Only resolve source return type when actually needed during inference #58650

ahejlsberg · 2024-05-24T17:25:13Z

Fixes #58616. Also fixes an unnecessary circularity in one of our existing tests.

# Conflicts: # tests/baselines/reference/circularReferenceInReturnType.types

ahejlsberg · 2024-05-24T17:37:07Z

typescript-bot · 2024-05-24T17:37:10Z

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 · 2024-05-24T17:56:42Z

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

Everything looks the same!

You can check the log here.

typescript-bot · 2024-05-24T18:03:34Z

@ahejlsberg Here are the results of running the user tests comparing main and refs/pull/58650/merge:

Something interesting changed - please have a look.

Details

webpack

tsconfig.types.json

[NEW] error TS7024: Function implicitly has return type 'any' because it does not have a return type annotation and is referenced directly or indirectly in one of its return expressions.
- lib/dependencies/JsonExportsDependency.js#L25

typescript-bot · 2024-05-24T18:12:52Z

@ahejlsberg
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	₃₀	₃₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_62,154	_62,153	_{-1 (- 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_50,248	_50,242	_{-6 (- 0.01%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{192,864k (± 0.78%)}	_{192,278k (± 0.07%)}	_~	_192,194k	_192,563k	_{p=0.689 n=6}
_{Parse Time}	_{1.55s (± 1.40%)}	_{1.56s (± 1.26%)}	_~	_1.53s	_1.58s	_{p=0.467 n=6}
_{Bind Time}	_{0.86s (± 0.97%)}	_{0.86s (± 1.59%)}	_~	_0.85s	_0.88s	_{p=1.000 n=6}
_{Check Time}	_{11.33s (± 0.29%)}	_{11.31s (± 0.36%)}	_~	_11.26s	_11.37s	_{p=0.571 n=6}
_{Emit Time}	_{3.13s (± 1.26%)}	_{3.14s (± 0.16%)}	_~	_3.14s	_3.15s	_{p=0.560 n=6}
_{Total Time}	_{16.87s (± 0.39%)}	_{16.88s (± 0.16%)}	_~	_16.84s	_16.92s	_{p=0.687 n=6}
_{angular-1 - node (v18.15.0, x64)}
_Errors	₅	₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_944,110	_944,105	_{-5 (- 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_407,140	_407,032	_{-108 (- 0.03%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{1,222,010k (± 0.00%)}	_{1,222,031k (± 0.01%)}	_~	_1,221,879k	_1,222,127k	_{p=0.298 n=6}
_{Parse Time}	_{8.10s (± 0.47%)}	_{8.12s (± 0.52%)}	_~	_8.06s	_8.17s	_{p=0.466 n=6}
_{Bind Time}	_{2.24s (± 0.67%)}	_{2.25s (± 0.79%)}	_~	_2.23s	_2.28s	_{p=0.190 n=6}
_{Check Time}	_{36.61s (± 0.52%)}	_{36.54s (± 0.64%)}	_~	_36.30s	_36.88s	_{p=0.378 n=6}
_{Emit Time}	_{17.54s (± 0.79%)}	_{17.57s (± 0.76%)}	_~	_17.40s	_17.76s	_{p=0.748 n=6}
_{Total Time}	_{64.48s (± 0.25%)}	_{64.47s (± 0.41%)}	_~	_64.25s	_64.92s	_{p=0.575 n=6}
_{mui-docs - node (v18.15.0, x64)}
_Errors	₅	₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,982,501	_1,982,496	_{-5 (- 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_882,099	_882,085	_{-14 (- 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{1,886,154k (± 0.00%)}	_{1,886,053k (± 0.00%)}	_{-101k (- 0.01%)}	_1,886,025k	_1,886,073k	_{p=0.005 n=6}
