Narrow destructured variables based on initializer's analysis result by nekolab · Pull Request #59745 · microsoft/TypeScript

nekolab · 2024-08-25T06:24:08Z

This PR introduces a method to narrow the types of destructured variables through control flow analysis without relying on the discriminant member.

When the initializer of the ObjectBindingPattern is available, we attempt to narrow its type, which in turn helps further refine the type of the destructured variable.

Partially fixes #59657

This PR introduces a method to narrow the types of destructured variables through control flow analysis without relying on the discriminant member. When the initializer of the `ObjectBindingPattern` is available, we attempt to narrow its type, which in turn helps further refine the type of the destructured variable. Partially fixes microsoft#59657

nekolab · 2024-08-25T06:26:45Z

@microsoft-github-policy-service agree

RyanCavanaugh · 2025-12-05T05:23:23Z

@typescript-bot test it

typescript-bot · 2025-12-05T05:23:27Z

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 · 2025-12-05T05:44:34Z

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

Everything looks the same!

You can check the log here.

typescript-bot · 2025-12-05T05:52:14Z

@RyanCavanaugh Here are the results of running the user tests with tsc comparing main and refs/pull/59745/merge:

There were infrastructure failures potentially unrelated to your change:

1 instance of "Git clone failed"

Otherwise...

Everything looks good!

