Check if switch statements are exhaustive when their expressions is generic with a literal type constraint by Andarist · Pull Request #60644 · microsoft/TypeScript

Andarist · 2024-11-30T11:58:50Z

cc @gabritto since it's somewhat related to #56941

…eneric with a literal type constraint

typescript-bot · 2024-11-30T11:58:53Z

This PR doesn't have any linked issues. Please open an issue that references this PR. From there we can discuss and prioritise.

jfet97 · 2024-11-30T12:05:13Z

That "person" case is suspiciously familiar :P
Btw thanks :D

Jontii · 2024-12-02T06:27:21Z

Would love this

jfet97 · 2024-12-02T13:22:58Z

Would fix #60658

gabritto · 2024-12-02T17:13:49Z

@typescript-bot test it

typescript-bot · 2024-12-02T17:13:54Z

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 · 2024-12-02T17:35:52Z

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

Everything looks the same!

You can check the log here.

typescript-bot · 2024-12-02T17:36:46Z

@gabritto Here are the results of running the user tests with tsc comparing main and refs/pull/60644/merge:

Everything looks good!

typescript-bot · 2024-12-02T17:56:43Z

@gabritto
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	_62,363	_62,363	_~	_~	_~	_{p=1.000 n=6}
_Types	_50,395	_50,395	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{193,618k (± 0.75%)}	_{193,636k (± 0.76%)}	_~	_193,007k	_196,637k	_{p=0.378 n=6}
_{Parse Time}	_{1.31s (± 0.89%)}	_{1.31s (± 0.92%)}	_~	_1.29s	_1.32s	_{p=0.388 n=6}
_{Bind Time}	_0.72s	_0.72s	_~	_~	_~	_{p=1.000 n=6}
_{Check Time}	_{9.83s (± 0.51%)}	_{9.80s (± 0.56%)}	_~	_9.73s	_9.87s	_{p=0.377 n=6}
_{Emit Time}	_{2.74s (± 1.31%)}	_{2.73s (± 0.52%)}	_~	_2.71s	_2.75s	_{p=0.934 n=6}
_{Total Time}	_{14.59s (± 0.29%)}	_{14.56s (± 0.36%)}	_~	_14.48s	_14.61s	_{p=0.518 n=6}
_{angular-1 - node (v18.15.0, x64)}
_Errors	₃₇	₃₇	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_947,936	_947,936	_~	_~	_~	_{p=1.000 n=6}
_Types	_410,955	_410,955	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{1,225,985k (± 0.00%)}	_{1,226,011k (± 0.00%)}	_~	_1,225,989k	_1,226,048k	_{p=0.065 n=6}
_{Parse Time}	_{6.67s (± 0.65%)}	_{6.66s (± 0.64%)}	_~	_6.61s	_6.71s	_{p=0.809 n=6}
_{Bind Time}	_{1.88s (± 0.29%)}	_{1.88s (± 0.40%)}	_~	_1.87s	_1.89s	_{p=0.476 n=6}
_{Check Time}	_{31.98s (± 0.40%)}	_{32.04s (± 0.41%)}	_~	_31.80s	_32.18s	_{p=0.335 n=6}
_{Emit Time}	_{15.17s (± 0.49%)}	_{15.16s (± 0.42%)}	_~	_15.09s	_15.24s	_{p=1.000 n=6}
_{Total Time}	_{55.70s (± 0.28%)}	_{55.75s (± 0.28%)}	_~	_55.47s	_55.90s	_{p=0.630 n=6}
_{mui-docs - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,501,661	_2,501,661	_~	_~	_~	_{p=1.000 n=6}
_Types	_909,610	_909,610	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,319,041k (± 0.00%)}	_{2,319,069k (± 0.00%)}	_~	_2,319,030k	_2,319,098k	_{p=0.148 n=6}
_{Parse Time}	_{9.30s (± 0.29%)}	_{9.29s (± 0.27%)}	_~	_9.26s	_9.32s	_{p=1.000 n=6}
_{Bind Time}	_{2.15s (± 0.64%)}	_{2.17s (± 0.74%)}	_~	_2.14s	_2.18s	_{p=0.140 n=6}
_{Check Time}	_{74.89s (± 0.49%)}	_{75.08s (± 1.54%)}	_~	_73.47s	_77.04s	_{p=0.810 n=6}
_{Emit Time}	_{0.28s (± 2.26%)}	_{0.29s (± 4.29%)}	_~	_0.27s	_0.30s	_{p=0.591 n=6}
_{Total Time}	_{86.63s (± 0.41%)}	_{86.83s (± 1.33%)}	_~	_85.27s	_88.83s	_{p=0.936 n=6}
_{self-build-src - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,225,251	_1,225,251	_~	_~	_~	_{p=1.000 n=6}
_Types	_266,546	_266,546	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,354,183k (± 0.03%)}	_{2,354,055k (± 0.02%)}	_~	_2,353,579k	_2,354,515k	_{p=0.936 n=6}
_{Parse Time}	_{5.23s (± 1.20%)}	_{5.21s (± 0.69%)}	_~	_5.17s	_5.26s	_{p=0.335 n=6}
_{Bind Time}	_{1.78s (± 0.84%)}	_{1.77s (± 1.13%)}	_~	_1.75s	_1.80s	_{p=0.288 n=6}
_{Check Time}	_{35.22s (± 0.28%)}	_{35.21s (± 0.11%)}	_~	_35.16s	_35.25s	_{p=0.688 n=6}
_{Emit Time}	_{3.03s (± 3.77%)}	_{2.96s (± 1.51%)}	_~	_2.89s	_3.02s	_{p=0.261 n=6}
_{Total Time}	_{45.28s (± 0.34%)}	_{45.18s (± 0.09%)}	_~	_45.12s	_45.24s	_{p=0.378 n=6}
_{self-build-src-public-api - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,225,251	_1,225,251	_~	_~	_~	_{p=1.000 n=6}
