Combine inferences from distributive conditional types #62093

Andarist · 2025-07-20T10:52:29Z

fixes #62079

Inferring from an argument with a union type into a distributive conditional type is very likely to produce results that will end up with a signature applicability error. This can be demonstrated by this basic example:

declare class Animal { eat(): void; }
declare class Cat extends Animal { meow(): void; }
declare class Dog extends Animal { bark(): void; }

declare function test1<T>(a: T extends unknown ? { prop: T } : never): T;
declare const arg1: { prop: Dog } | { prop: Cat };

const result1 = test1(arg1); // error
const result2 = test1<Dog | Animal>(arg1); // ok

While there is an easy workaround for the above (one can provide an explicit type argument), it's not possible to do the same in situations involving generic signatures containing distributive conditional types when another conditional type infers from them.

The problem is that infer P (for example, in Parameters) can be instantiated with a union constraint of the input generic signature (so it's capable of "inferring" it) but then that signature is used by instantiateSignatureInContextOf and that can't "synthesize" the union back for the type parameter and ultimately it makes the conditional type (like Parameters) to go for its .falseType branch.

Conceptually, I'm proposing a simple extension to the existing inference algorithm - when the target is a distributive conditional type, the inferred candidates are allowed to be combined into a union. A lower priority inference removes that behavior - but the same priority inference made from a position outside of a distributive conditional type keeps its gathered candidates.

typescript-bot · 2025-07-20T10:52:42Z

Looks like you're introducing a change to the public API surface area. If this includes breaking changes, please document them on our wiki's API Breaking Changes page.

Also, please make sure @DanielRosenwasser and @RyanCavanaugh are aware of the changes, just as a heads up.

Copilot

Pull Request Overview

This PR implements a fix for TypeScript issue #62079 by combining inferences from distributive conditional types. The change modifies the type inference system to properly handle parameters that use distributive conditional types, ensuring that inferences from multiple union member distributions are correctly combined.

Adds a new DistributiveConditional inference priority flag to track distributive conditional type inferences
Modifies inference priority logic to combine distributive conditional inferences with other priorities
Updates the conditional type inference process to mark distributive conditional types with the new priority

Reviewed Changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
`src/compiler/types.ts`	Adds `DistributiveConditional` inference priority flag and includes it in combination logic
`src/compiler/checker.ts`	Implements distributive conditional inference tracking and priority combination logic
`tests/cases/compiler/genericFunctionParametersConditionalType1.ts`	Test case demonstrating the fix for distributive conditional type parameter inference
`tests/baselines/reference/genericFunctionParametersConditionalType1.types`	Expected type output showing proper union distribution in parameter types
`tests/baselines/reference/genericFunctionParametersConditionalType1.symbols`	Expected symbol resolution output for the test case

Comments suppressed due to low confidence (1)

Andarist · 2025-07-20T10:55:42Z

src/compiler/checker.ts

                            return;
                        }
-                        if (inference.priority === undefined || priority < inference.priority) {
+                        const combinedPriority = priority | (inference.individualPriority || InferencePriority.None);


I don't quite like how this turned out - I probably should move this thing to a separate InferenceInfo property (similar to topLevel) instead of shoving it into .priority.

That said, those changes would be cosmetic and wouldn't really change the idea behind this fix. In the meantime, I'd love to see what user/top tests have to say about this (cc @jakebailey )

RyanCavanaugh · 2025-07-21T18:58:09Z

@typescript-bot test it

typescript-bot · 2025-07-21T18:58:14Z

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 · 2025-07-21T19:23:01Z

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

Everything looks the same!

You can check the log here.

typescript-bot · 2025-07-21T19:24:54Z

@RyanCavanaugh Here are the results of running the user tests with tsc comparing main and refs/pull/62093/merge:

Something interesting changed - please have a look.

Details

effect

packages/effect/benchmark/tsconfig.json

[NEW] error TS2322: Type 'transformOrFail<S, SchemaClass<any, any, never> | S, FD>' is not assignable to type 'filterEffect<S, FD>'.
- packages/effect/src/Schema.ts#L3764

tsconfig.json

[NEW] error TS2322: Type 'transformOrFail<S, SchemaClass<any, any, never> | S, FD>' is not assignable to type 'filterEffect<S, FD>'.
- packages/effect/src/Schema.ts#L3764 in packages/effect/tsconfig.src.json
- packages/effect/src/Schema.ts#L3764 in packages/effect/tsconfig.build.json

tsconfig.build.json

[NEW] error TS2322: Type 'transformOrFail<S, SchemaClass<any, any, never> | S, FD>' is not assignable to type 'filterEffect<S, FD>'.
- packages/effect/src/Schema.ts#L3764 in packages/effect/tsconfig.build.json

packages/typeclass/dtslint/tsconfig.json

[NEW] error TS2322: Type 'transformOrFail<S, SchemaClass<any, any, never> | S, FD>' is not assignable to type 'filterEffect<S, FD>'.
- packages/effect/src/Schema.ts#L3764 in packages/effect/tsconfig.src.json

packages/platform/dtslint/tsconfig.json

[NEW] error TS2322: Type 'transformOrFail<S, SchemaClass<any, any, never> | S, FD>' is not assignable to type 'filterEffect<S, FD>'.
- packages/effect/src/Schema.ts#L3764 in packages/effect/tsconfig.src.json

packages/effect/dtslint/tsconfig.json

[NEW] error TS2322: Type 'transformOrFail<S, SchemaClass<any, any, never> | S, FD>' is not assignable to type 'filterEffect<S, FD>'.
- packages/effect/src/Schema.ts#L3764 in packages/effect/tsconfig.src.json

webpack

tsconfig.types.test.json

[NEW] error TS2345: Argument of type 'HookMap<SyncBailHook<T, R, UnsetAdditionalOptions>>' is not assignable to parameter of type 'HookMap<SyncBailHook<T | [...AsArray<T>], R, UnsetAdditionalOptions>>'.