typescript-bot · 2025-12-05T06:17:08Z

@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	₁	₁	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_62,370	_62,370	_~	_~	_~	_{p=1.000 n=6}
_Types	_50,387	_50,387	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{193,332k (± 0.75%)}	_{194,426k (± 1.00%)}	_~	_192,622k	_196,230k	_{p=0.810 n=6}
_{Parse Time}	_{1.31s (± 0.39%)}	_{1.30s (± 0.63%)}	_{-0.01s (- 0.77%)}	_1.29s	_1.31s	_{p=0.050 n=6}
_{Bind Time}	_0.75s	_0.75s	_~	_~	_~	_{p=1.000 n=6}
_{Check Time}	_{9.89s (± 0.41%)}	_{9.90s (± 0.25%)}	_~	_9.85s	_9.92s	_{p=0.466 n=6}
_{Emit Time}	_{2.73s (± 0.71%)}	_{2.74s (± 0.72%)}	_~	_2.71s	_2.77s	_{p=0.118 n=6}
_{Total Time}	_{14.67s (± 0.30%)}	_{14.69s (± 0.13%)}	_~	_14.66s	_14.71s	_{p=0.747 n=6}
_{angular-1 - node (v18.15.0, x64)}
_Errors	₂	₂	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_956,048	_956,048	_~	_~	_~	_{p=1.000 n=6}
_Types	_415,904	_415,904	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{1,255,024k (± 0.00%)}	_{1,255,049k (± 0.00%)}	_~	_1,255,028k	_1,255,081k	_{p=0.230 n=6}
_{Parse Time}	_{6.53s (± 0.82%)}	_{6.55s (± 0.46%)}	_~	_6.50s	_6.58s	_{p=0.686 n=6}
_{Bind Time}	_{1.96s (± 0.42%)}	_{1.96s (± 0.26%)}	_~	_1.96s	_1.97s	_{p=0.114 n=6}
_{Check Time}	_{32.40s (± 0.42%)}	_{32.37s (± 0.28%)}	_~	_32.19s	_32.43s	_{p=0.936 n=6}
_{Emit Time}	_{14.89s (± 0.41%)}	_{14.84s (± 0.48%)}	_~	_14.71s	_14.93s	_{p=0.172 n=6}
_{Total Time}	_{55.77s (± 0.30%)}	_{55.72s (± 0.17%)}	_~	_55.58s	_55.81s	_{p=0.630 n=6}
_{mui-docs - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,722,102	_2,722,102	_~	_~	_~	_{p=1.000 n=6}
_Types	_937,520	_937,520	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{3,050,975k (± 0.00%)}	_{3,050,958k (± 0.00%)}	_~	_3,050,887k	_3,051,058k	_{p=0.810 n=6}
_{Parse Time}	_{8.55s (± 0.23%)}	_{8.54s (± 0.20%)}	_~	_8.52s	_8.56s	_{p=0.408 n=6}
_{Bind Time}	_{2.33s (± 0.53%)}	_{2.32s (± 0.52%)}	_~	_2.30s	_2.33s	_{p=0.271 n=6}
_{Check Time}	_{93.03s (± 0.45%)}	_{93.07s (± 0.35%)}	_~	_92.76s	_93.58s	_{p=0.689 n=6}
_{Emit Time}	_{0.31s (± 2.04%)}	_{0.31s (± 1.31%)}	_~	_0.31s	_0.32s	_{p=0.673 n=6}
_{Total Time}	_{104.22s (± 0.40%)}	_{104.24s (± 0.31%)}	_~	_103.93s	_104.73s	_{p=0.748 n=6}
_{self-build-src - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,251,654	_1,251,655	_{+1 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_259,840	_259,840	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,514,514k (± 7.45%)}	_{2,392,739k (± 0.02%)}	_{🟩-121,775k (- 4.84%)}	_2,392,066k	_2,393,086k	_{p=0.031 n=6}
_{Parse Time}	_{5.14s (± 0.86%)}	_{5.12s (± 0.60%)}	_~	_5.07s	_5.14s	_{p=0.378 n=6}
_{Bind Time}	_{1.81s (± 0.95%)}	_{1.83s (± 2.05%)}	_~	_1.80s	_1.90s	_{p=0.260 n=6}
_{Check Time}	_{35.33s (± 0.80%)}	_{35.55s (± 0.15%)}	_~	_35.49s	_35.63s	_{p=0.109 n=6}
_{Emit Time}	_{3.00s (± 1.77%)}	_{3.03s (± 1.15%)}	_~	_3.00s	_3.09s	_{p=0.518 n=6}
_{Total Time}	_{45.29s (± 0.63%)}	_{45.55s (± 0.14%)}	_~	_45.50s	_45.68s	_{p=0.173 n=6}
_{self-build-src-public-api - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,251,654	_1,251,655	_{+1 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_259,840	_259,840	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{3,188,612k (± 0.02%)}	_{3,094,218k (± 7.49%)}	_~	_2,620,730k	_3,189,413k	_{p=0.810 n=6}
_{Parse Time}	_{6.75s (± 1.16%)}	_{6.73s (± 0.86%)}	_~	_6.64s	_6.79s	_{p=0.748 n=6}
_{Bind Time}	_{2.26s (± 1.34%)}	_{2.26s (± 1.18%)}	_~	_2.21s	_2.29s	_{p=1.000 n=6}
_{Check Time}	_{43.03s (± 0.14%)}	_{42.90s (± 1.09%)}	_~	_41.99s	_43.30s	_{p=0.688 n=6}
_{Emit Time}	_{3.53s (± 1.79%)}	_{3.46s (± 1.41%)}	_~	_3.41s	_3.52s	_{p=0.077 n=6}
_{Total Time}	_{55.58s (± 0.12%)}	_{55.33s (± 0.84%)}	_~	_54.42s	_55.67s	_{p=0.298 n=6}
_{self-compiler - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_264,287	_264,288	_{+1 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_104,051	_104,051	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{443,352k (± 0.02%)}	_{443,311k (± 0.01%)}	_~	_443,245k	_443,394k	_{p=0.470 n=6}
