Make identity comparison reflexive across unions or intersections of the same type #60868

MichaelMitchell-at · 2024-12-29T07:49:01Z

Please verify that:

There is an associated issue in the Backlog milestone (required) - No one has created an issue for this specifically, but it is a subset of a larger set of problems discussed in [Feature request]type level equal operator #27024 and can be seen as complementary to Merge trivially mergeable intersection types for identity comparison #60726
Code is up-to-date with the main branch
You've successfully run hereby runtests locally
There are new or updated unit tests validating the change

#60726 (comment) points out why some type testing libraries define equality with a definition like:

type Equals<A, B> = (<T>() => T extends (B & T) | T ? 1 : 0) extends (<T>() => T extends (A & T) | T ? 1 : 0) ? true : false;

rather than just

type Equals<A, B> = (<T>() => T extends B ? 1 : 0) extends (<T>() => T extends A ? 1 : 0) ? true : false;

which is that types like {a: 1} are not considered identical to types like {a: 1} & {a: 1} and {a: 1} | {a: 1}.

The latter definition of Equals is required to enable #60726, so I've made this PR to eliminate the need for the former definition of Equals.

typescript-bot · 2024-12-29T07:49:05Z

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

…the same type

MichaelMitchell-at · 2025-01-13T20:47:10Z

@jakebailey @RyanCavanaugh don't know if there's any interest in this, but mind kicking off tests?

jakebailey · 2025-01-13T20:52:43Z

I can at least run the tests

@typescript-bot test it

typescript-bot · 2025-01-13T20:52:47Z

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 · 2025-01-13T21:10:50Z

@jakebailey Here are the results of running the user tests with tsc comparing main and refs/pull/60868/merge:

Everything looks good!

typescript-bot · 2025-01-13T21:14:51Z

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

Everything looks the same!

You can check the log here.