tsconfig.types.json

[NEW] error TS2345: Argument of type 'HookMap<SyncBailHook<T, R, UnsetAdditionalOptions>>' is not assignable to parameter of type 'HookMap<SyncBailHook<T | [...AsArray<T>], R, UnsetAdditionalOptions>>'.

tsconfig.json

[NEW] error TS2345: Argument of type 'HookMap<SyncBailHook<T, R, UnsetAdditionalOptions>>' is not assignable to parameter of type 'HookMap<SyncBailHook<T | [...AsArray<T>], R, UnsetAdditionalOptions>>'.

typescript-bot · 2025-07-21T19:44:24Z

@RyanCavanaugh
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	_62,370	_62,370	_~	_~	_~	_{p=1.000 n=6}
_Types	_50,386	_50,386	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{193,573k (± 0.76%)}	_{194,753k (± 1.04%)}	_~	_192,901k	_196,743k	_{p=0.575 n=6}
_{Parse Time}	_{1.30s (± 0.64%)}	_{1.30s (± 0.79%)}	_~	_1.29s	_1.31s	_{p=0.923 n=6}
_{Bind Time}	_0.73s	_0.73s	_~	_~	_~	_{p=1.000 n=6}
_{Check Time}	_{9.75s (± 0.40%)}	_{9.74s (± 0.22%)}	_~	_9.71s	_9.77s	_{p=0.260 n=6}
_{Emit Time}	_{2.74s (± 0.78%)}	_{2.75s (± 0.69%)}	_~	_2.73s	_2.78s	_{p=0.511 n=6}
_{Total Time}	_{14.52s (± 0.30%)}	_{14.52s (± 0.13%)}	_~	_14.50s	_14.54s	_{p=0.513 n=6}
_{angular-1 - node (v18.15.0, x64)}
_Errors	₅₆	₅₆	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_948,914	_948,914	_~	_~	_~	_{p=1.000 n=6}
_Types	_410,884	_410,884	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{1,226,389k (± 0.00%)}	_{1,226,395k (± 0.01%)}	_~	_1,226,322k	_1,226,495k	_{p=0.936 n=6}
_{Parse Time}	_{6.53s (± 1.02%)}	_{6.52s (± 0.85%)}	_~	_6.46s	_6.62s	_{p=1.000 n=6}
_{Bind Time}	_{1.87s (± 0.44%)}	_1.87s	_~	_~	_~	_{p=0.290 n=6}
_{Check Time}	_{32.00s (± 0.27%)}	_{31.97s (± 0.31%)}	_~	_31.88s	_32.10s	_{p=0.748 n=6}
_{Emit Time}	_{14.86s (± 0.97%)}	_{14.85s (± 0.59%)}	_~	_14.74s	_14.94s	_{p=0.688 n=6}
_{Total Time}	_{55.26s (± 0.30%)}	_{55.21s (± 0.22%)}	_~	_55.02s	_55.36s	_{p=0.423 n=6}
_{mui-docs - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,542,899	_2,542,993	_{+94 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_900,428	_900,433	_{+5 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,829,362k (± 0.00%)}	_{2,829,402k (± 0.01%)}	_~	_2,829,202k	_2,829,600k	_{p=0.688 n=6}
_{Parse Time}	_{8.76s (± 0.29%)}	_{8.75s (± 0.22%)}	_~	_8.72s	_8.77s	_{p=0.683 n=6}
_{Bind Time}	_{2.26s (± 0.23%)}	_{2.24s (± 0.36%)}	_{-0.01s (- 0.59%)}	_2.23s	_2.25s	_{p=0.014 n=6}
_{Check Time}	_{85.74s (± 0.31%)}	_{85.56s (± 0.49%)}	_~	_84.98s	_86.20s	_{p=0.378 n=6}
_{Emit Time}	_{0.59s (±119.68%)}	_{1.01s (±95.34%)}	_~	_0.30s	_2.24s	_{p=0.184 n=6}
_{Total Time}	_{97.35s (± 0.86%)}	_{97.56s (± 0.75%)}	_~	_96.64s	_98.57s	_{p=0.575 n=6}
_{self-build-src - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,227,048	_1,227,076	_{+28 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_267,470	_267,475	_{+5 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,363,435k (± 0.01%)}	_{2,363,612k (± 0.02%)}	_~	_2,363,060k	_2,364,027k	_{p=0.378 n=6}
_{Parse Time}	_{5.21s (± 1.05%)}	_{5.21s (± 1.13%)}	_~	_5.14s	_5.30s	_{p=0.872 n=6}
_{Bind Time}	_{1.80s (± 0.84%)}	_{1.79s (± 1.62%)}	_~	_1.76s	_1.83s	_{p=0.684 n=6}
_{Check Time}	_{35.34s (± 0.46%)}	_{35.43s (± 0.45%)}	_~	_35.23s	_35.68s	_{p=0.298 n=6}
_{Emit Time}	_{2.98s (± 1.32%)}	_{2.97s (± 0.88%)}	_~	_2.93s	_3.00s	_{p=0.630 n=6}
_{Total Time}	_{45.34s (± 0.37%)}	_{45.41s (± 0.40%)}	_~	_45.21s	_45.71s	_{p=0.575 n=6}
_{self-build-src-public-api - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,227,048	_1,227,076	_{+28 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_267,470	_267,475	_{+5 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{3,039,849k (± 9.77%)}	_{3,161,978k (± 0.02%)}	_~	_3,161,210k	_3,162,728k	_{p=0.093 n=6}
_{Parse Time}	_{8.50s (± 1.20%)}	_{8.55s (± 0.46%)}	_~	_8.51s	_8.61s	_{p=0.575 n=6}
_{Bind Time}	_{2.66s (± 1.80%)}	_{2.64s (± 0.95%)}	_~	_2.61s	_2.67s	_{p=0.689 n=6}
_{Check Time}	_{53.22s (± 0.48%)}	_{53.26s (± 0.23%)}	_~	_53.10s	_53.45s	_{p=0.936 n=6}
