	25.83s (± 0.28%)	25.72s (± 0.30%)	~	25.65s	25.84s	p=0.077 n=6
Emit Time	0.00s	0.00s	~	~	~	p=1.000 n=6
Total Time	33.24s (± 0.32%)	33.12s (± 0.30%)	~	33.03s	33.29s	p=0.075 n=6
xstate-main - node (v18.15.0, x64)
Errors	5	5	~	~	~	p=1.000 n=6
Symbols	568,548	568,549	+1 (+ 0.00%)	~	~	p=0.001 n=6
Types	190,459	190,460	+1 (+ 0.00%)	~	~	p=0.001 n=6
Memory used	498,508k (± 0.02%)	498,504k (± 0.04%)	~	498,120k	498,692k	p=0.575 n=6
Parse Time	4.18s (± 0.65%)	4.19s (± 0.36%)	~	4.18s	4.22s	p=0.746 n=6
Bind Time	1.50s (± 0.69%)	1.51s (± 1.00%)	~	1.48s	1.52s	p=0.161 n=6
Check Time	25.08s (± 2.41%)	25.12s (± 2.73%)	~	24.69s	26.51s	p=0.810 n=6
Emit Time	0.00s	0.00s	~	~	~	p=1.000 n=6
Total Time	30.76s (± 1.91%)	30.82s (± 2.23%)	~	30.38s	32.21s	p=0.688 n=6

System info unknown

Hosts

• node (v18.15.0, x64)

Scenarios

• Compiler-Unions - node (v18.15.0, x64)
• angular-1 - node (v18.15.0, x64)
• mui-docs - node (v18.15.0, x64)
• self-build-src - node (v18.15.0, x64)
• self-build-src-public-api - node (v18.15.0, x64)
• self-compiler - node (v18.15.0, x64)
• ts-pre-modules - node (v18.15.0, x64)
• vscode - node (v18.15.0, x64)
• webpack - node (v18.15.0, x64)
• xstate-main - node (v18.15.0, x64)

Benchmark	Name	Iterations
Current	pr	6
Baseline	baseline	6

Developer Information:

Download Benchmarks

[Andarist]

Damn, those perf results are not great 😢 But first I'll have to investigate the webpack change

[typescript-bot]

@jakebailey Here are the results of running the top 400 repos with tsc comparing main and refs/pull/61589/merge:

Something interesting changed - please have a look.

Details

apollographql/apollo-client

1 of 13 projects failed to build with the old tsc and were ignored

tsconfig.json

• error TS2339: Property 'kind' does not exist on type 'ASTNode | readonly ASTNode[]'.
  • src/utilities/graphql/transform.ts#L182
• error TS2339: Property 'kind' does not exist on type 'FieldNode | FragmentSpreadNode | InlineFragmentNode | DirectiveNode | ArgumentNode | NameNode | ... 36 more ... | readonly ASTNode[]'.
  • src/utilities/graphql/transform.ts#L186

src/tsconfig.json

• error TS2339: Property 'kind' does not exist on type 'ASTNode | readonly ASTNode[]'.
  • src/utilities/graphql/transform.ts#L182
• error TS2339: Property 'kind' does not exist on type 'FieldNode | FragmentSpreadNode | InlineFragmentNode | DirectiveNode | ArgumentNode | NameNode | ... 36 more ... | readonly ASTNode[]'.
  • src/utilities/graphql/transform.ts#L186

resend/react-email

36 of 39 projects failed to build with the old tsc and were ignored

packages/render/tsconfig.json

• error TS2339: Property 'type' does not exist on type 'Doc[] | DocCommand'.
  • packages/render/src/shared/utils/pretty.ts#L26
• error TS2339: Property 'type' does not exist on type 'Doc[] | BreakParent | Cursor | IfBreak | IndentIfBreak | Line | LineSuffixBoundary | Trim'.
  • packages/render/src/shared/utils/pretty.ts#L51
• error TS2322: Type '{ breakContents: Doc; flatContents: Doc; length: number; toString(): string; toLocaleString(): string; toLocaleString(locales: string | string[], options?: (NumberFormatOptions & DateTimeFormatOptions) | undefined): string; ... 37 more ...; [Symbol.unscopables]: { ...; }; } | ... 6 more ... | { ...; }' is not assignable to type 'Doc'.
  • packages/render/src/shared/utils/pretty.ts#L54
• error TS2339: Property 'breakContents' does not exist on type 'Doc[] | BreakParent | Cursor | IfBreak | IndentIfBreak | Line | LineSuffixBoundary | Trim'.
  • packages/render/src/shared/utils/pretty.ts#L54
• error TS2339: Property 'flatContents' does not exist on type 'Doc[] | BreakParent | Cursor | IfBreak | IndentIfBreak | Line | LineSuffixBoundary | Trim'.
  • packages/render/src/shared/utils/pretty.ts#L55
• error TS2345: Argument of type 'string | Doc[] | BreakParent | Cursor | IfBreak | IndentIfBreak | Line | LineSuffixBoundary | Trim' is not assignable to parameter of type 'string | DocCommand'.
  • packages/render/src/shared/utils/pretty.ts#L60