_Types	_266,546	_266,546	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{3,028,519k (± 9.75%)}	_{2,908,400k (±12.88%)}	_~	_2,423,421k	_3,150,982k	_{p=0.298 n=6}
_{Parse Time}	_{6.96s (± 1.54%)}	_{6.97s (± 2.00%)}	_~	_6.78s	_7.12s	_{p=0.575 n=6}
_{Bind Time}	_{2.15s (± 2.08%)}	_{2.15s (± 1.40%)}	_~	_2.10s	_2.18s	_{p=0.936 n=6}
_{Check Time}	_{42.80s (± 0.37%)}	_{42.94s (± 0.52%)}	_~	_42.67s	_43.27s	_{p=0.378 n=6}
_{Emit Time}	_{3.50s (± 2.04%)}	_{3.49s (± 3.59%)}	_~	_3.40s	_3.73s	_{p=0.575 n=6}
_{Total Time}	_{55.41s (± 0.41%)}	_{55.55s (± 0.59%)}	_~	_55.01s	_55.99s	_{p=0.230 n=6}
_{self-compiler - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_262,223	_262,223	_~	_~	_~	_{p=1.000 n=6}
_Types	_106,607	_106,607	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{439,832k (± 0.01%)}	_{439,799k (± 0.01%)}	_~	_439,701k	_439,856k	_{p=0.378 n=6}
_{Parse Time}	_{3.53s (± 0.43%)}	_{3.53s (± 0.77%)}	_~	_3.50s	_3.57s	_{p=1.000 n=6}
_{Bind Time}	_{1.31s (± 0.62%)}	_{1.31s (± 1.40%)}	_~	_1.28s	_1.33s	_{p=0.801 n=6}
_{Check Time}	_{18.89s (± 0.34%)}	_{18.88s (± 0.24%)}	_~	_18.82s	_18.94s	_{p=0.687 n=6}
_{Emit Time}	_{1.52s (± 1.34%)}	_{1.53s (± 1.64%)}	_~	_1.50s	_1.57s	_{p=1.000 n=6}
_{Total Time}	_{25.25s (± 0.28%)}	_{25.24s (± 0.19%)}	_~	_25.19s	_25.30s	_{p=0.936 n=6}
_{ts-pre-modules - node (v18.15.0, x64)}
_Errors	₇₀	₇₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_226,062	_226,062	_~	_~	_~	_{p=1.000 n=6}
_Types	_94,488	_94,488	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{371,661k (± 0.04%)}	_{371,689k (± 0.06%)}	_~	_371,495k	_371,988k	_{p=0.810 n=6}
_{Parse Time}	_{2.90s (± 1.62%)}	_{2.87s (± 0.42%)}	_~	_2.85s	_2.88s	_{p=0.331 n=6}
_{Bind Time}	_{1.58s (± 1.29%)}	_{1.58s (± 0.77%)}	_~	_1.57s	_1.60s	_{p=0.745 n=6}
_{Check Time}	_{16.48s (± 0.41%)}	_{16.48s (± 0.23%)}	_~	_16.43s	_16.53s	_{p=0.936 n=6}
_{Emit Time}	_0.00s	_{0.00s (±244.70%)}	_~	_0.00s	_0.01s	_{p=0.405 n=6}
_{Total Time}	_{20.97s (± 0.37%)}	_{20.94s (± 0.26%)}	_~	_20.87s	_21.01s	_{p=0.629 n=6}
_{vscode - node (v18.15.0, x64)}
_Errors	₄	₄	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_3,188,837	_3,188,837	_~	_~	_~	_{p=1.000 n=6}
_Types	_1,096,744	_1,096,744	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{3,263,160k (± 0.01%)}	_{3,263,009k (± 0.01%)}	_~	_3,262,590k	_3,263,645k	_{p=0.471 n=6}
_{Parse Time}	_{14.15s (± 0.77%)}	_{14.11s (± 0.41%)}	_~	_14.04s	_14.20s	_{p=0.335 n=6}
_{Bind Time}	_{4.60s (± 3.05%)}	_{4.68s (± 2.49%)}	_~	_4.52s	_4.77s	_{p=0.519 n=6}
_{Check Time}	_{89.03s (± 3.25%)}	_{86.44s (± 0.64%)}	_~	_85.60s	_87.05s	_{p=0.109 n=6}
_{Emit Time}	_{26.77s (±10.67%)}	_{28.31s (± 2.64%)}	_~	_27.27s	_28.90s	_{p=0.810 n=6}
_{Total Time}	_{134.55s (± 0.86%)}	_{133.54s (± 0.87%)}	_~	_131.82s	_134.55s	_{p=0.173 n=6}
_{webpack - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_288,733	_288,733	_~	_~	_~	_{p=1.000 n=6}
_Types	_117,152	_117,152	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{440,955k (± 0.04%)}	_{441,009k (± 0.03%)}	_~	_440,883k	_441,242k	_{p=0.298 n=6}
_{Parse Time}	_{4.10s (± 0.51%)}	_{4.08s (± 0.51%)}	_~	_4.06s	_4.11s	_{p=0.289 n=6}
_{Bind Time}	_{1.75s (± 3.21%)}	_{1.74s (± 1.34%)}	_~	_1.71s	_1.77s	_{p=0.810 n=6}
_{Check Time}	_{18.87s (± 0.42%)}	_{18.88s (± 0.29%)}	_~	_18.80s	_18.95s	_{p=0.936 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{24.72s (± 0.52%)}	_{24.71s (± 0.27%)}	_~	_24.62s	_24.78s	_{p=0.689 n=6}
_{xstate-main - node (v18.15.0, x64)}
_Errors	₅	₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_552,390	_552,390	_~	_~	_~	_{p=1.000 n=6}
_Types	_185,096	_185,096	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{492,423k (± 0.03%)}	_{492,461k (± 0.04%)}	_~	_492,112k	_492,640k	_{p=0.689 n=6}
_{Parse Time}	_{3.40s (± 0.73%)}	_{3.42s (± 0.35%)}	_~	_3.41s	_3.44s	_{p=0.283 n=6}
_{Bind Time}	_{1.18s (± 1.03%)}	_{1.17s (± 1.17%)}	_~	_1.16s	_1.19s	_{p=0.286 n=6}
_{Check Time}	_{19.65s (± 1.25%)}	_{19.55s (± 0.85%)}	_~	_19.40s	_19.86s	_{p=0.630 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{24.24s (± 1.02%)}	_{24.14s (± 0.65%)}	_~	_24.01s	_24.44s	_{p=0.521 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 · 2024-12-02T18:42:51Z