_{Emit Time}	_{4.46s (± 2.87%)}	_{4.34s (± 2.32%)}	_~	_4.21s	_4.45s	_{p=0.090 n=6}
_{Total Time}	_{68.83s (± 0.48%)}	_{68.79s (± 0.21%)}	_~	_68.66s	_69.05s	_{p=0.936 n=6}
_{self-compiler - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_262,548	_262,554	_{+6 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_107,156	_107,161	_{+5 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{441,929k (± 0.01%)}	_{441,933k (± 0.01%)}	_~	_441,855k	_442,020k	_{p=0.936 n=6}
_{Parse Time}	_{3.56s (± 0.75%)}	_{3.52s (± 0.61%)}	_{-0.04s (- 1.22%)}	_3.49s	_3.55s	_{p=0.024 n=6}
_{Bind Time}	_{1.32s (± 1.07%)}	_{1.32s (± 0.89%)}	_~	_1.30s	_1.33s	_{p=0.934 n=6}
_{Check Time}	_{18.96s (± 0.39%)}	_{18.94s (± 0.46%)}	_~	_18.86s	_19.10s	_{p=0.328 n=6}
_{Emit Time}	_{1.52s (± 0.68%)}	_{1.53s (± 1.36%)}	_~	_1.49s	_1.55s	_{p=0.677 n=6}
_{Total Time}	_{25.36s (± 0.33%)}	_{25.30s (± 0.30%)}	_~	_25.25s	_25.44s	_{p=0.170 n=6}
_{ts-pre-modules - node (v18.15.0, x64)}
_Errors	₇₁	₇₁	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_225,367	_225,367	_~	_~	_~	_{p=1.000 n=6}
_Types	_94,290	_94,290	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{371,155k (± 0.03%)}	_{371,137k (± 0.02%)}	_~	_371,062k	_371,229k	_{p=1.000 n=6}
_{Parse Time}	_{2.87s (± 0.72%)}	_{2.89s (± 0.99%)}	_~	_2.84s	_2.92s	_{p=0.257 n=6}
_{Bind Time}	_{1.59s (± 1.45%)}	_{1.61s (± 0.94%)}	_~	_1.59s	_1.63s	_{p=0.243 n=6}
_{Check Time}	_{16.45s (± 0.27%)}	_{16.45s (± 0.38%)}	_~	_16.36s	_16.51s	_{p=0.936 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{20.92s (± 0.30%)}	_{20.95s (± 0.36%)}	_~	_20.85s	_21.02s	_{p=0.423 n=6}
_{vscode - node (v18.15.0, x64)}
_Errors	₁	₁	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_3,524,145	_3,524,145	_~	_~	_~	_{p=1.000 n=6}
_Types	_1,189,792	_1,189,792	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{3,573,696k (± 0.00%)}	_{3,573,744k (± 0.00%)}	_~	_3,573,612k	_3,574,010k	_{p=0.936 n=6}
_{Parse Time}	_{15.09s (± 0.25%)}	_{15.31s (± 3.24%)}	_~	_15.03s	_16.31s	_{p=0.518 n=6}
_{Bind Time}	_{4.89s (± 0.56%)}	_{4.93s (± 0.70%)}	_~	_4.89s	_4.97s	_{p=0.063 n=6}
_{Check Time}	_{101.49s (± 2.87%)}	_{99.85s (± 0.91%)}	_~	_99.03s	_101.54s	_{p=0.298 n=6}
_{Emit Time}	_{31.45s (± 6.16%)}	_{30.51s (± 0.72%)}	_~	_30.17s	_30.82s	_{p=0.575 n=6}
_{Total Time}	_{152.91s (± 1.99%)}	_{150.60s (± 0.79%)}	_~	_149.19s	_152.16s	_{p=0.173 n=6}
_{webpack - node (v18.15.0, x64)}
_Errors	₂	₇	_{🔻+5 (+250.00%)}	_~	_~	_{p=0.001 n=6}
_Symbols	_320,541	_330,861	_{+10,320 (+ 3.22%)}	_~	_~	_{p=0.001 n=6}
_Types	_140,016	_146,362	_{🔻+6,346 (+ 4.53%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{476,527k (± 0.04%)}	_{483,704k (± 0.02%)}	_{+7,176k (+ 1.51%)}	_483,576k	_483,847k	_{p=0.005 n=6}
_{Parse Time}	_{4.31s (± 0.54%)}	_{4.30s (± 0.74%)}	_~	_4.25s	_4.35s	_{p=0.935 n=6}
_{Bind Time}	_{1.80s (± 0.97%)}	_{1.79s (± 1.29%)}	_~	_1.75s	_1.82s	_{p=0.567 n=6}
_{Check Time}	_{20.60s (± 0.40%)}	_{20.91s (± 0.45%)}	_{+0.31s (+ 1.49%)}	_20.83s	_21.07s	_{p=0.005 n=6}
_{Emit Time}	_0.00s	_{0.00s (±154.76%)}	_~	_0.00s	_0.01s	_{p=0.174 n=6}
_{Total Time}	_{26.71s (± 0.33%)}	_{27.00s (± 0.49%)}	_{+0.29s (+ 1.08%)}	_26.85s	_27.21s	_{p=0.006 n=6}
_{xstate-main - node (v18.15.0, x64)}
_Errors	₃₀	₃₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_662,663	_662,663	_~	_~	_~	_{p=1.000 n=6}
_Types	_197,635	_197,637	_{+2 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{569,834k (± 0.02%)}	_{569,778k (± 0.02%)}	_~	_569,601k	_569,883k	_{p=0.810 n=6}
_{Parse Time}	_{4.27s (± 0.53%)}	_{4.25s (± 0.51%)}	_~	_4.22s	_4.28s	_{p=0.366 n=6}
_{Bind Time}	_{1.32s (± 0.88%)}	_{1.33s (± 0.88%)}	_~	_1.31s	_1.34s	_{p=0.357 n=6}
_{Check Time}	_{19.96s (± 1.38%)}	_{20.08s (± 1.58%)}	_~	_19.79s	_20.53s	_{p=0.336 n=6}
_{Emit Time}	_{0.00s (±244.70%)}	_0.00s	_~	_~	_~	_{p=0.405 n=6}
_{Total Time}	_{25.55s (± 1.10%)}	_{25.66s (± 1.32%)}	_~	_25.33s	_26.12s	_{p=0.689 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 · 2025-07-21T20:45:33Z