TanStack/query

79 of 118 projects failed to build with the old tsc and were ignored

packages/eslint-plugin-query/tsconfig.prod.json

• error TS2345: Argument of type 'ClassBody | TSEnumBody | TSInterfaceBody | TSModuleBlock | Expression | Statement | Statement[] | TypeElement[] | ClassElement[] | ProgramStatement[]' is not assignable to parameter of type 'Node'.
  • packages/eslint-plugin-query/src/utils/ast-utils.ts#L331 in packages/eslint-plugin-query/tsconfig.prod.json
• error TS2345: Argument of type 'Expression | Statement | Statement[]' is not assignable to parameter of type 'Node'.
  • packages/eslint-plugin-query/src/utils/ast-utils.ts#L341 in packages/eslint-plugin-query/tsconfig.prod.json

packages/eslint-plugin-query/tsconfig.json

• error TS2345: Argument of type 'ClassBody | TSEnumBody | TSInterfaceBody | TSModuleBlock | Expression | Statement | Statement[] | TypeElement[] | ClassElement[] | ProgramStatement[]' is not assignable to parameter of type 'Node'.
  • packages/eslint-plugin-query/src/utils/ast-utils.ts#L331 in packages/eslint-plugin-query/tsconfig.json
• error TS2345: Argument of type 'Expression | Statement | Statement[]' is not assignable to parameter of type 'Node'.
  • packages/eslint-plugin-query/src/utils/ast-utils.ts#L341 in packages/eslint-plugin-query/tsconfig.json

[Andarist]

@jakebailey could you rerun the tests here?

[jakebailey]

@typescript-bot test it
@typescript-bot pack this

[typescript-bot]

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
pack this	✅ Started	✅ Results
test top400	✅ Started	✅ Results
user test this	✅ Started	✅ Results
run dt	✅ Started	✅ Results
perf test this faster	✅ Started	👀 Results

[typescript-bot]

Hey @jakebailey, I've packed this into an installable tgz. You can install it for testing by referencing it in your package.json like so:

{
    "devDependencies": {
        "typescript": "https://typescript.visualstudio.com/cf7ac146-d525-443c-b23c-0d58337efebc/_apis/build/builds/165032/artifacts?artifactName=tgz&fileId=DC191BE44328575CEBE60ACECA83A2D2C1BFC93B0034E732034C342CEB4A671802&fileName=/typescript-5.9.0-insiders.20250418.tgz"
    }
}

and then running npm install.

---

There is also a playground for this build and an npm module you can use via "typescript": "npm:@typescript-deploys/pr-build@5.9.0-pr-61589-11".;

[typescript-bot]

Hey @jakebailey, the results of running the DT tests are ready.

Everything looks the same!

You can check the log here.

[typescript-bot]

@jakebailey Here are the results of running the user tests with tsc comparing main and refs/pull/61589/merge:

There were infrastructure failures potentially unrelated to your change:

• 1 instance of "Timeout"

Otherwise...

Everything looks good!

[typescript-bot]

@jakebailey
The results of the perf run you requested are in!

Here they are:

tsc

Comparison Report - baseline..pr

Metric	baseline	pr	Delta	Best	Worst	p-value
Compiler-Unions - node (v18.15.0, x64)
Errors	34	35	+1 (+ 2.94%)	~	~	p=0.001 n=6
Symbols	62,390	62,396	+6 (+ 0.01%)	~	~	p=0.001 n=6
Types	50,395	50,411	+16 (+ 0.03%)	~	~	p=0.001 n=6
Memory used	193,546k (± 0.76%)	192,063k (± 0.99%)	~	190,814k	194,617k	p=0.230 n=6
Parse Time	1.31s (± 0.62%)	1.31s (± 0.39%)	~	1.31s	1.32s	p=0.114 n=6
Bind Time	0.73s	0.73s	~	~	~	p=1.000 n=6
Check Time	9.74s (± 0.27%)	9.62s (± 0.13%)	-0.12s (- 1.21%)	9.61s	9.64s	p=0.005 n=6
Emit Time	2.73s (± 0.68%)	2.72s (± 0.77%)	~	2.69s	2.74s	p=0.418 n=6
Total Time	14.51s (± 0.28%)	14.38s (± 0.08%)	-0.13s (- 0.87%)	14.36s	14.39s	p=0.005 n=6
angular-1 - node (v18.15.0, x64)
Errors	56	56	~	~	~	p=1.000 n=6
Symbols	948,670	948,671	+1 (+ 0.00%)	~	~	p=0.001 n=6
Types	410,947	410,963	+16 (+ 0.00%)	~	~	p=0.001 n=6
Memory used	1,224,382k (± 0.00%)	1,224,179k (± 0.01%)	-203k (- 0.02%)	1,224,091k	1,224,353k	p=0.008 n=6
Parse Time	6.59s (± 0.94%)	6.64s (± 0.65%)	~	6.56s	6.68s	p=0.195 n=6
Bind Time	1.89s (± 0.44%)	1.88s (± 0.43%)	-0.02s (- 0.97%)	1.87s	1.89s	p=0.013 n=6
Check Time	32.01s (± 0.58%)	31.83s (± 0.25%)	~	31.70s	31.94s	p=0.093 n=6
Emit Time	15.21s (± 0.66%)	15.18s (± 0.64%)	~	15.06s	15.30s	p=0.810 n=6
Total Time	55.70s (± 0.53%)	55.54s (± 0.31%)	~	55.32s	55.81s	p=0.378 n=6
mui-docs - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	2,360,780	2,360,780	~	~	~	p=1.000 n=6
Types	868,446	868,446	~	~	~	p=1.000 n=6
Memory used	2,316,189k (± 0.00%)	2,316,210k (± 0.00%)	~	2,316,181k	2,316,247k	p=0.230 n=6
Parse Time	10.55s (± 0.44%)	10.53s (± 0.29%)	~	10.49s	10.57s	p=0.335 n=6
Bind Time	2.66s (± 1.72%)	2.69s (± 1.07%)	~	2.65s	2.73s	p=0.518 n=6
Check Time	83.75s (± 1.59%)	83.88s (± 1.41%)	~	82.63s	85.41s	p=0.810 n=6
Emit Time	0.36s (± 3.77%)	0.36s (± 3.51%)	~	0.35s	0.38s	p=0.510 n=6
Total Time	97.33s (± 1.36%)	97.46s (± 1.21%)	~	96.21s	98.99s	p=0.936 n=6
self-build-src - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	1,228,025	1,228,173	+148 (+ 0.01%)	~	~	p=0.001 n=6
Types	267,258	267,341	+83 (+ 0.03%)	~	~	p=0.001 n=6
Memory used	2,360,702k (± 0.02%)	2,360,960k (± 0.02%)	~	2,360,429k	2,361,618k	p=0.689 n=6
Parse Time	5.21s (± 0.94%)	5.20s (± 1.01%)	~	5.15s	5.27s	p=0.521 n=6
Bind Time	1.80s (± 0.78%)	1.80s (± 0.42%)	~	1.79s	1.81s	p=0.867 n=6
Check Time	35.39s (± 0.30%)	35.38s (± 0.26%)	~	35.24s	35.51s	p=0.810 n=6
Emit Time	3.00s (± 0.93%)	3.01s (± 1.61%)	~	2.97s	3.10s	p=1.000 n=6
Total Time	45.40s (± 0.21%)	45.40s (± 0.18%)	~	45.30s	45.52s	p=0.936 n=6
self-build-src-public-api - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	1,228,025	1,228,173	+148 (+ 0.01%)	~	~	p=0.001 n=6
Types	267,258	267,341	+83 (+ 0.03%)	~	~	p=0.001 n=6
Memory used	2,793,946k (±14.29%)	3,038,523k (± 9.77%)	🔻+244,577k (+ 8.75%)	2,431,756k	3,160,235k	p=0.020 n=6
Parse Time	6.89s (± 2.66%)	7.01s (± 1.02%)	~	6.92s	7.12s	p=0.471 n=6
Bind Time	2.17s (± 1.48%)	2.17s (± 1.60%)	~	2.13s	2.23s	p=0.808 n=6
Check Time	42.91s (± 0.47%)	42.92s (± 0.39%)	~	42.73s	43.13s	p=0.936 n=6
Emit Time	3.65s (± 4.43%)	3.55s (± 0.92%)	~	3.50s	3.57s	p=0.229 n=6
Total Time	55.62s (± 0.27%)	55.64s (± 0.37%)	~	55.37s	55.83s	p=0.936 n=6
self-compiler - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	263,403	263,529	+126 (+ 0.05%)	~	~	p=0.001 n=6
Types	107,094	107,158	+64 (+ 0.06%)	~	~	p=0.001 n=6
Memory used	441,742k (± 0.02%)	441,990k (± 0.01%)	+248k (+ 0.06%)	441,937k	442,065k	p=0.005 n=6
Parse Time	3.54s (± 1.04%)	3.55s (± 0.79%)	~	3.50s	3.58s	p=0.413 n=6
Bind Time	1.33s (± 0.82%)	1.32s (± 0.68%)	~	1.31s	1.33s	p=0.149 n=6
Check Time	18.99s (± 0.47%)	19.07s (± 0.43%)	~	18.98s	19.18s	p=0.336 n=6
Emit Time	1.53s (± 1.35%)	1.54s (± 0.54%)	~	1.53s	1.55s	p=0.868 n=6
Total Time	25.39s (± 0.33%)	25.47s (± 0.37%)	~	25.35s	25.59s	p=0.149 n=6
ts-pre-modules - node (v18.15.0, x64)
Errors	71	71	~	~	~	p=1.000 n=6
Symbols	225,981	226,095	+114 (+ 0.05%)	~	~	p=0.001 n=6
Types	94,356	94,456	+100 (+ 0.11%)	~	~	p=0.001 n=6
Memory used	371,261k (± 0.01%)	371,610k (± 0.02%)	+349k (+ 0.09%)	371,487k	371,737k	p=0.005 n=6
Parse Time	2.90s (± 1.37%)	2.91s (± 0.80%)	~	2.88s	2.95s	p=0.808 n=6
Bind Time	1.60s (± 1.00%)	1.62s (± 2.34%)	~	1.55s	1.65s	p=0.169 n=6
Check Time	16.54s (± 0.34%)	16.58s (± 0.68%)	~	16.46s	16.74s	p=0.688 n=6
Emit Time	0.00s	0.00s	~	~	~	p=1.000 n=6
Total Time	21.05s (± 0.17%)	21.12s (± 0.40%)	~	21.02s	21.23s	p=0.198 n=6
vscode - node (v18.15.0, x64)
Errors	4	4	~	~	~	p=1.000 n=6
Symbols	3,362,714	3,362,715	+1 (+ 0.00%)	~	~	p=0.001 n=6
Types	1,139,426	1,139,430	+4 (+ 0.00%)	~	~	p=0.001 n=6
Memory used	3,420,807k (± 0.00%)	3,420,725k (± 0.00%)	~	3,420,622k	3,420,840k	p=0.066 n=6
Parse Time	12.12s (± 0.26%)	12.08s (± 0.21%)	~	12.05s	12.12s	p=0.063 n=6
Bind Time	3.90s (± 0.38%)	3.93s (± 0.54%)	~	3.90s	3.96s	p=0.052 n=6
Check Time	77.71s (± 0.19%)	77.79s (± 0.46%)	~	77.24s	78.33s	p=0.575 n=6
Emit Time	25.02s (± 0.22%)	25.01s (± 0.35%)	~	24.94s	25.18s	p=0.521 n=6
Total Time	118.75s (± 0.11%)	118.82s (± 0.33%)	~	118.14s	119.35s	p=0.378 n=6
webpack - node (v18.15.0, x64)
Errors	2	2	~	~	~	p=1.000 n=6
Symbols	316,041	316,041	~	~	~	p=1.000 n=6
Types	140,052	140,052	~	~	~	p=1.000 n=6
Memory used	470,767k (± 0.03%)	470,857k (± 0.02%)	~	470,652k	470,979k	p=0.298 n=6
Parse Time	5.17s (± 0.56%)	5.14s (± 0.91%)	~	5.06s	5.18s	p=0.257 n=6
Bind Time	2.27s (± 0.62%)	2.27s (± 0.92%)	~	2.24s	2.29s	p=0.935 n=6
Check Time	25.80s (± 0.18%)	25.80s (± 0.37%)	~	25.71s	25.93s	p=0.748 n=6
Emit Time	0.00s (±154.76%)	0.00s	~	~	~	p=0.174 n=6
Total Time	33.24s (± 0.17%)	33.21s (± 0.30%)	~	33.09s	33.36s	p=0.575 n=6
xstate-main - node (v18.15.0, x64)
Errors	5	5	~	~	~	p=1.000 n=6
Symbols	568,548	568,549	+1 (+ 0.00%)	~	~	p=0.001 n=6
Types	190,459	190,460	+1 (+ 0.00%)	~	~	p=0.001 n=6
Memory used	498,527k (± 0.03%)	498,507k (± 0.02%)	~	498,380k	498,576k	p=0.575 n=6
Parse Time	4.17s (± 0.45%)	4.17s (± 0.28%)	~	4.16s	4.19s	p=0.621 n=6
Bind Time	1.51s (± 0.54%)	1.50s (± 0.70%)	~	1.48s	1.51s	p=0.078 n=6
Check Time	25.00s (± 2.14%)	25.07s (± 1.59%)	~	24.76s	25.61s	p=0.296 n=6
Emit Time	0.00s	0.00s	~	~	~	p=1.000 n=6
Total Time	30.69s (± 1.73%)	30.74s (± 1.31%)	~	30.42s	31.27s	p=0.629 n=6

