Instantiate earlier inferred constraints in conditional types #57362

Andarist · 2024-02-09T23:34:45Z

some historical related context can be found in #31455 and #42747

jakebailey · 2024-02-09T23:45:30Z

@typescript-bot test top200
@typescript-bot user test this
@typescript-bot run dt

typescript-bot · 2024-02-09T23:45:32Z

Heya @jakebailey, I've started to run the diff-based user code test suite on this PR at 1148bce. You can monitor the build here.

Update: The results are in!

typescript-bot · 2024-02-09T23:45:32Z

Heya @jakebailey, I've started to run the parallelized Definitely Typed test suite on this PR at 1148bce. You can monitor the build here.

Update: The results are in!

typescript-bot · 2024-02-09T23:45:32Z

Heya @jakebailey, I've started to run the faster perf test suite on this PR at 1148bce. You can monitor the build here.

Update: The results are in!

typescript-bot · 2024-02-09T23:45:32Z

Heya @jakebailey, I've started to run the diff-based top-repos suite on this PR at 1148bce. You can monitor the build here.

Update: The results are in!

Andarist · 2024-02-09T23:52:33Z

src/compiler/checker.ts

                //    * The original `mapper` used to create this conditional
-                //    * The mapper that maps the old root type parameter to the clone (`freshMapper`)
-                //    * The mapper that maps the clone to its inference result (`context.mapper`)
-                const freshParams = sameMap(root.inferTypeParameters, maybeCloneTypeParameter);


This PR - in its current form - removes the context of those fresh params.

They were introduced in this PR to address a type parameter leak. From what I understand, the leak was caused by non-instantiated constraints of infer type parameters, and those fresh params were introduced to "wire up" the mapper so it would partake in the instantiation of those constraints. Those instantiations are made using context.nonFixingMapper so I figured out that maybe this can be simplified by combining that with the mapper.

The problem with maybeCloneTypeParameter that was used to create those freshParams is that the check inside it is non-exhaustive:

isGenericObjectType(constraint) || isGenericIndexType(constraint)

When it comes to the added test case, this check doesn't cover Klass<V> - that's neither of the tested things. (when the inferred Klass<number> gets checked against that constraint it fails the assignability check and the inferred result gets replaced by the constraint which in turn is instantiated by the combinedMapper)

So the alternative fix would be to extend this check to cover more situations. That can't be done exhaustively and cheaply. The closest check to that is couldContainTypeVariables and that's not supposed to be used in situations like this, it's just an optimization.

So given the fact above, one extra alternative solution comes to mind... freshParams could always be created. I verified that it would fix the issue and that it wouldn't break any existing case.

typescript-bot · 2024-02-10T00:09:34Z

@jakebailey Here are the results of running the user test suite comparing main and refs/pull/57362/merge:

There were infrastructure failures potentially unrelated to your change:

1 instance of "Package install failed"

Otherwise...

Something interesting changed - please have a look.

Details

puppeteer

packages/browsers/test/src/tsconfig.json

[MISSING] error TS2307: Cannot find module '@pptr/testserver' or its corresponding type declarations.
- packages/browsers/test/src/utils.ts#L13 in packages/browsers/test/src/tsconfig.json