@RyanCavanaugh Here are the results of running the top 400 repos with tsc comparing main and refs/pull/62093/merge:

Something interesting changed - please have a look.

Details

TanStack/query

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

packages/vue-query/tsconfig.prod.json

error TS2344: Type '{ wow: boolean; }' does not satisfy the constraint '"Expected: ..., Actual: function"'.
error TS2344: Type '{ wow: boolean; } | undefined' does not satisfy the constraint '"Expected: ..., Actual: function" | "Expected: undefined, Actual: function"'.
- packages/vue-query/src/__tests__/queryOptions.test-d.ts#L180 in packages/vue-query/tsconfig.prod.json
- packages/vue-query/src/__tests__/useQuery.test-d.ts#L106 in packages/vue-query/tsconfig.prod.json

jakebailey · 2025-08-14T20:05:44Z

@typescript-bot pack this

typescript-bot · 2025-08-14T20:05:50Z

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

Command	Status	Results
`pack this`	✅ Started	✅ Results

typescript-bot · 2025-08-14T20:10:41Z

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/165893/artifacts?artifactName=tgz&fileId=96814B8D1AB03813E1E3411F26BA36E8666C8DE5DD9C65C3DB7356516BE2045002&fileName=/typescript-6.0.0-insiders.20250814.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/[email protected]".;

…-parameters

Andarist · 2025-08-19T09:44:12Z

@jakebailey could you rerun tests and build a playground for this? :)

jakebailey · 2025-08-19T15:55:14Z

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

typescript-bot · 2025-08-19T15:55:20Z

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 · 2025-08-19T15:59:42Z

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/165913/artifacts?artifactName=tgz&fileId=CEA60AD23CEDEF8C53BBD234DF84C69F7D4FE1DD54417AA138F133466C4B7C3502&fileName=/typescript-6.0.0-insiders.20250819.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/[email protected]".;

typescript-bot · 2025-08-19T16:18:35Z

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

Everything looks the same!

You can check the log here.

typescript-bot · 2025-08-19T16:21:10Z

@jakebailey Here are the results of running the user tests with tsc comparing main and refs/pull/62093/merge:

There were infrastructure failures potentially unrelated to your change:

1 instance of "Git clone failed"

Otherwise...

Everything looks good!