System info unknown

Hosts

• node (v18.15.0, x64)

Scenarios

• Compiler-Unions - node (v18.15.0, x64)
• angular-1 - node (v18.15.0, x64)
• mui-docs - node (v18.15.0, x64)
• self-build-src - node (v18.15.0, x64)
• self-build-src-public-api - node (v18.15.0, x64)
• self-compiler - node (v18.15.0, x64)
• ts-pre-modules - node (v18.15.0, x64)
• vscode - node (v18.15.0, x64)
• webpack - node (v18.15.0, x64)
• xstate-main - node (v18.15.0, x64)

Benchmark	Name	Iterations
Current	pr	6
Baseline	baseline	6

Developer Information:

Download Benchmarks

[typescript-bot]

@jakebailey Here are the results of running the top 400 repos with tsc comparing main and refs/pull/61589/merge:

Everything looks good!

[Andarist]

@jakebailey could you rerun this again? I don't think this will fix the degraded performance (I'm working on that) but it would be nice to learn if the extended test suites can catch any new functional issues with the current version

[jakebailey]

@typescript-bot test it
@typescript-bot pack this

[typescript-bot]

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
pack this	✅ Started	✅ Results
test top400	✅ Started	✅ Results
user test this	✅ Started	✅ Results
run dt	✅ Started	✅ Results
perf test this faster	✅ Started	👀 Results

[typescript-bot]

Hey @jakebailey, I've packed this into an installable tgz. You can install it for testing by referencing it in your package.json like so:

{
    "devDependencies": {
        "typescript": "https://typescript.visualstudio.com/cf7ac146-d525-443c-b23c-0d58337efebc/_apis/build/builds/165038/artifacts?artifactName=tgz&fileId=C49E64C15E4422445E6375E948F8C98A365BC57BC995A2CB80EBBFEC51CD3BD302&fileName=/typescript-5.9.0-insiders.20250420.tgz"
    }
}

and then running npm install.

---

There is also a playground for this build and an npm module you can use via "typescript": "npm:@typescript-deploys/pr-build@5.9.0-pr-61589-19".;

[typescript-bot]

Hey @jakebailey, the results of running the DT tests are ready.

Everything looks the same!

You can check the log here.

[typescript-bot]

@jakebailey Here are the results of running the user tests with tsc comparing main and refs/pull/61589/merge:

There were infrastructure failures potentially unrelated to your change:

• 1 instance of "Timeout"

Otherwise...

Everything looks good!

[typescript-bot]

@jakebailey
The results of the perf run you requested are in!

Here they are:

tsc

Comparison Report - baseline..pr

Metric	baseline	pr	Delta	Best	Worst	p-value
Compiler-Unions - node (v18.15.0, x64)
Errors	34	34	~	~	~	p=1.000 n=6
Symbols	62,390	62,393	+3 (+ 0.00%)	~	~	p=0.001 n=6
Types	50,395	50,381	-14 (- 0.03%)	~	~	p=0.001 n=6
Memory used	194,151k (± 0.95%)	194,091k (± 0.96%)	~	192,853k	196,511k	p=0.128 n=6
Parse Time	1.31s (± 1.15%)	1.31s (± 0.57%)	~	1.30s	1.32s	p=0.492 n=6
Bind Time	0.73s	0.73s	~	~	~	p=1.000 n=6
Check Time	9.75s (± 0.42%)	9.82s (± 0.29%)	+0.07s (+ 0.70%)	9.78s	9.86s	p=0.019 n=6
Emit Time	2.73s (± 0.36%)	2.74s (± 1.15%)	~	2.72s	2.80s	p=0.797 n=6
Total Time	14.51s (± 0.37%)	14.59s (± 0.32%)	+0.08s (+ 0.57%)	14.53s	14.66s	p=0.030 n=6
angular-1 - node (v18.15.0, x64)
Errors	56	56	~	~	~	p=1.000 n=6
Symbols	948,670	948,672	+2 (+ 0.00%)	~	~	p=0.001 n=6
Types	410,947	410,962	+15 (+ 0.00%)	~	~	p=0.001 n=6
Memory used	1,224,357k (± 0.00%)	1,224,333k (± 0.00%)	~	1,224,258k	1,224,422k	p=0.470 n=6
Parse Time	6.62s (± 0.87%)	6.65s (± 0.60%)	~	6.58s	6.70s	p=0.569 n=6
Bind Time	1.88s (± 0.40%)	1.89s (± 0.52%)	~	1.88s	1.90s	p=0.109 n=6
Check Time	32.00s (± 0.36%)	31.97s (± 0.32%)	~	31.86s	32.12s	p=0.575 n=6
Emit Time	15.22s (± 0.64%)	15.15s (± 0.48%)	~	15.05s	15.24s	p=0.370 n=6
Total Time	55.72s (± 0.19%)	55.66s (± 0.20%)	~	55.50s	55.83s	p=0.378 n=6
mui-docs - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	2,360,830	2,360,830	~	~	~	p=1.000 n=6
Types	868,468	868,468	~	~	~	p=1.000 n=6
Memory used	2,315,960k (± 0.00%)	2,316,065k (± 0.01%)	~	2,315,937k	2,316,558k	p=1.000 n=6
Parse Time	8.73s (± 0.47%)	8.76s (± 0.35%)	~	8.73s	8.81s	p=0.197 n=6
Bind Time	2.19s (± 0.94%)	2.19s (± 0.50%)	~	2.18s	2.21s	p=0.933 n=6
Check Time	69.84s (± 0.36%)	69.87s (± 0.36%)	~	69.53s	70.30s	p=0.872 n=6
Emit Time	0.30s (± 2.75%)	0.30s (± 2.98%)	~	0.29s	0.31s	p=0.550 n=6
Total Time	81.07s (± 0.34%)	81.13s (± 0.32%)	~	80.82s	81.58s	p=0.748 n=6
self-build-src - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	1,228,025	1,228,022	-3 (- 0.00%)	~	~	p=0.001 n=6
Types	267,258	267,246	-12 (- 0.00%)	~	~	p=0.001 n=6
Memory used	2,972,231k (±10.03%)	2,607,030k (±14.47%)	~	2,361,757k	3,095,546k	p=0.298 n=6
Parse Time	6.68s (± 1.72%)	6.59s (± 1.53%)	~	6.47s	6.74s	p=0.128 n=6
Bind Time	2.15s (± 1.02%)	2.18s (± 1.94%)	~	2.12s	2.24s	p=0.227 n=6
Check Time	42.96s (± 0.43%)	42.99s (± 0.99%)	~	42.45s	43.38s	p=0.688 n=6
Emit Time	3.45s (± 1.33%)	3.52s (± 2.79%)	~	3.41s	3.64s	p=0.471 n=6
Total Time	55.25s (± 0.55%)	55.28s (± 0.96%)	~	54.61s	55.79s	p=0.575 n=6
self-build-src-public-api - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	1,228,025	1,228,022	-3 (- 0.00%)	~	~	p=0.001 n=6
Types	267,258	267,246	-12 (- 0.00%)	~	~	p=0.001 n=6
Memory used	2,427,654k (± 0.01%)	2,427,484k (± 0.03%)	~	2,426,659k	2,428,243k	p=0.575 n=6
Parse Time	5.46s (± 1.25%)	5.48s (± 1.43%)	~	5.41s	5.59s	p=0.688 n=6
Bind Time	1.81s (± 0.65%)	1.82s (± 0.54%)	~	1.81s	1.83s	p=0.082 n=6
Check Time	35.45s (± 0.77%)	35.35s (± 0.14%)	~	35.28s	35.40s	p=0.810 n=6
Emit Time	3.04s (± 1.30%)	3.06s (± 2.04%)	~	2.99s	3.16s	p=0.521 n=6
Total Time	45.76s (± 0.72%)	45.70s (± 0.21%)	~	45.59s	45.80s	p=0.936 n=6
self-compiler - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	263,403	263,399	-4 (- 0.00%)	~	~	p=0.001 n=6
Types	107,094	107,077	-17 (- 0.02%)	~	~	p=0.001 n=6
Memory used	441,746k (± 0.01%)	441,786k (± 0.01%)	~	441,719k	441,860k	p=0.298 n=6
Parse Time	3.56s (± 1.03%)	3.55s (± 1.43%)	~	3.50s	3.63s	p=0.376 n=6
Bind Time	1.33s (± 0.67%)	1.32s (± 0.68%)	~	1.31s	1.33s	p=0.113 n=6
Check Time	18.97s (± 0.37%)	19.05s (± 0.36%)	~	18.97s	19.18s	p=0.053 n=6
Emit Time	1.54s (± 1.58%)	1.54s (± 1.19%)	~	1.52s	1.57s	p=0.513 n=6
Total Time	25.40s (± 0.26%)	25.46s (± 0.44%)	~	25.36s	25.67s	p=0.469 n=6
ts-pre-modules - node (v18.15.0, x64)
Errors	71	71	~	~	~	p=1.000 n=6
Symbols	225,981	225,980	-1 (- 0.00%)	~	~	p=0.001 n=6
Types	94,356	94,356	~	~	~	p=1.000 n=6
Memory used	371,269k (± 0.04%)	371,230k (± 0.01%)	~	371,179k	371,305k	p=0.630 n=6
Parse Time	2.90s (± 0.83%)	2.90s (± 1.17%)	~	2.85s	2.94s	p=1.000 n=6
Bind Time	1.61s (± 1.44%)	1.60s (± 1.60%)	~	1.58s	1.64s	p=0.461 n=6
Check Time	16.50s (± 0.30%)	16.55s (± 0.33%)	~	16.47s	16.62s	p=0.077 n=6
Emit Time	0.00s	0.00s	~	~	~	p=1.000 n=6
Total Time	21.01s (± 0.32%)	21.05s (± 0.41%)	~	20.93s	21.14s	p=0.470 n=6
vscode - node (v18.15.0, x64)
Errors	4	4	~	~	~	p=1.000 n=6
Symbols	3,364,573	3,364,574	+1 (+ 0.00%)	~	~	p=0.001 n=6
Types	1,140,065	1,140,069	+4 (+ 0.00%)	~	~	p=0.001 n=6
Memory used	3,422,246k (± 0.01%)	3,422,398k (± 0.01%)	~	3,421,949k	3,422,626k	p=0.471 n=6
Parse Time	14.61s (± 0.43%)	14.81s (± 3.18%)	~	14.53s	15.76s	p=0.689 n=6
Bind Time	4.67s (± 0.55%)	4.71s (± 1.06%)	~	4.65s	4.79s	p=0.107 n=6
Check Time	93.00s (± 3.44%)	94.02s (± 3.12%)	~	90.49s	97.92s	p=0.810 n=6
Emit Time	28.74s (± 6.69%)	28.47s (± 9.87%)	~	24.92s	31.03s	p=0.378 n=6
Total Time	141.02s (± 1.44%)	142.01s (± 2.55%)	~	139.27s	148.17s	p=0.936 n=6
webpack - node (v18.15.0, x64)
Errors	2	2	~	~	~	p=1.000 n=6
Symbols	316,041	316,041	~	~	~	p=1.000 n=6
Types	140,052	140,052	~	~	~	p=1.000 n=6
Memory used	470,893k (± 0.02%)	470,799k (± 0.03%)	~	470,667k	471,008k	p=0.173 n=6
Parse Time	5.16s (± 0.72%)	5.18s (± 0.66%)	~	5.12s	5.22s	p=0.332 n=6
Bind Time	2.26s (± 0.78%)	2.24s (± 0.94%)	~	2.21s	2.27s	p=0.054 n=6
Check Time	25.79s (± 0.47%)	25.82s (± 0.41%)	~	25.70s	25.97s	p=0.747 n=6
Emit Time	0.00s	0.00s (±244.70%)	~	0.00s	0.01s	p=0.405 n=6
Total Time	33.21s (± 0.40%)	33.24s (± 0.29%)	~	33.13s	33.40s	p=0.574 n=6
xstate-main - node (v18.15.0, x64)
Errors	5	5	~	~	~	p=1.000 n=6
Symbols	570,517	570,518	+1 (+ 0.00%)	~	~	p=0.001 n=6
Types	191,417	191,418	+1 (+ 0.00%)	~	~	p=0.001 n=6
Memory used	500,777k (± 0.03%)	500,877k (± 0.03%)	~	500,604k	501,055k	p=0.173 n=6
Parse Time	4.31s (± 0.58%)	4.31s (± 0.73%)	~	4.28s	4.37s	p=0.936 n=6
Bind Time	1.53s (± 1.12%)	1.53s (± 0.87%)	~	1.51s	1.54s	p=0.867 n=6
Check Time	25.15s (± 2.07%)	25.00s (± 1.36%)	~	24.78s	25.68s	p=1.000 n=6
Emit Time	0.00s	0.00s (±244.70%)	~	0.00s	0.01s	p=0.405 n=6
Total Time	30.99s (± 1.72%)	30.84s (± 1.09%)	~	30.58s	31.51s	p=0.936 n=6