_{Parse Time}	_{6.79s (± 0.25%)}	_{6.80s (± 0.50%)}	_~	_6.77s	_6.85s	_{p=0.685 n=6}
_{Bind Time}	_{2.30s (± 0.93%)}	_{2.30s (± 0.80%)}	_~	_2.28s	_2.33s	_{p=0.867 n=6}
_{Check Time}	_{60.56s (± 0.29%)}	_{60.56s (± 0.37%)}	_~	_60.25s	_60.80s	_{p=0.936 n=6}
_{Emit Time}	_{0.14s (± 4.05%)}	_0.14s	_~	_~	_~	_{p=0.071 n=6}
_{Total Time}	_{69.78s (± 0.27%)}	_{69.79s (± 0.36%)}	_~	_69.45s	_70.08s	_{p=1.000 n=6}
_{self-build-src - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,225,780	_1,225,756	_{-24 (- 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_260,772	_260,634	_{-138 (- 0.05%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,343,388k (± 0.07%)}	_{2,343,249k (± 0.03%)}	_~	_2,342,377k	_2,344,432k	_{p=0.689 n=6}
_{Parse Time}	_{7.50s (± 1.30%)}	_{7.39s (± 1.05%)}	_~	_7.30s	_7.49s	_{p=0.077 n=6}
_{Bind Time}	_{2.80s (± 0.37%)}	_{2.79s (± 0.73%)}	_~	_2.76s	_2.81s	_{p=0.627 n=6}
_{Check Time}	_{49.43s (± 0.72%)}	_{49.29s (± 0.27%)}	_~	_49.08s	_49.44s	_{p=0.689 n=6}
_{Emit Time}	_{3.75s (± 4.02%)}	_{3.82s (± 5.72%)}	_~	_3.65s	_4.24s	_{p=0.470 n=6}
_{Total Time}	_{63.49s (± 0.93%)}	_{63.31s (± 0.50%)}	_~	_62.97s	_63.84s	_{p=0.810 n=6}
_{self-build-src-public-api - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,225,780	_1,225,756	_{-24 (- 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_260,772	_260,634	_{-138 (- 0.05%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,454,143k (± 2.46%)}	_{2,468,547k (± 3.16%)}	_~	_2,416,964k	_2,569,375k	_{p=0.810 n=6}
_{Parse Time}	_{6.26s (± 1.04%)}	_{6.22s (± 0.90%)}	_~	_6.13s	_6.28s	_{p=0.378 n=6}
_{Bind Time}	_{2.04s (± 0.20%)}	_{2.04s (± 0.67%)}	_~	_2.02s	_2.06s	_{p=0.667 n=6}
_{Check Time}	_{40.25s (± 0.43%)}	_{40.37s (± 0.61%)}	_~	_40.12s	_40.80s	_{p=0.471 n=6}
_{Emit Time}	_{3.12s (± 7.47%)}	_{3.10s (± 3.84%)}	_~	_2.94s	_3.21s	_{p=0.936 n=6}
_{Total Time}	_{51.69s (± 0.72%)}	_{51.73s (± 0.59%)}	_~	_51.39s	_52.28s	_{p=0.575 n=6}
_{self-compiler - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_258,042	_258,030	_{-12 (- 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_104,983	_104,903	_{-80 (- 0.08%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{426,861k (± 0.02%)}	_{426,797k (± 0.01%)}	_~	_426,720k	_426,828k	_{p=0.078 n=6}
_{Parse Time}	_{4.17s (± 0.47%)}	_{4.16s (± 0.71%)}	_~	_4.12s	_4.19s	_{p=0.627 n=6}
_{Bind Time}	_{1.62s (± 0.65%)}	_{1.63s (± 0.63%)}	_~	_1.61s	_1.64s	_{p=0.098 n=6}
_{Check Time}	_{22.25s (± 0.52%)}	_{22.25s (± 0.60%)}	_~	_22.09s	_22.39s	_{p=0.936 n=6}
_{Emit Time}	_{1.65s (± 1.65%)}	_{1.70s (± 0.89%)}	_{+0.04s (+ 2.42%)}	_1.68s	_1.72s	_{p=0.023 n=6}
_{Total Time}	_{29.69s (± 0.37%)}	_{29.72s (± 0.50%)}	_~	_29.55s	_29.91s	_{p=0.872 n=6}
_{ts-pre-modules - node (v18.15.0, x64)}