typescript-bot · 2025-08-19T16:52:23Z

@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	_62,370	_62,370	_~	_~	_~	_{p=1.000 n=6}
_Types	_50,386	_50,386	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{194,803k (± 0.98%)}	_{194,721k (± 1.02%)}	_~	_192,871k	_196,557k	_{p=0.810 n=6}
_{Parse Time}	_{1.30s (± 0.84%)}	_1.31s	_~	_~	_~	_{p=0.071 n=6}
_{Bind Time}	_0.73s	_0.73s	_~	_~	_~	_{p=1.000 n=6}
_{Check Time}	_{9.75s (± 0.39%)}	_{9.73s (± 0.35%)}	_~	_9.69s	_9.77s	_{p=0.418 n=6}
_{Emit Time}	_{2.74s (± 0.46%)}	_{2.73s (± 0.82%)}	_~	_2.71s	_2.76s	_{p=0.511 n=6}
_{Total Time}	_{14.52s (± 0.23%)}	_{14.50s (± 0.25%)}	_~	_14.45s	_14.53s	_{p=0.808 n=6}
_{angular-1 - node (v18.15.0, x64)}
_Errors	₅₆	₅₆	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_948,914	_948,914	_~	_~	_~	_{p=1.000 n=6}
_Types	_410,884	_410,884	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{1,226,424k (± 0.00%)}	_{1,226,399k (± 0.00%)}	_~	_1,226,369k	_1,226,448k	_{p=0.199 n=6}
_{Parse Time}	_{6.48s (± 0.51%)}	_{6.48s (± 0.24%)}	_~	_6.46s	_6.50s	_{p=0.739 n=6}
_{Bind Time}	_{1.87s (± 0.28%)}	_{1.87s (± 0.22%)}	_~	_1.86s	_1.87s	_{p=0.114 n=6}
_{Check Time}	_{32.08s (± 0.25%)}	_{31.97s (± 0.48%)}	_~	_31.79s	_32.16s	_{p=0.297 n=6}
_{Emit Time}	_{14.83s (± 0.30%)}	_{14.76s (± 0.83%)}	_~	_14.55s	_14.87s	_{p=0.378 n=6}
_{Total Time}	_{55.27s (± 0.20%)}	_{55.08s (± 0.42%)}	_~	_54.69s	_55.30s	_{p=0.199 n=6}
_{mui-docs - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,545,274	_2,545,274	_~	_~	_~	_{p=1.000 n=6}
_Types	_902,468	_902,469	_{+1 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,829,310k (± 0.00%)}	_{2,829,124k (± 0.01%)}	_{-186k (- 0.01%)}	_2,828,891k	_2,829,243k	_{p=0.005 n=6}
_{Parse Time}	_{8.73s (± 0.32%)}	_{8.72s (± 0.20%)}	_~	_8.70s	_8.75s	_{p=0.677 n=6}
_{Bind Time}	_{2.23s (± 0.87%)}	_{2.23s (± 0.37%)}	_~	_2.21s	_2.23s	_{p=1.000 n=6}
_{Check Time}	_{86.06s (± 0.38%)}	_{85.93s (± 0.29%)}	_~	_85.64s	_86.31s	_{p=0.575 n=6}
_{Emit Time}	_{0.30s (± 1.35%)}	_{1.00s (±107.80%)}	_~	_0.30s	_2.41s	_{p=0.214 n=6}
_{Total Time}	_{97.32s (± 0.32%)}	_{97.88s (± 1.19%)}	_~	_96.91s	_99.44s	_{p=1.000 n=6}
_{self-build-src - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,236,880	_1,236,908	_{+28 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_259,623	_259,628	_{+5 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,507,480k (±11.82%)}	_{2,629,188k (±14.26%)}	_~	_2,386,548k	_3,113,786k	_{p=0.093 n=6}
_{Parse Time}	_{5.19s (± 1.14%)}	_{5.25s (± 1.46%)}	_~	_5.16s	_5.35s	_{p=0.173 n=6}
_{Bind Time}	_{1.80s (± 1.28%)}	_{1.79s (± 1.04%)}	_~	_1.77s	_1.82s	_{p=0.292 n=6}
_{Check Time}	_{35.10s (± 0.38%)}	_{35.23s (± 0.51%)}	_~	_35.10s	_35.49s	_{p=0.199 n=6}
_{Emit Time}	_{2.99s (± 0.72%)}	_{3.00s (± 0.53%)}	_~	_2.99s	_3.03s	_{p=0.422 n=6}
_{Total Time}	_{45.10s (± 0.34%)}	_{45.27s (± 0.52%)}	_~	_45.09s	_45.59s	_{p=0.128 n=6}
_{self-build-src-public-api - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,236,880	_1,236,908	_{+28 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_259,623	_259,628	_{+5 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{3,060,308k (± 9.66%)}	_{2,697,994k (±13.84%)}	_~	_2,456,531k	_3,181,656k	_{p=0.173 n=6}
_{Parse Time}	_{6.92s (± 0.79%)}	_{6.80s (± 1.77%)}	_~	_6.67s	_7.01s	_{p=0.054 n=6}
_{Bind Time}	_{2.19s (± 2.10%)}	_{2.22s (± 1.20%)}	_~	_2.17s	_2.24s	_{p=0.229 n=6}
_{Check Time}	_{42.63s (± 0.35%)}	_{42.41s (± 0.46%)}	_~	_42.19s	_42.73s	_{p=0.066 n=6}
_{Emit Time}	_{3.55s (± 1.22%)}	_{3.53s (± 2.29%)}	_~	_3.43s	_3.62s	_{p=0.810 n=6}
_{Total Time}	_{55.27s (± 0.36%)}	_{54.96s (± 0.49%)}	_~	_54.72s	_55.39s	_{p=0.066 n=6}