System info unknown

Hosts

• node (v18.15.0, x64)

Scenarios

• Compiler-Unions - node (v18.15.0, x64)
• angular-1 - node (v18.15.0, x64)
• mui-docs - node (v18.15.0, x64)
• self-build-src - node (v18.15.0, x64)
• self-build-src-public-api - node (v18.15.0, x64)
• self-compiler - node (v18.15.0, x64)
• ts-pre-modules - node (v18.15.0, x64)
• vscode - node (v18.15.0, x64)
• webpack - node (v18.15.0, x64)
• xstate-main - node (v18.15.0, x64)

Benchmark	Name	Iterations
Current	pr	6
Baseline	baseline	6

Developer Information:

Download Benchmarks

[typescript-bot]

@jakebailey Here are the results of running the top 400 repos with tsc comparing main and refs/pull/61589/merge:

Everything looks good!

[Andarist]

The last results were better but there is still some slight increase in check type of Compiler-Unions. I have pushed out now a version that might address this. Could you rerun tests for me again here @jakebailey 🙏 ? :)

[jakebailey]

@typescript-bot test it

[typescript-bot]

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
test top400	✅ Started	✅ Results
user test this	✅ Started	✅ Results
run dt	✅ Started	✅ Results
perf test this faster	✅ Started	👀 Results

[typescript-bot]

@jakebailey Here are the results of running the user tests with tsc comparing main and refs/pull/61589/merge:

There were infrastructure failures potentially unrelated to your change:

• 1 instance of "Timeout"

Otherwise...

Everything looks good!

[typescript-bot]

Hey @jakebailey, the results of running the DT tests are ready.

Everything looks the same!

You can check the log here.

[typescript-bot]

@jakebailey
The results of the perf run you requested are in!