typescript-bot · 2024-02-10T00:22:22Z

@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
_{Angular - node (v18.15.0, x64)}
_{Memory used}	_{295,672k (± 0.01%)}	_{295,669k (± 0.01%)}	_~	_295,637k	_295,721k	_{p=0.810 n=6}
_{Parse Time}	_{2.66s (± 0.24%)}	_{2.65s (± 0.55%)}	_~	_2.63s	_2.67s	_{p=0.345 n=6}
_{Bind Time}	_{0.82s (± 0.66%)}	_{0.83s (± 1.92%)}	_~	_0.81s	_0.85s	_{p=0.498 n=6}
_{Check Time}	_{8.21s (± 0.23%)}	_{8.20s (± 0.23%)}	_~	_8.18s	_8.23s	_{p=0.807 n=6}
_{Emit Time}	_{7.10s (± 0.24%)}	_{7.09s (± 0.29%)}	_~	_7.06s	_7.11s	_{p=0.806 n=6}
_{Total Time}	_{18.79s (± 0.17%)}	_{18.78s (± 0.13%)}	_~	_18.74s	_18.81s	_{p=0.333 n=6}
_{Compiler-Unions - node (v18.15.0, x64)}
_{Memory used}	_{193,500k (± 1.55%)}	_{193,897k (± 1.47%)}	_~	_191,464k	_197,360k	_{p=1.000 n=6}
_{Parse Time}	_{1.35s (± 0.47%)}	_{1.36s (± 0.55%)}	_~	_1.35s	_1.37s	_{p=0.081 n=6}
_{Bind Time}	_{0.72s (± 0.00%)}	_{0.72s (± 0.00%)}	_~	_0.72s	_0.72s	_{p=1.000 n=6}
_{Check Time}	_{9.37s (± 0.55%)}	_{9.37s (± 0.24%)}	_~	_9.34s	_9.40s	_{p=0.872 n=6}
_{Emit Time}	_{2.62s (± 0.66%)}	_{2.61s (± 0.59%)}	_~	_2.59s	_2.63s	_{p=0.461 n=6}
_{Total Time}	_{14.06s (± 0.29%)}	_{14.06s (± 0.12%)}	_~	_14.03s	_14.08s	_{p=0.808 n=6}
_{Monaco - node (v18.15.0, x64)}
_{Memory used}	_{347,464k (± 0.00%)}	_{347,467k (± 0.01%)}	_~	_347,436k	_347,488k	_{p=0.574 n=6}
_{Parse Time}	_{2.48s (± 0.72%)}	_{2.47s (± 0.33%)}	_~	_2.46s	_2.48s	_{p=0.324 n=6}
_{Bind Time}	_{0.93s (± 0.56%)}	_{0.92s (± 0.56%)}	_~	_0.92s	_0.93s	_{p=0.311 n=6}
_{Check Time}	_{6.95s (± 0.37%)}	_{6.94s (± 0.30%)}	_~	_6.92s	_6.98s	_{p=0.418 n=6}
_{Emit Time}	_{4.06s (± 0.61%)}	_{4.07s (± 0.55%)}	_~	_4.03s	_4.09s	_{p=0.684 n=6}
_{Total Time}	_{14.42s (± 0.16%)}	_{14.40s (± 0.24%)}	_~	_14.34s	_14.44s	_{p=0.462 n=6}
_{TFS - node (v18.15.0, x64)}
_{Memory used}	_{302,857k (± 0.00%)}	_{302,849k (± 0.00%)}	_~	_302,824k	_302,861k	_{p=0.422 n=6}
_{Parse Time}	_{2.02s (± 0.73%)}	_{2.02s (± 0.52%)}	_~	_2.01s	_2.04s	_{p=0.805 n=6}
_{Bind Time}	_{1.00s (± 0.81%)}	_{1.00s (± 0.98%)}	_~	_0.99s	_1.02s	_{p=0.673 n=6}
_{Check Time}	_{6.34s (± 0.44%)}	_{6.34s (± 0.41%)}	_~	_6.30s	_6.37s	_{p=0.936 n=6}
_{Emit Time}	_{3.60s (± 0.38%)}	_{3.60s (± 0.42%)}	_~	_3.59s	_3.63s	_{p=1.000 n=6}
_{Total Time}	_{12.96s (± 0.24%)}	_{12.97s (± 0.30%)}	_~	_12.91s	_13.00s	_{p=0.935 n=6}
_{material-ui - node (v18.15.0, x64)}
_{Memory used}	_{511,369k (± 0.00%)}	_{511,378k (± 0.01%)}	_~	_511,346k	_511,421k	_{p=0.689 n=6}
_{Parse Time}	_{2.64s (± 0.66%)}	_{2.65s (± 0.62%)}	_~	_2.63s	_2.67s	_{p=0.281 n=6}
_{Bind Time}	_{0.99s (± 0.55%)}	_{1.00s (± 0.82%)}	_~	_0.99s	_1.01s	_{p=0.859 n=6}
_{Check Time}	_{17.25s (± 0.33%)}	_{17.34s (± 0.43%)}	_~	_17.25s	_17.43s	_{p=0.054 n=6}
_{Emit Time}	_{0.00s (± 0.00%)}	_{0.00s (± 0.00%)}	_~	_0.00s	_0.00s	_{p=1.000 n=6}
_{Total Time}	_{20.88s (± 0.29%)}	_{20.99s (± 0.41%)}	_{+0.11s (+ 0.53%)}	_20.87s	_21.09s	_{p=0.045 n=6}
_{mui-docs - node (v18.15.0, x64)}
_{Memory used}	_{2,269,547k (± 0.00%)}	_{2,269,595k (± 0.00%)}	_{+48k (+ 0.00%)}	_2,269,565k	_2,269,627k	_{p=0.010 n=6}
_{Parse Time}	_{11.86s (± 0.61%)}	_{11.92s (± 0.73%)}	_~	_11.86s	_12.09s	_{p=0.092 n=6}