@gabritto Here are the results of running the top 400 repos with tsc comparing main and refs/pull/60644/merge:

Everything looks good!

gabritto · 2024-12-02T19:05:48Z

@typescript-bot pack this

typescript-bot · 2024-12-02T19:05:53Z

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

Command	Status	Results
`pack this`	✅ Started	✅ Results

typescript-bot · 2024-12-02T19:07:51Z

Hey @gabritto, 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/164255/artifacts?artifactName=tgz&fileId=EE4806BE35BC77ED3673245ECA2612801A455CE794E0A2BBF4926021973E02A302&fileName=/typescript-5.8.0-insiders.20241202.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@5.8.0-pr-60644-12".;

Check if switch statements are exhaustive when their expressions is g…

f156d5e

…eneric with a literal type constraint

typescript-bot added the For Uncommitted Bug PR for untriaged, rejected, closed or missing bug label Nov 30, 2024

jfet97 mentioned this pull request Dec 2, 2024

Switch statements exhaustiveness check is failing when the expression has generic type but with literal type constraint #60658

Closed

gabritto approved these changes Dec 2, 2024

View reviewed changes

gabritto merged commit 14c65b3 into microsoft:main Dec 2, 2024

sandersn removed this from PR Backlog Apr 22, 2025

Andarist mentioned this pull request Jun 5, 2025

Port "Check if switch statements are exhaustive when their expressions is generic with a literal type constraint" microsoft/typescript-go#1071

Merged

microsoft locked as resolved and limited conversation to collaborators Oct 15, 2025

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