typescript-bot · 2025-01-13T21:35:55Z

@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	_62,390	_~	_~	_~	_{p=1.000 n=6}
_Types	_50,395	_50,395	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{193,773k (± 0.75%)}	_{193,752k (± 0.81%)}	_~	_193,083k	_196,941k	_{p=0.873 n=6}
_{Parse Time}	_{1.31s (± 0.31%)}	_{1.31s (± 0.31%)}	_~	_1.31s	_1.32s	_{p=0.218 n=6}
_{Bind Time}	_0.73s	_0.73s	_~	_~	_~	_{p=1.000 n=6}
_{Check Time}	_{9.80s (± 0.27%)}	_{9.85s (± 0.31%)}	_~	_9.81s	_9.88s	_{p=0.053 n=6}
_{Emit Time}	_{2.73s (± 0.49%)}	_{2.74s (± 0.71%)}	_~	_2.71s	_2.77s	_{p=0.285 n=6}
_{Total Time}	_{14.57s (± 0.17%)}	_{14.62s (± 0.23%)}	_{+0.05s (+ 0.38%)}	_14.57s	_14.66s	_{p=0.024 n=6}
_{angular-1 - node (v18.15.0, x64)}
_Errors	₃₇	₃₇	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_947,969	_947,969	_~	_~	_~	_{p=1.000 n=6}
_Types	_410,955	_410,955	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{1,225,674k (± 0.00%)}	_{1,226,786k (± 0.00%)}	_{+1,113k (+ 0.09%)}	_1,226,726k	_1,226,828k	_{p=0.005 n=6}
_{Parse Time}	_{6.65s (± 0.91%)}	_{6.59s (± 0.50%)}	_~	_6.56s	_6.65s	_{p=0.106 n=6}
_{Bind Time}	_{1.90s (± 0.54%)}	_{1.91s (± 0.29%)}	_~	_1.90s	_1.91s	_{p=0.138 n=6}
_{Check Time}	_{32.07s (± 0.38%)}	_{32.07s (± 0.34%)}	_~	_31.94s	_32.19s	_{p=1.000 n=6}
_{Emit Time}	_{15.23s (± 0.35%)}	_{15.14s (± 0.54%)}	_{-0.10s (- 0.63%)}	_14.98s	_15.22s	_{p=0.016 n=6}
_{Total Time}	_{55.85s (± 0.33%)}	_{55.70s (± 0.27%)}	_~	_55.47s	_55.86s	_{p=0.199 n=6}
_{mui-docs - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,445,991	_2,446,011	_{+20 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_896,571	_896,574	_{+3 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,309,673k (± 0.00%)}	_{2,309,777k (± 0.00%)}	_{+104k (+ 0.00%)}	_2,309,700k	_2,309,818k	_{p=0.008 n=6}
_{Parse Time}	_{8.91s (± 0.27%)}	_{8.94s (± 0.41%)}	_~	_8.90s	_8.99s	_{p=0.361 n=6}
_{Bind Time}	_{2.13s (± 0.49%)}	_{2.12s (± 0.76%)}	_~	_2.10s	_2.14s	_{p=0.510 n=6}
_{Check Time}	_{73.24s (± 0.36%)}	_{73.39s (± 0.49%)}	_~	_72.87s	_73.95s	_{p=0.575 n=6}
_{Emit Time}	_{0.28s (± 2.88%)}	_{0.28s (± 3.19%)}	_~	_0.27s	_0.29s	_{p=0.550 n=6}
_{Total Time}	_{84.55s (± 0.32%)}	_{84.73s (± 0.43%)}	_~	_84.21s	_85.30s	_{p=0.521 n=6}
_{self-build-src - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,228,377	_1,228,452	_{+75 (+ 0.01%)}	_~	_~	_{p=0.001 n=6}
_Types	_266,839	_266,850	_{+11 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,359,941k (± 0.02%)}	_{2,360,079k (± 0.02%)}	_~	_2,359,325k	_2,360,876k	_{p=0.575 n=6}
_{Parse Time}	_{5.17s (± 0.59%)}	_{5.21s (± 1.15%)}	_~	_5.14s	_5.30s	_{p=0.470 n=6}
_{Bind Time}	_{1.77s (± 1.11%)}	_{1.78s (± 1.48%)}	_~	_1.75s	_1.82s	_{p=0.870 n=6}
_{Check Time}	_{35.17s (± 0.22%)}	_{35.34s (± 0.33%)}	_{+0.17s (+ 0.48%)}	_35.21s	_35.54s	_{p=0.020 n=6}
_{Emit Time}	_{2.99s (± 1.77%)}	_{2.99s (± 0.98%)}	_~	_2.96s	_3.04s	_{p=0.936 n=6}
_{Total Time}	_{45.12s (± 0.27%)}	_{45.32s (± 0.29%)}	_{+0.20s (+ 0.44%)}	_45.18s	_45.49s	_{p=0.031 n=6}
_{self-build-src-public-api - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,228,377	_1,228,452	_{+75 (+ 0.01%)}	_~	_~	_{p=0.001 n=6}
_Types	_266,839	_266,850	_{+11 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{3,035,607k (± 9.76%)}	_{3,036,343k (± 9.75%)}	_~	_2,431,398k	_3,158,150k	_{p=0.173 n=6}
_{Parse Time}	_{6.95s (± 1.64%)}	_{7.01s (± 0.77%)}	_~	_6.95s	_7.07s	_{p=0.689 n=6}
_{Bind Time}	_{2.14s (± 2.16%)}	_{2.11s (± 1.10%)}	_~	_2.08s	_2.14s	_{p=0.521 n=6}
_{Check Time}	_{42.90s (± 0.52%)}	_{42.96s (± 0.19%)}	_~	_42.85s	_43.09s	_{p=0.470 n=6}
_{Emit Time}	_{3.50s (± 1.53%)}	_{3.48s (± 1.83%)}	_~	_3.41s	_3.58s	_{p=0.689 n=6}
_{Total Time}	_{55.48s (± 0.59%)}	_{55.57s (± 0.24%)}	_~	_55.43s	_55.73s	_{p=1.000 n=6}
_{self-compiler - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_262,624	_262,697	_{+73 (+ 0.03%)}	_~	_~	_{p=0.001 n=6}
_Types	_106,695	_106,706	_{+11 (+ 0.01%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{440,803k (± 0.02%)}	_{440,842k (± 0.01%)}	_~	_440,755k	_440,886k	_{p=0.689 n=6}
_{Parse Time}	_{3.54s (± 0.46%)}	_{3.56s (± 0.72%)}	_~	_3.53s	_3.60s	_{p=0.222 n=6}
_{Bind Time}	_{1.33s (± 0.56%)}	_{1.33s (± 0.48%)}	_~	_1.32s	_1.34s	_{p=0.718 n=6}
_{Check Time}	_{19.01s (± 0.29%)}	_{19.14s (± 0.39%)}	_{+0.13s (+ 0.69%)}	_19.01s	_19.22s	_{p=0.029 n=6}
_{Emit Time}	_{1.54s (± 1.09%)}	_{1.54s (± 0.86%)}	_~	_1.52s	_1.55s	_{p=0.869 n=6}
_{Total Time}	_{25.43s (± 0.18%)}	_{25.58s (± 0.26%)}	_{+0.15s (+ 0.59%)}	_25.46s	_25.65s	_{p=0.013 n=6}