Here they are:

tsc

Comparison Report - baseline..pr

Metric	baseline	pr	Delta	Best	Worst	p-value
Compiler-Unions - node (v18.15.0, x64)
Errors	34	34	~	~	~	p=1.000 n=6
Symbols	62,390	62,395	+5 (+ 0.01%)	~	~	p=0.001 n=6
Types	50,395	50,410	+15 (+ 0.03%)	~	~	p=0.001 n=6
Memory used	195,967k (± 0.82%)	194,815k (± 0.78%)	-1,152k (- 0.59%)	191,719k	195,540k	p=0.045 n=6
Parse Time	1.60s (± 1.60%)	1.59s (± 1.24%)	~	1.57s	1.63s	p=0.511 n=6
Bind Time	0.87s (± 1.87%)	0.89s (± 1.56%)	~	0.87s	0.90s	p=0.254 n=6
Check Time	11.74s (± 0.38%)	11.79s (± 0.20%)	+0.05s (+ 0.43%)	11.76s	11.82s	p=0.045 n=6
Emit Time	3.41s (± 4.67%)	3.37s (± 3.98%)	~	3.26s	3.57s	p=0.686 n=6
Total Time	17.63s (± 0.97%)	17.64s (± 0.79%)	~	17.52s	17.82s	p=1.000 n=6
angular-1 - node (v18.15.0, x64)
Errors	56	56	~	~	~	p=1.000 n=6
Symbols	948,670	948,681	+11 (+ 0.00%)	~	~	p=0.001 n=6
Types	410,947	410,967	+20 (+ 0.00%)	~	~	p=0.001 n=6
Memory used	1,224,373k (± 0.00%)	1,230,127k (± 0.00%)	+5,754k (+ 0.47%)	1,230,067k	1,230,165k	p=0.005 n=6
Parse Time	6.63s (± 0.71%)	6.67s (± 0.27%)	~	6.64s	6.69s	p=0.104 n=6
Bind Time	1.89s (± 0.88%)	1.88s (± 1.10%)	~	1.87s	1.92s	p=0.676 n=6
Check Time	32.01s (± 0.45%)	32.41s (± 0.47%)	+0.40s (+ 1.25%)	32.25s	32.61s	p=0.005 n=6
Emit Time	15.21s (± 0.95%)	15.27s (± 0.40%)	~	15.19s	15.35s	p=0.630 n=6
Total Time	55.73s (± 0.42%)	56.24s (± 0.30%)	+0.51s (+ 0.91%)	56.04s	56.44s	p=0.005 n=6
mui-docs - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	2,360,852	2,360,852	~	~	~	p=1.000 n=6
Types	868,468	868,468	~	~	~	p=1.000 n=6
Memory used	2,315,968k (± 0.00%)	2,315,993k (± 0.00%)	~	2,315,943k	2,316,055k	p=0.630 n=6
Parse Time	8.72s (± 0.33%)	8.74s (± 0.29%)	~	8.71s	8.77s	p=0.333 n=6
Bind Time	2.19s (± 0.61%)	2.19s (± 0.47%)	~	2.18s	2.21s	p=1.000 n=6
Check Time	69.88s (± 0.38%)	70.16s (± 0.28%)	~	69.87s	70.45s	p=0.066 n=6
Emit Time	0.30s (± 2.75%)	0.30s	~	~	~	p=0.290 n=6
Total Time	81.08s (± 0.31%)	81.40s (± 0.23%)	+0.31s (+ 0.38%)	81.11s	81.65s	p=0.045 n=6
self-build-src - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	1,228,025	1,228,052	+27 (+ 0.00%)	~	~	p=0.001 n=6
Types	267,258	267,249	-9 (- 0.00%)	~	~	p=0.001 n=6
Memory used	2,360,355k (± 0.01%)	2,360,694k (± 0.02%)	~	2,359,860k	2,361,479k	p=0.230 n=6
Parse Time	5.22s (± 0.85%)	5.20s (± 0.80%)	~	5.16s	5.28s	p=0.469 n=6
Bind Time	1.80s (± 0.84%)	1.80s (± 0.57%)	~	1.78s	1.81s	p=0.867 n=6
Check Time	35.34s (± 0.24%)	35.44s (± 0.07%)	+0.10s (+ 0.28%)	35.40s	35.47s	p=0.013 n=6
Emit Time	3.01s (± 0.78%)	3.00s (± 1.98%)	~	2.92s	3.08s	p=1.000 n=6
Total Time	45.36s (± 0.25%)	45.45s (± 0.11%)	~	45.36s	45.50s	p=0.128 n=6
self-build-src-public-api - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	1,228,025	1,228,052	+27 (+ 0.00%)	~	~	p=0.001 n=6
Types	267,258	267,249	-9 (- 0.00%)	~	~	p=0.001 n=6
Memory used	2,428,151k (± 0.01%)	2,427,930k (± 0.02%)	~	2,427,101k	2,428,549k	p=0.575 n=6
Parse Time	5.43s (± 0.61%)	5.48s (± 0.82%)	~	5.40s	5.53s	p=0.066 n=6
Bind Time	1.81s (± 0.54%)	1.81s (± 0.89%)	~	1.78s	1.83s	p=1.000 n=6
Check Time	35.47s (± 0.60%)	35.55s (± 0.97%)	~	35.19s	36.01s	p=0.873 n=6
Emit Time	3.06s (± 0.96%)	3.06s (± 0.56%)	~	3.04s	3.08s	p=1.000 n=6
Total Time	45.78s (± 0.52%)	45.89s (± 0.79%)	~	45.47s	46.38s	p=0.521 n=6
self-compiler - node (v18.15.0, x64)
Errors	0	0	~	~	~	p=1.000 n=6
Symbols	263,403	263,426	+23 (+ 0.01%)	~	~	p=0.001 n=6
Types	107,094	107,082	-12 (- 0.01%)	~	~	p=0.001 n=6
Memory used	441,728k (± 0.01%)	442,353k (± 0.25%)	+624k (+ 0.14%)	441,805k	444,649k	p=0.008 n=6