_{self-compiler - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_262,407	_262,413	_{+6 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_103,907	_103,912	_{+5 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{441,665k (± 0.02%)}	_{441,698k (± 0.01%)}	_~	_441,622k	_441,780k	_{p=0.470 n=6}
_{Parse Time}	_{4.40s (± 0.75%)}	_{4.40s (± 0.56%)}	_~	_4.37s	_4.43s	_{p=0.872 n=6}
_{Bind Time}	_{1.64s (± 1.59%)}	_{1.63s (± 1.44%)}	_~	_1.60s	_1.66s	_{p=0.331 n=6}
_{Check Time}	_{23.46s (± 0.21%)}	_{23.56s (± 0.59%)}	_~	_23.35s	_23.72s	_{p=0.229 n=6}
_{Emit Time}	_{1.91s (± 1.08%)}	_{1.91s (± 1.78%)}	_~	_1.87s	_1.95s	_{p=0.871 n=6}
_{Total Time}	_{31.41s (± 0.21%)}	_{31.48s (± 0.42%)}	_~	_31.28s	_31.61s	_{p=0.297 n=6}
_{ts-pre-modules - node (v18.15.0, x64)}
_Errors	₇₁	₇₁	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_225,367	_225,367	_~	_~	_~	_{p=1.000 n=6}
_Types	_94,290	_94,290	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{371,186k (± 0.04%)}	_{371,179k (± 0.03%)}	_~	_371,047k	_371,358k	_{p=0.810 n=6}
_{Parse Time}	_{3.56s (± 1.71%)}	_{3.61s (± 1.04%)}	_~	_3.55s	_3.65s	_{p=0.199 n=6}
_{Bind Time}	_{1.97s (± 1.17%)}	_{1.95s (± 0.75%)}	_~	_1.93s	_1.97s	_{p=0.073 n=6}
_{Check Time}	_{20.40s (± 0.42%)}	_{20.37s (± 0.29%)}	_~	_20.31s	_20.47s	_{p=0.518 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{25.94s (± 0.38%)}	_{25.93s (± 0.24%)}	_~	_25.87s	_26.03s	_{p=0.688 n=6}
_{vscode - node (v18.15.0, x64)}
_Errors	₁	₁	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_3,855,997	_3,855,997	_~	_~	_~	_{p=1.000 n=6}
_Types	_1,215,302	_1,215,302	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{3,686,091k (± 0.01%)}	_{3,686,183k (± 0.01%)}	_~	_3,685,774k	_3,686,340k	_{p=0.471 n=6}
_{Parse Time}	_{19.06s (± 3.02%)}	_{18.86s (± 0.61%)}	_~	_18.70s	_18.99s	_{p=1.000 n=6}
_{Bind Time}	_{6.48s (±13.67%)}	_{6.09s (± 2.02%)}	_~	_6.00s	_6.34s	_{p=0.375 n=6}
_{Check Time}	_{126.17s (± 5.72%)}	_{122.37s (± 1.32%)}	_~	_120.50s	_125.32s	_{p=0.471 n=6}
_{Emit Time}	_{41.39s (±11.49%)}	_{43.21s (±26.18%)}	_~	_36.77s	_65.26s	_{p=0.810 n=6}
_{Total Time}	_{193.09s (± 5.04%)}	_{190.54s (± 5.42%)}	_~	_184.18s	_210.75s	_{p=0.471 n=6}
_{webpack - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_320,599	_320,599	_~	_~	_~	_{p=1.000 n=6}
_Types	_139,279	_139,279	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{477,261k (± 0.02%)}	_{477,306k (± 0.03%)}	_~	_477,151k	_477,466k	_{p=0.689 n=6}
_{Parse Time}	_{4.30s (± 0.39%)}	_{4.31s (± 0.82%)}	_~	_4.26s	_4.36s	_{p=0.570 n=6}
_{Bind Time}	_{1.86s (± 0.73%)}	_{1.83s (± 1.00%)}	_{-0.03s (- 1.70%)}	_1.80s	_1.85s	_{p=0.007 n=6}
_{Check Time}	_{21.12s (± 0.21%)}	_{21.06s (± 0.29%)}	_~	_21.00s	_21.17s	_{p=0.077 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{27.28s (± 0.13%)}	_{27.20s (± 0.30%)}	_{-0.08s (- 0.29%)}	_27.06s	_27.30s	_{p=0.037 n=6}
_{xstate-main - node (v18.15.0, x64)}
_Errors	₃₀	₃₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_666,075	_666,075	_~	_~	_~	_{p=1.000 n=6}
_Types	_199,738	_199,740	_{+2 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{572,611k (± 0.03%)}	_{572,550k (± 0.02%)}	_~	_572,398k	_572,671k	_{p=0.298 n=6}
_{Parse Time}	_{4.28s (± 0.59%)}	_{4.27s (± 0.87%)}	_~	_4.22s	_4.32s	_{p=0.871 n=6}
_{Bind Time}	_{1.33s (± 1.02%)}	_{1.33s (± 1.02%)}	_~	_1.32s	_1.36s	_{p=0.669 n=6}
_{Check Time}	_{20.28s (± 2.01%)}	_{20.45s (± 2.06%)}	_~	_20.00s	_20.86s	_{p=0.332 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{25.90s (± 1.50%)}	_{26.05s (± 1.60%)}	_~	_25.64s	_26.47s	_{p=0.261 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 · 2025-08-19T17:38:35Z