_{Parse Time}	_{3.52s (± 0.62%)}	_{3.53s (± 0.66%)}	_~	_3.49s	_3.56s	_{p=0.567 n=6}
_{Bind Time}	_{1.39s (± 1.06%)}	_{1.37s (± 1.57%)}	_~	_1.34s	_1.40s	_{p=0.145 n=6}
_{Check Time}	_{19.22s (± 0.35%)}	_{19.27s (± 0.42%)}	_~	_19.17s	_19.37s	_{p=0.332 n=6}
_{Emit Time}	_{1.55s (± 0.63%)}	_{1.55s (± 0.89%)}	_~	_1.52s	_1.56s	_{p=0.720 n=6}
_{Total Time}	_{25.68s (± 0.34%)}	_{25.71s (± 0.36%)}	_~	_25.61s	_25.85s	_{p=0.688 n=6}
_{ts-pre-modules - node (v18.15.0, x64)}
_Errors	₇₂	₇₂	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_225,493	_225,493	_~	_~	_~	_{p=1.000 n=6}
_Types	_94,373	_94,373	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{370,210k (± 0.07%)}	_{370,141k (± 0.01%)}	_~	_370,082k	_370,220k	_{p=0.630 n=6}
_{Parse Time}	_{2.83s (± 1.06%)}	_{2.83s (± 0.97%)}	_~	_2.79s	_2.85s	_{p=0.870 n=6}
_{Bind Time}	_{1.64s (± 1.14%)}	_{1.64s (± 0.86%)}	_~	_1.62s	_1.66s	_{p=0.805 n=6}
_{Check Time}	_{16.64s (± 0.44%)}	_{16.64s (± 0.28%)}	_~	_16.58s	_16.69s	_{p=1.000 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{21.11s (± 0.43%)}	_{21.11s (± 0.16%)}	_~	_21.05s	_21.14s	_{p=0.810 n=6}
_{vscode - node (v18.15.0, x64)}
_Errors	₁₁	₁₁	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_4,079,846	_4,079,847	_{+1 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_1,285,484	_1,285,484	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{3,865,525k (± 0.00%)}	_{3,865,433k (± 0.00%)}	_~	_3,865,282k	_3,865,521k	_{p=0.092 n=6}
_{Parse Time}	_{15.72s (± 0.67%)}	_{15.70s (± 0.69%)}	_~	_15.56s	_15.86s	_{p=0.748 n=6}
_{Bind Time}	_{5.30s (± 0.58%)}	_{5.36s (± 2.20%)}	_~	_5.27s	_5.57s	_{p=0.518 n=6}
_{Check Time}	_{113.30s (± 1.49%)}	_{112.74s (± 2.48%)}	_~	_109.22s	_117.51s	_{p=0.689 n=6}
_{Emit Time}	_{40.37s (± 7.56%)}	_{42.86s (±15.26%)}	_~	_38.89s	_54.98s	_{p=1.000 n=6}
_{Total Time}	_{174.69s (± 1.38%)}	_{176.66s (± 2.96%)}	_~	_171.72s	_185.18s	_{p=0.689 n=6}
_{webpack - node (v18.15.0, x64)}
_Errors	₄₀	₄₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_380,758	_380,758	_~	_~	_~	_{p=1.000 n=6}
_Types	_166,811	_166,811	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{540,877k (± 0.01%)}	_{540,911k (± 0.03%)}	_~	_540,728k	_541,205k	_{p=1.000 n=6}
_{Parse Time}	_{4.73s (± 0.76%)}	_{4.71s (± 0.39%)}	_~	_4.69s	_4.74s	_{p=0.466 n=6}
_{Bind Time}	_{2.02s (± 1.58%)}	_{2.04s (± 1.41%)}	_~	_2.00s	_2.07s	_{p=0.687 n=6}
_{Check Time}	_{23.01s (± 0.47%)}	_{22.96s (± 0.44%)}	_~	_22.85s	_23.12s	_{p=0.574 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{29.76s (± 0.48%)}	_{29.71s (± 0.40%)}	_~	_29.59s	_29.91s	_{p=0.575 n=6}
_{xstate-main - node (v18.15.0, x64)}
_Errors	₃₀	₃₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_692,951	_692,951	_~	_~	_~	_{p=1.000 n=6}
_Types	_210,425	_210,425	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{588,884k (± 0.02%)}	_{588,954k (± 0.02%)}	_~	_588,791k	_589,117k	_{p=0.298 n=6}
_{Parse Time}	_{4.18s (± 0.58%)}	_{4.18s (± 0.40%)}	_~	_4.17s	_4.21s	_{p=0.803 n=6}
_{Bind Time}	_{1.41s (± 0.83%)}	_{1.42s (± 0.73%)}	_~	_1.40s	_1.43s	_{p=0.241 n=6}
_{Check Time}	_{21.23s (± 1.72%)}	_{21.13s (± 1.73%)}	_~	_20.75s	_21.57s	_{p=0.936 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{26.81s (± 1.30%)}	_{26.73s (± 1.43%)}	_~	_26.33s	_27.19s	_{p=1.000 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 · 2025-12-05T06:47:03Z

@RyanCavanaugh Here are the results of running the top 400 repos with tsc comparing main and refs/pull/59745/merge:

Everything looks good!

nekolab · 2026-01-20T09:08:43Z

Hi @RyanCavanaugh, just a friendly ping if you have time to review this PR, as we got all green from the bot

typescript-bot added the For Backlog Bug PRs that fix a backlog bug label Aug 25, 2024

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Narrow destructured variables based on initializer's analysis result#59745

Narrow destructured variables based on initializer's analysis result#59745
nekolab wants to merge 1 commit intomicrosoft:mainfrom
nekolab:fix59657

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