_Errors	₃₅	₃₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_224,575	_224,565	_{-10 (- 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_93,785	_93,734	_{-51 (- 0.05%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{369,783k (± 0.02%)}	_{369,851k (± 0.02%)}	_~	_369,746k	_369,964k	_{p=0.173 n=6}
_{Parse Time}	_{3.50s (± 0.93%)}	_{3.49s (± 1.08%)}	_~	_3.44s	_3.53s	_{p=0.688 n=6}
_{Bind Time}	_{1.93s (± 1.16%)}	_{1.92s (± 1.11%)}	_~	_1.90s	_1.95s	_{p=0.370 n=6}
_{Check Time}	_{19.37s (± 0.29%)}	_{19.35s (± 0.45%)}	_~	_19.26s	_19.50s	_{p=0.574 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{24.81s (± 0.29%)}	_{24.76s (± 0.38%)}	_~	_24.60s	_24.88s	_{p=0.421 n=6}
_{vscode - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,836,660	_2,836,658	_{-2 (- 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_961,296	_960,774	_{-522 (- 0.05%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{3,009,142k (± 0.00%)}	_{3,008,946k (± 0.00%)}	_{-196k (- 0.01%)}	_3,008,894k	_3,008,978k	_{p=0.005 n=6}
_{Parse Time}	_{13.82s (± 0.23%)}	_{13.83s (± 0.25%)}	_~	_13.79s	_13.88s	_{p=0.872 n=6}
_{Bind Time}	_{4.16s (± 0.29%)}	_{4.16s (± 0.39%)}	_~	_4.14s	_4.19s	_{p=0.319 n=6}
_{Check Time}	_{74.78s (± 2.78%)}	_{74.10s (± 2.09%)}	_~	_73.36s	_77.25s	_{p=0.810 n=6}
_{Emit Time}	_{22.27s (± 9.00%)}	_{23.06s (± 6.89%)}	_~	_19.83s	_23.95s	_{p=0.149 n=6}
_{Total Time}	_{115.03s (± 0.19%)}	_{115.15s (± 0.26%)}	_~	_114.93s	_115.74s	_{p=0.810 n=6}
_{webpack - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_266,087	_266,048	_{-39 (- 0.01%)}	_~	_~	_{p=0.001 n=6}
_Types	_108,518	_108,470	_{-48 (- 0.04%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{410,989k (± 0.03%)}	_{410,812k (± 0.02%)}	_{-176k (- 0.04%)}	_410,739k	_410,919k	_{p=0.045 n=6}
_{Parse Time}	_{3.86s (± 1.21%)}	_{3.82s (± 1.20%)}	_~	_3.75s	_3.89s	_{p=0.226 n=6}
_{Bind Time}	_{1.66s (± 0.59%)}	_{1.66s (± 0.38%)}	_~	_1.65s	_1.67s	_{p=0.733 n=6}
_{Check Time}	_{17.01s (± 0.55%)}	_{17.02s (± 0.48%)}	_~	_16.90s	_17.10s	_{p=0.936 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{22.53s (± 0.54%)}	_{22.50s (± 0.42%)}	_~	_22.35s	_22.59s	_{p=0.871 n=6}
_{xstate-main - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_535,745	_535,743	_{-2 (- 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_182,753	_182,738	_{-15 (- 0.01%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{470,420k (± 0.01%)}	_{470,404k (± 0.01%)}	_~	_470,335k	_470,460k	_{p=0.575 n=6}
_{Parse Time}	_{3.17s (± 0.83%)}	_{3.16s (± 0.24%)}	_~	_3.15s	_3.17s	_{p=0.279 n=6}
_{Bind Time}	_{1.20s (± 0.97%)}	_{1.20s (± 0.43%)}	_~	_1.19s	_1.20s	_{p=0.542 n=6}
_{Check Time}	_{18.36s (± 0.31%)}	_{18.33s (± 0.38%)}	_~	_18.25s	_18.45s	_{p=0.423 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{22.72s (± 0.18%)}	_{22.69s (± 0.31%)}	_~	_22.61s	_22.81s	_{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