@jakebailey Here are the results of running the top 400 repos with tsc comparing main and refs/pull/62093/merge:

Everything looks good!

Andarist · 2025-08-20T07:11:05Z

I slept on it and figured out a slightly better adjustment to the algorithm than the last fix - the new version has to be tested now.

jakebailey · 2025-08-20T18:43:53Z

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

typescript-bot · 2025-08-20T18:43:59Z

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 · 2025-08-20T18:48:45Z

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/165924/artifacts?artifactName=tgz&fileId=504EAD6FF94ECBC6F82B377C07B66CEC1F5B3D56D020FC5E1F9B1835D5101D0C02&fileName=/typescript-6.0.0-insiders.20250820.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/[email protected]".;

typescript-bot · 2025-08-20T19:08:05Z

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

Everything looks the same!

You can check the log here.

typescript-bot · 2025-08-20T19:09:19Z

@jakebailey Here are the results of running the user tests with tsc comparing main and refs/pull/62093/merge:

There were infrastructure failures potentially unrelated to your change:

1 instance of "Git clone failed"

Otherwise...

Everything looks good!

typescript-bot · 2025-08-20T19:30:56Z

@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	_62,370	_62,370	_~	_~	_~	_{p=1.000 n=6}
_Types	_50,386	_50,386	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{193,516k (± 0.75%)}	_{193,521k (± 0.76%)}	_~	_192,911k	_196,521k	_{p=0.936 n=6}
_{Parse Time}	_{1.31s (± 0.64%)}	_{1.31s (± 0.31%)}	_~	_1.31s	_1.32s	_{p=0.115 n=6}
_{Bind Time}	_0.73s	_0.73s	_~	_~	_~	_{p=1.000 n=6}
_{Check Time}	_{9.73s (± 0.17%)}	_{9.75s (± 0.21%)}	_~	_9.71s	_9.77s	_{p=0.194 n=6}
_{Emit Time}	_{2.75s (± 0.71%)}	_{2.76s (± 0.44%)}	_~	_2.74s	_2.77s	_{p=0.372 n=6}
_{Total Time}	_{14.51s (± 0.18%)}	_{14.54s (± 0.17%)}	_~	_14.50s	_14.57s	_{p=0.124 n=6}
_{angular-1 - node (v18.15.0, x64)}
_Errors	₅₆	₅₆	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_948,914	_948,914	_~	_~	_~	_{p=1.000 n=6}
_Types	_410,884	_410,884	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{1,226,389k (± 0.00%)}	_{1,226,384k (± 0.00%)}	_~	_1,226,326k	_1,226,441k	_{p=1.000 n=6}
_{Parse Time}	_{6.52s (± 1.05%)}	_{6.50s (± 0.48%)}	_~	_6.46s	_6.54s	_{p=0.746 n=6}
_{Bind Time}	_{1.87s (± 0.34%)}	_{1.88s (± 0.29%)}	_~	_1.87s	_1.88s	_{p=0.201 n=6}
_{Check Time}	_{32.10s (± 0.26%)}	_{32.00s (± 0.20%)}	_{-0.10s (- 0.31%)}	_31.90s	_32.08s	_{p=0.045 n=6}
_{Emit Time}	_{14.77s (± 0.73%)}	_{14.83s (± 0.45%)}	_~	_14.74s	_14.91s	_{p=0.377 n=6}
_{Total Time}	_{55.25s (± 0.18%)}	_{55.21s (± 0.19%)}	_~	_55.10s	_55.39s	_{p=0.689 n=6}
_{mui-docs - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,545,275	_2,545,369	_{+94 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_902,468	_902,473	_{+5 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,829,169k (± 0.01%)}	_{2,829,422k (± 0.00%)}	_{+254k (+ 0.01%)}	_2,829,373k	_2,829,491k	_{p=0.005 n=6}
_{Parse Time}	_{8.73s (± 0.24%)}	_{8.73s (± 0.28%)}	_~	_8.69s	_8.75s	_{p=1.000 n=6}
_{Bind Time}	_{2.23s (± 0.28%)}	_{2.23s (± 0.49%)}	_~	_2.22s	_2.25s	_{p=0.787 n=6}
_{Check Time}	_{85.82s (± 0.26%)}	_{86.08s (± 0.38%)}	_~	_85.44s	_86.39s	_{p=0.173 n=6}
_{Emit Time}	_{0.66s (±112.27%)}	_{0.30s (± 1.79%)}	_~	_0.30s	_0.31s	_{p=0.663 n=6}
_{Total Time}	_{97.44s (± 0.89%)}	_{97.34s (± 0.36%)}	_~	_96.67s	_97.68s	_{p=0.810 n=6}
_{self-build-src - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,236,880	_1,236,908	_{+28 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_259,623	_259,628	_{+5 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{3,116,397k (± 0.03%)}	_{2,995,822k (± 9.88%)}	_~	_2,390,871k	_3,117,500k	_{p=0.810 n=6}
_{Parse Time}	_{8.33s (± 0.53%)}	_{8.28s (± 1.65%)}	_~	_8.03s	_8.41s	_{p=0.936 n=6}
_{Bind Time}	_{2.64s (± 0.68%)}	_{2.65s (± 1.71%)}	_~	_2.61s	_2.74s	_{p=0.873 n=6}
_{Check Time}	_{52.53s (± 0.54%)}	_{52.62s (± 0.46%)}	_~	_52.14s	_52.80s	_{p=0.521 n=6}
_{Emit Time}	_{4.37s (± 1.32%)}	_{4.36s (± 3.14%)}	_~	_4.22s	_4.60s	_{p=0.575 n=6}
_{Total Time}	_{67.86s (± 0.40%)}	_{67.91s (± 0.61%)}	_~	_67.10s	_68.27s	_{p=0.575 n=6}
_{self-build-src-public-api - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,236,880	_1,236,908	_{+28 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_259,623	_259,628	_{+5 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{3,180,440k (± 0.02%)}	_{3,060,187k (± 9.65%)}	_~	_2,456,470k	_3,181,702k	_{p=0.575 n=6}
_{Parse Time}	_{6.92s (± 0.30%)}	_{6.88s (± 1.33%)}	_~	_6.70s	_6.94s	_{p=0.629 n=6}
_{Bind Time}	_{2.17s (± 0.54%)}	_{2.19s (± 1.46%)}	_~	_2.16s	_2.23s	_{p=0.222 n=6}
_{Check Time}	_{42.48s (± 0.20%)}	_{42.66s (± 0.41%)}	_~	_42.43s	_42.84s	_{p=0.093 n=6}
_{Emit Time}	_{3.52s (± 1.92%)}	_{3.55s (± 1.56%)}	_~	_3.47s	_3.61s	_{p=0.471 n=6}
_{Total Time}	_{55.10s (± 0.13%)}	_{55.29s (± 0.51%)}	_~	_54.83s	_55.59s	_{p=0.093 n=6}