_{Bind Time}	_{2.64s (± 0.32%)}	_{2.65s (± 0.32%)}	_~	_2.63s	_2.65s	_{p=0.084 n=6}
_{Check Time}	_{101.19s (± 0.63%)}	_{101.04s (± 0.58%)}	_~	_100.33s	_101.66s	_{p=0.689 n=6}
_{Emit Time}	_{0.32s (± 1.28%)}	_{0.32s (± 1.28%)}	_~	_0.31s	_0.32s	_{p=1.000 n=6}
_{Total Time}	_{116.01s (± 0.55%)}	_{115.93s (± 0.45%)}	_~	_115.26s	_116.53s	_{p=0.936 n=6}
_{self-build-src - node (v18.15.0, x64)}
_{Memory used}	_{2,414,079k (± 0.01%)}	_{2,413,593k (± 0.01%)}	_{-486k (- 0.02%)}	_2,413,304k	_2,413,888k	_{p=0.013 n=6}
_{Parse Time}	_{4.94s (± 1.01%)}	_{4.91s (± 0.30%)}	_~	_4.89s	_4.92s	_{p=0.422 n=6}
_{Bind Time}	_{1.88s (± 1.00%)}	_{1.86s (± 0.65%)}	_~	_1.84s	_1.87s	_{p=0.104 n=6}
_{Check Time}	_{33.39s (± 0.22%)}	_{33.32s (± 0.25%)}	_~	_33.16s	_33.38s	_{p=0.229 n=6}
_{Emit Time}	_{2.70s (± 1.60%)}	_{2.66s (± 0.63%)}	_{-0.04s (- 1.42%)}	_2.65s	_2.69s	_{p=0.044 n=6}
_{Total Time}	_{42.92s (± 0.20%)}	_{42.77s (± 0.20%)}	_{-0.15s (- 0.35%)}	_42.60s	_42.81s	_{p=0.008 n=6}
_{self-compiler - node (v18.15.0, x64)}
_{Memory used}	_{418,763k (± 0.01%)}	_{418,795k (± 0.01%)}	_~	_418,708k	_418,896k	_{p=0.230 n=6}
_{Parse Time}	_{2.79s (± 2.62%)}	_{2.82s (± 2.99%)}	_~	_2.66s	_2.89s	_{p=0.166 n=6}
_{Bind Time}	_{1.10s (± 4.91%)}	_{1.11s (± 5.54%)}	_~	_1.08s	_1.23s	_{p=0.599 n=6}
_{Check Time}	_{15.10s (± 0.20%)}	_{15.11s (± 0.24%)}	_~	_15.05s	_15.16s	_{p=0.933 n=6}
_{Emit Time}	_{1.14s (± 0.90%)}	_{1.13s (± 0.91%)}	_~	_1.12s	_1.15s	_{p=0.134 n=6}
_{Total Time}	_{20.14s (± 0.16%)}	_{20.17s (± 0.13%)}	_~	_20.13s	_20.20s	_{p=0.107 n=6}
_{vscode - node (v18.15.0, x64)}
_{Memory used}	_{2,828,957k (± 0.00%)}	_{2,828,985k (± 0.00%)}	_~	_2,828,940k	_2,829,025k	_{p=0.336 n=6}
_{Parse Time}	_{10.74s (± 0.54%)}	_{10.71s (± 0.39%)}	_~	_10.67s	_10.77s	_{p=0.421 n=6}
_{Bind Time}	_{3.42s (± 0.16%)}	_{3.43s (± 0.44%)}	_~	_3.41s	_3.45s	_{p=0.865 n=6}
_{Check Time}	_{59.83s (± 0.49%)}	_{60.07s (± 0.45%)}	_~	_59.74s	_60.47s	_{p=0.128 n=6}
_{Emit Time}	_{16.24s (± 0.21%)}	_{16.18s (± 0.31%)}	_~	_16.11s	_16.24s	_{p=0.076 n=6}
_{Total Time}	_{90.23s (± 0.35%)}	_{90.39s (± 0.30%)}	_~	_90.04s	_90.79s	_{p=0.298 n=6}
_{webpack - node (v18.15.0, x64)}
_{Memory used}	_{393,995k (± 0.01%)}	_{393,973k (± 0.01%)}	_~	_393,923k	_394,044k	_{p=0.378 n=6}
_{Parse Time}	_{3.10s (± 0.56%)}	_{3.11s (± 0.57%)}	_~	_3.08s	_3.13s	_{p=0.255 n=6}
_{Bind Time}	_{1.38s (± 1.25%)}	_{1.38s (± 1.06%)}	_~	_1.37s	_1.40s	_{p=0.933 n=6}
_{Check Time}	_{14.06s (± 0.16%)}	_{14.03s (± 0.14%)}	_~	_14.00s	_14.05s	_{p=0.063 n=6}
_{Emit Time}	_{0.00s (± 0.00%)}	_{0.00s (± 0.00%)}	_~	_0.00s	_0.00s	_{p=1.000 n=6}
_{Total Time}	_{18.54s (± 0.17%)}	_{18.52s (± 0.19%)}	_~	_18.46s	_18.56s	_{p=0.572 n=6}
_{xstate - node (v18.15.0, x64)}
_{Memory used}	_{513,391k (± 0.01%)}	_{513,417k (± 0.01%)}	_~	_513,342k	_513,480k	_{p=0.297 n=6}
_{Parse Time}	_{3.27s (± 0.19%)}	_{3.28s (± 0.25%)}	_~	_3.27s	_3.29s	_{p=0.177 n=6}
_{Bind Time}	_{1.54s (± 0.41%)}	_{1.54s (± 0.35%)}	_~	_1.54s	_1.55s	_{p=0.201 n=6}
_{Check Time}	_{2.86s (± 0.94%)}	_{2.85s (± 0.62%)}	_~	_2.84s	_2.89s	_{p=0.288 n=6}
_{Emit Time}	_{0.08s (± 5.21%)}	_{0.08s (± 4.99%)}	_~	_0.08s	_0.09s	_{p=0.218 n=6}
_{Total Time}	_{7.76s (± 0.34%)}	_{7.76s (± 0.29%)}	_~	_7.74s	_7.80s	_{p=0.872 n=6}