DanielRosenwasser · 2024-05-24T18:34:11Z

tests/baselines/reference/complexRecursiveCollections.types

@@ -3,7 +3,7 @@
 === Performance Stats ===
 Assignability cache: 10,000
 Type Count: 50,000
-Instantiation count: 250,000
+Instantiation count: 100,000


DanielRosenwasser · 2024-05-24T18:46:05Z

tests/baselines/reference/flatArrayNoExcessiveStackDepth.errors.txt

@@ -28,7 +28,7 @@ flatArrayNoExcessiveStackDepth.ts(20,5): error TS2322: Type 'FlatArray<Arr, any>
 ~
 !!! error TS2322: Type 'FlatArray<Arr, any>' is not assignable to type 'FlatArray<Arr, D>'.
 !!! error TS2322: Type 'Arr' is not assignable to type 'FlatArray<Arr, D>'.
-!!! error TS2322: Type 'Arr' is not assignable to type '(Arr extends readonly (infer InnerArr)[] ? FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][D]> : Arr) & Arr'.
+!!! error TS2322: Type 'Arr' is not assignable to type 'Arr & (Arr extends readonly (infer InnerArr)[] ? FlatArray<InnerArr, [-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20][D]> : Arr)'.


I'm guessing that because a return type was not eagerly calculated at some step, one of these types was created later than the other.

Though we don't sort type IDs in intersections, so that's not it.

I'm sure it's a case of a distributing over a union type and turning it into an intersection type in a write-position. We do that in several places in type simplification and type relations. For example, an indexed access type T[K], where K is a union type, occurring in a write-position.

DanielRosenwasser · 2024-05-24T19:07:35Z

@typescript-bot pack this

typescript-bot · 2024-05-24T19:07:38Z

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

Command	Status	Results
`pack this`	✅ Started	✅ Results

typescript-bot · 2024-05-24T19:12:09Z

Hey @DanielRosenwasser, 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/161926/artifacts?artifactName=tgz&fileId=7C4C88D3CC0BAE62E2E916143B8B1846083A315541F261C3DA38959E4EF3190402&fileName=/typescript-5.5.0-insiders.20240524.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 · 2024-05-24T19:12:27Z

@ahejlsberg Here are the results of running the top 400 repos comparing main and refs/pull/58650/merge:

Something interesting changed - please have a look.

Details

tinacms/tinacms

11 of 24 projects failed to build with the old tsc and were ignored

packages/@tinacms/cli/tsconfig.json

error TS2322: Type '(ctx: ts.TransformationContext) => (node: ts.Node) => ts.Node' is not assignable to type 'TransformerFactory<SourceFile>'.
- packages/@tinacms/cli/src/cmds/init/codegen/index.ts#L200
- packages/@tinacms/cli/src/cmds/init/codegen/index.ts#L304

DanielRosenwasser · 2024-05-24T19:40:56Z

The Webpack change is that there are now two implicit any errors instead of just one.

ahejlsberg · 2024-05-24T23:34:57Z

The Webpack change is that there are now two implicit any errors instead of just one.

Looks to me like we now get a bit deeper in type resolution before detecting the circularity in here, and thus we report an error in one more place (because the resolution stack is one level deeper). This actually improves the error reporting because it makes it easier to see what causes the circularity.

ahejlsberg · 2024-05-26T16:27:47Z

The new errors in the tinacms repo result from the absence of circularities that previously caused arrow functions to have implicit any return types. The repo has noImplicitAny turned off, so those circularities would simply go unreported and the types would become very permissive. With this PR, the circularities are gone, the types are actually what they should be, and appropriate errors are reported.

ahejlsberg · 2024-05-26T16:29:36Z

I think this is ready to merge. Performance is unaffected and the new test suite errors in are all desirable and correct.

ahejlsberg added 3 commits May 24, 2024 10:21

Only resolve source return type when actually needed during inference

317eeae

Accept new baselines

6e3d434

Add regression test

feba86d

typescript-bot assigned ahejlsberg May 24, 2024

typescript-bot added Author: Team For Uncommitted Bug PR for untriaged, rejected, closed or missing bug labels May 24, 2024

Merge branch 'main' into fix58616

0e28408

# Conflicts: # tests/baselines/reference/circularReferenceInReturnType.types

ahejlsberg requested review from DanielRosenwasser and RyanCavanaugh May 24, 2024 17:38

DanielRosenwasser reviewed May 24, 2024

View reviewed changes

gabritto approved these changes May 27, 2024

View reviewed changes

ahejlsberg merged commit 1d026a9 into main May 28, 2024
28 checks passed

ahejlsberg deleted the fix58616 branch May 28, 2024 15:10

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Only resolve source return type when actually needed during inference #58650

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Only resolve source return type when actually needed during inference #58650

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