_{self-compiler - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_262,407	_262,413	_{+6 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_103,907	_103,912	_{+5 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{441,570k (± 0.01%)}	_{441,647k (± 0.01%)}	_{+76k (+ 0.02%)}	_441,572k	_441,751k	_{p=0.045 n=6}
_{Parse Time}	_{2.92s (± 0.47%)}	_{2.93s (± 0.55%)}	_~	_2.90s	_2.94s	_{p=0.140 n=6}
_{Bind Time}	_{1.11s (± 1.35%)}	_{1.12s (± 1.08%)}	_~	_1.10s	_1.13s	_{p=0.256 n=6}
_{Check Time}	_{15.82s (± 0.39%)}	_{15.88s (± 0.29%)}	_~	_15.82s	_15.94s	_{p=0.146 n=6}
_{Emit Time}	_{1.32s (± 1.05%)}	_{1.31s (± 1.12%)}	_~	_1.29s	_1.32s	_{p=0.460 n=6}
_{Total Time}	_{21.16s (± 0.29%)}	_{21.23s (± 0.25%)}	_~	_21.17s	_21.32s	_{p=0.106 n=6}
_{ts-pre-modules - node (v18.15.0, x64)}
_Errors	₇₁	₇₁	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_225,367	_225,367	_~	_~	_~	_{p=1.000 n=6}
_Types	_94,290	_94,290	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{371,163k (± 0.06%)}	_{371,144k (± 0.02%)}	_~	_371,073k	_371,268k	_{p=0.128 n=6}
_{Parse Time}	_{3.58s (± 1.68%)}	_{3.60s (± 0.67%)}	_~	_3.56s	_3.63s	_{p=0.806 n=6}
_{Bind Time}	_{1.98s (± 1.04%)}	_{1.97s (± 0.50%)}	_~	_1.95s	_1.98s	_{p=0.559 n=6}
_{Check Time}	_{20.37s (± 0.31%)}	_{20.39s (± 0.37%)}	_~	_20.31s	_20.48s	_{p=0.573 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{25.92s (± 0.33%)}	_{25.96s (± 0.28%)}	_~	_25.85s	_26.03s	_{p=0.469 n=6}
_{vscode - node (v18.15.0, x64)}
_Errors	₁	₁	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_3,858,457	_3,858,457	_~	_~	_~	_{p=1.000 n=6}
_Types	_1,216,169	_1,216,169	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{3,688,341k (± 0.00%)}	_{3,688,331k (± 0.00%)}	_~	_3,688,141k	_3,688,437k	_{p=0.689 n=6}
_{Parse Time}	_{15.25s (± 0.89%)}	_{15.26s (± 0.62%)}	_~	_15.15s	_15.40s	_{p=0.745 n=6}
_{Bind Time}	_{4.90s (± 0.28%)}	_{4.89s (± 0.65%)}	_~	_4.84s	_4.93s	_{p=1.000 n=6}
_{Check Time}	_{101.50s (± 2.46%)}	_{101.60s (± 2.07%)}	_~	_99.70s	_105.56s	_{p=0.575 n=6}
_{Emit Time}	_{31.43s (± 5.82%)}	_{34.48s (±19.90%)}	_~	_30.37s	_47.36s	_{p=0.873 n=6}
_{Total Time}	_{153.08s (± 2.19%)}	_{156.22s (± 4.69%)}	_~	_150.25s	_169.31s	_{p=0.261 n=6}
_{webpack - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_320,926	_320,954	_{+28 (+ 0.01%)}	_~	_~	_{p=0.001 n=6}
_Types	_139,510	_139,529	_{+19 (+ 0.01%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{477,765k (± 0.02%)}	_{477,903k (± 0.02%)}	_{+139k (+ 0.03%)}	_477,740k	_478,024k	_{p=0.045 n=6}
_{Parse Time}	_{4.36s (± 0.65%)}	_{4.35s (± 0.85%)}	_~	_4.29s	_4.39s	_{p=1.000 n=6}
_{Bind Time}	_{1.86s (± 1.21%)}	_{1.84s (± 0.64%)}	_~	_1.82s	_1.85s	_{p=0.115 n=6}
_{Check Time}	_{21.13s (± 0.45%)}	_{21.19s (± 0.37%)}	_~	_21.07s	_21.26s	_{p=0.336 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{27.35s (± 0.29%)}	_{27.38s (± 0.27%)}	_~	_27.30s	_27.47s	_{p=0.335 n=6}
_{xstate-main - node (v18.15.0, x64)}
_Errors	₃₀	₃₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_666,075	_666,075	_~	_~	_~	_{p=1.000 n=6}
_Types	_199,738	_199,740	_{+2 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{572,436k (± 0.03%)}	_{572,623k (± 0.03%)}	_~	_572,342k	_572,776k	_{p=0.149 n=6}
_{Parse Time}	_{5.30s (± 0.47%)}	_{5.33s (± 0.46%)}	_~	_5.30s	_5.37s	_{p=0.052 n=6}
_{Bind Time}	_{1.65s (± 0.83%)}	_{1.64s (± 0.51%)}	_~	_1.64s	_1.66s	_{p=0.262 n=6}
_{Check Time}	_{25.48s (± 1.66%)}	_{24.98s (± 1.14%)}	_~	_24.76s	_25.54s	_{p=0.065 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{32.43s (± 1.28%)}	_{31.96s (± 0.98%)}	_~	_31.74s	_32.58s	_{p=0.092 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 · 2025-08-20T20:26:05Z

@jakebailey Here are the results of running the top 400 repos with tsc comparing main and refs/pull/62093/merge:

Everything looks good!

Andarist added 3 commits July 20, 2025 08:51

Combine inferences from distributive conditional types

09e5824

keep those inferences when "external" candidates are found

cf7ea8a

fixup whitespace

ed80c21

Copilot AI review requested due to automatic review settings July 20, 2025 10:52

github-project-automation bot added this to PR Backlog Jul 20, 2025

github-project-automation bot moved this to Not started in PR Backlog Jul 20, 2025

typescript-bot added the For Backlog Bug PRs that fix a backlog bug label Jul 20, 2025

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Andarist commented Jul 20, 2025

View reviewed changes

add extra test case

3a10dd2

Andarist added 2 commits August 19, 2025 11:43

don't infer from multiple distributive conditional types for now

c67b5de

Merge remote-tracking branch 'origin/main' into fix/generic-functions…

a237744

…-parameters

improve the fix

80ad253

Combine inferences from distributive conditional types #62093

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Combine inferences from distributive conditional types #62093

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