Parse Time	3.55s (± 1.09%)	3.54s (± 0.90%)	~	3.49s	3.57s	p=0.420 n=6
Bind Time	1.31s (± 1.12%)	1.32s (± 0.64%)	~	1.31s	1.33s	p=0.867 n=6
Check Time	18.93s (± 0.45%)	19.02s (± 0.58%)	~	18.93s	19.22s	p=0.229 n=6
Emit Time	1.54s (± 1.16%)	1.53s (± 1.52%)	~	1.49s	1.55s	p=1.000 n=6
Total Time	25.33s (± 0.45%)	25.40s (± 0.48%)	~	25.29s	25.63s	p=0.336 n=6
ts-pre-modules - node (v18.15.0, x64)
Errors	71	71	~	~	~	p=1.000 n=6
Symbols	225,981	225,980	-1 (- 0.00%)	~	~	p=0.001 n=6
Types	94,356	94,356	~	~	~	p=1.000 n=6
Memory used	371,326k (± 0.04%)	371,506k (± 0.07%)	~	371,278k	371,894k	p=0.128 n=6
Parse Time	2.88s (± 1.24%)	2.92s (± 0.42%)	+0.04s (+ 1.22%)	2.90s	2.93s	p=0.042 n=6
Bind Time	1.59s (± 0.62%)	1.60s (± 1.02%)	~	1.58s	1.62s	p=0.737 n=6
Check Time	16.50s (± 0.24%)	16.55s (± 0.37%)	~	16.44s	16.60s	p=0.092 n=6
Emit Time	0.00s (±244.70%)	0.00s	~	~	~	p=0.405 n=6
Total Time	20.97s (± 0.25%)	21.07s (± 0.26%)	+0.09s (+ 0.45%)	20.99s	21.12s	p=0.037 n=6
vscode - node (v18.15.0, x64)
Errors	4	4	~	~	~	p=1.000 n=6
Symbols	3,364,906	3,364,908	+2 (+ 0.00%)	~	~	p=0.001 n=6
Types	1,140,149	1,140,154	+5 (+ 0.00%)	~	~	p=0.001 n=6
Memory used	3,422,997k (± 0.01%)	3,422,791k (± 0.00%)	~	3,422,702k	3,422,858k	p=0.078 n=6
Parse Time	18.19s (± 0.45%)	18.25s (± 2.75%)	~	17.96s	19.27s	p=0.149 n=6
Bind Time	5.78s (± 0.53%)	5.77s (± 0.39%)	~	5.75s	5.81s	p=0.936 n=6
Check Time	115.08s (± 4.87%)	113.40s (± 2.51%)	~	111.09s	118.35s	p=0.936 n=6
Emit Time	33.29s (± 9.40%)	35.30s (± 5.28%)	~	31.51s	36.37s	p=0.471 n=6
Total Time	172.33s (± 2.13%)	172.73s (± 1.10%)	~	170.82s	175.21s	p=0.261 n=6
webpack - node (v18.15.0, x64)
Errors	2	2	~	~	~	p=1.000 n=6
Symbols	316,147	316,147	~	~	~	p=1.000 n=6
Types	140,126	140,126	~	~	~	p=1.000 n=6
Memory used	470,850k (± 0.04%)	470,953k (± 0.02%)	~	470,798k	471,051k	p=0.230 n=6
Parse Time	4.17s (± 1.04%)	4.15s (± 1.25%)	~	4.06s	4.20s	p=0.808 n=6
Bind Time	1.82s (± 1.46%)	1.82s (± 0.83%)	~	1.80s	1.84s	p=0.743 n=6
Check Time	20.80s (± 0.45%)	20.80s (± 0.36%)	~	20.68s	20.89s	p=1.000 n=6
Emit Time	0.00s (±154.76%)	0.00s (±154.76%)	~	0.00s	0.01s	p=1.000 n=6
Total Time	26.80s (± 0.41%)	26.77s (± 0.26%)	~	26.69s	26.88s	p=0.748 n=6
xstate-main - node (v18.15.0, x64)
Errors	5	5	~	~	~	p=1.000 n=6
Symbols	570,517	570,518	+1 (+ 0.00%)	~	~	p=0.001 n=6
Types	191,417	191,418	+1 (+ 0.00%)	~	~	p=0.001 n=6
Memory used	500,820k (± 0.04%)	500,953k (± 0.01%)	~	500,850k	501,000k	p=0.092 n=6
Parse Time	4.31s (± 0.45%)	4.32s (± 0.35%)	~	4.30s	4.34s	p=0.623 n=6
Bind Time	1.52s (± 0.99%)	1.54s (± 0.96%)	+0.02s (+ 1.43%)	1.52s	1.56s	p=0.040 n=6
Check Time	25.11s (± 2.48%)	24.90s (± 0.32%)	~	24.82s	25.03s	p=1.000 n=6
Emit Time	0.00s	0.00s	~	~	~	p=1.000 n=6
Total Time	30.94s (± 2.02%)	30.76s (± 0.28%)	~	30.64s	30.89s	p=0.688 n=6

System info unknown

Hosts

• node (v18.15.0, x64)

Scenarios

• Compiler-Unions - node (v18.15.0, x64)
• angular-1 - node (v18.15.0, x64)
• mui-docs - node (v18.15.0, x64)
• self-build-src - node (v18.15.0, x64)
• self-build-src-public-api - node (v18.15.0, x64)
• self-compiler - node (v18.15.0, x64)
• ts-pre-modules - node (v18.15.0, x64)
• vscode - node (v18.15.0, x64)
• webpack - node (v18.15.0, x64)
• xstate-main - node (v18.15.0, x64)

Benchmark	Name	Iterations
Current	pr	6
Baseline	baseline	6

Developer Information:

Download Benchmarks

[typescript-bot]

@jakebailey Here are the results of running the top 400 repos with tsc comparing main and refs/pull/61589/merge:

Everything looks good!