_{ts-pre-modules - node (v18.15.0, x64)}
_Errors	₇₀	₇₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_226,095	_226,095	_~	_~	_~	_{p=1.000 n=6}
_Types	_94,488	_94,488	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{371,672k (± 0.01%)}	_{371,748k (± 0.04%)}	_~	_371,649k	_372,046k	_{p=0.575 n=6}
_{Parse Time}	_{2.90s (± 1.19%)}	_{2.91s (± 0.68%)}	_~	_2.87s	_2.92s	_{p=0.627 n=6}
_{Bind Time}	_{1.60s (± 1.21%)}	_{1.61s (± 1.07%)}	_~	_1.58s	_1.63s	_{p=0.254 n=6}
_{Check Time}	_{16.46s (± 0.15%)}	_{16.54s (± 0.44%)}	_~	_16.40s	_16.60s	_{p=0.065 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{20.96s (± 0.21%)}	_{21.05s (± 0.38%)}	_{+0.10s (+ 0.46%)}	_20.91s	_21.13s	_{p=0.045 n=6}
_{vscode - node (v18.15.0, x64)}
_Errors	₃	₃	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_3,239,020	_3,239,020	_~	_~	_~	_{p=1.000 n=6}
_Types	_1,115,422	_1,115,422	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{3,306,754k (± 0.01%)}	_{3,306,672k (± 0.00%)}	_~	_3,306,418k	_3,306,810k	_{p=0.378 n=6}
_{Parse Time}	_{14.19s (± 0.76%)}	_{14.19s (± 0.59%)}	_~	_14.09s	_14.31s	_{p=0.936 n=6}
_{Bind Time}	_{4.64s (± 2.81%)}	_{4.55s (± 0.26%)}	_~	_4.54s	_4.57s	_{p=0.139 n=6}
_{Check Time}	_{87.97s (± 1.58%)}	_{87.92s (± 1.34%)}	_~	_86.91s	_90.22s	_{p=0.810 n=6}
_{Emit Time}	_{27.89s (± 2.05%)}	_{28.00s (± 2.82%)}	_~	_27.39s	_29.57s	_{p=0.873 n=6}
_{Total Time}	_{134.69s (± 1.15%)}	_{134.66s (± 1.03%)}	_~	_133.15s	_136.65s	_{p=0.575 n=6}
_{webpack - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_291,595	_291,595	_~	_~	_~	_{p=1.000 n=6}
_Types	_118,971	_118,971	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{445,342k (± 0.02%)}	_{445,322k (± 0.03%)}	_~	_445,142k	_445,518k	_{p=0.936 n=6}
_{Parse Time}	_{5.08s (± 1.17%)}	_{5.10s (± 0.63%)}	_~	_5.05s	_5.15s	_{p=0.333 n=6}
_{Bind Time}	_{2.22s (± 0.66%)}	_{2.20s (± 1.28%)}	_~	_2.15s	_2.23s	_{p=0.145 n=6}
_{Check Time}	_{23.36s (± 0.46%)}	_{23.61s (± 2.24%)}	_~	_23.23s	_24.67s	_{p=0.261 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{30.66s (± 0.26%)}	_{30.92s (± 1.67%)}	_~	_30.59s	_31.95s	_{p=0.378 n=6}
_{xstate-main - node (v18.15.0, x64)}
_Errors	₅	₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_555,050	_555,112	_{+62 (+ 0.01%)}	_~	_~	_{p=0.001 n=6}
_Types	_186,115	_186,131	_{+16 (+ 0.01%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{494,021k (± 0.01%)}	_{494,102k (± 0.01%)}	_~	_494,030k	_494,206k	_{p=0.066 n=6}
_{Parse Time}	_{3.40s (± 0.86%)}	_{3.42s (± 0.48%)}	_~	_3.39s	_3.44s	_{p=0.224 n=6}
_{Bind Time}	_{1.19s (± 0.92%)}	_{1.19s (± 1.37%)}	_~	_1.16s	_1.21s	_{p=0.931 n=6}
_{Check Time}	_{19.55s (± 0.24%)}	_{19.66s (± 0.46%)}	_{+0.11s (+ 0.55%)}	_19.52s	_19.77s	_{p=0.045 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{24.15s (± 0.25%)}	_{24.26s (± 0.40%)}	_{+0.12s (+ 0.48%)}	_24.10s	_24.36s	_{p=0.045 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:

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typescript-bot · 2025-01-13T22:38:03Z

@jakebailey Here are the results of running the top 400 repos with tsc comparing main and refs/pull/60868/merge:

Everything looks good!

typescript-bot added the For Uncommitted Bug PR for untriaged, rejected, closed or missing bug label Dec 29, 2024

MichaelMitchell-at mentioned this pull request Dec 29, 2024

Merge trivially mergeable intersection types for identity comparison #60726

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Make identity comparison reflexive across unions or intersections of …

7b7a9b2

…the same type

MichaelMitchell-at force-pushed the reflexive_identity_comparisons branch from 70d3914 to 7b7a9b2 Compare December 29, 2024 08:06

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Make identity comparison reflexive across unions or intersections of the same type #60868

Make identity comparison reflexive across unions or intersections of the same type #60868

MichaelMitchell-at commented Dec 29, 2024

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tsc

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Make identity comparison reflexive across unions or intersections of the same type #60868

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Make identity comparison reflexive across unions or intersections of the same type #60868

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tsc

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