System info unknown

Hosts

node (v18.15.0, x64)

Scenarios

Angular - node (v18.15.0, x64)
Compiler-Unions - node (v18.15.0, x64)
Monaco - node (v18.15.0, x64)
TFS - node (v18.15.0, x64)
material-ui - node (v18.15.0, x64)
mui-docs - node (v18.15.0, x64)
self-build-src - node (v18.15.0, x64)
self-compiler - node (v18.15.0, x64)
vscode - node (v18.15.0, x64)
webpack - node (v18.15.0, x64)
xstate - node (v18.15.0, x64)

_Benchmark	_Name	_Iterations
_Current	_pr	₆
_Baseline	_baseline	₆

Developer Information:

Download Benchmarks

typescript-bot · 2024-02-10T00:31:37Z

Hey @jakebailey, the results of running the DT tests are ready.
Everything looks the same!
You can check the log here.

typescript-bot · 2024-02-10T01:37:25Z

@jakebailey Here are the results of running the top-repos suite comparing main and refs/pull/57362/merge:

Everything looks good!

weswigham

IIRC, I added the maybeCloneTypeParameters bit back when it was supposed that the type identities produced here could be bad for perf. Well, we have much better perf tests now, and they look fine to me, so I think this is pretty fine. Now, there may be some edge case that it effects in an outsized way, but hopefully if/when that comes up, we can come up with something nicer to make that work out, because this has always been a bit off-putting to me.

DanielRosenwasser · 2024-02-16T18:42:28Z

@typescript-bot pack this

typescript-bot · 2024-02-16T18:42:31Z

Heya @DanielRosenwasser, I've started to run the tarball bundle task on this PR at 1148bce. You can monitor the build here.

typescript-bot · 2024-02-16T18:44:14Z

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/159910/artifacts?artifactName=tgz&fileId=600725B4DA2FE9B98C60B880CE153B4BD0F692165EC94F23DE30C48E7F33B05D02&fileName=/typescript-5.4.0-insiders.20240216.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@5.4.0-pr-57362-11".;

Instantiate earlier inferred constraints in conditional types

1148bce

Andarist commented Feb 9, 2024

View reviewed changes

RyanCavanaugh requested a review from ahejlsberg February 10, 2024 00:17

RyanCavanaugh requested a review from weswigham February 10, 2024 00:48

weswigham approved these changes Feb 12, 2024

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DanielRosenwasser mentioned this pull request Feb 16, 2024

Design Meeting Notes, 2/16/2024 #57425

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DanielRosenwasser merged commit feb57c2 into microsoft:main Feb 16, 2024
19 checks passed

Andarist deleted the fully-instantiated-constraints-for-infer-type-params branch February 22, 2024 08:27

This was referenced Aug 26, 2024

Add a test for constraint of an infer type parameter not being fully instantiated previously #59760

Merged

Fixed an issue with constraint of an infer type parameter not being fully instantiatable #54205

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jcalz mentioned this pull request Oct 21, 2024

Can extends [any, any] but not generic which is exactly [any, any] (woks till 5.3.3 breaks from 5.4.5) #60299

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Andarist mentioned this pull request Oct 26, 2024

Fixed local extends constraints of infer type parameters when they can contain type variables #60345

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Instantiate earlier inferred constraints in conditional types #57362

Instantiate earlier inferred constraints in conditional types #57362

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Instantiate earlier inferred constraints in conditional types #57362

Instantiate earlier inferred constraints in conditional types #57362

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