fix(65069): preserve contextual types for array-destructured parameter defaults by timurzvural · Pull Request #65070 · microsoft/TypeScript

Timur Vural (timurzvural) · 2026-10-31T01:01:35Z

Bug

In 7.1, a destructured parameter with a default like = [] loses its contextual type and reports TS7031 on binding elements. The object form (= {}) is #64974; this PR covers the array form and also guards object padding the same way.

type F = (input?: [string?, number?]) => number;
export const f: F = ([a, b] = []) => (a ? 1 : 0) + (b ?? 0);

Fix

In checkDeclarationInitializer, only call padTupleType / padObjectLiteralType when getContextualTypeForVariableLikeDeclaration(root, ContextFlagsNone) == nil. Padding invents any-typed missing elements and must not override a contextual parameter type.

Tests

Extended objectBindingPatternDefaultMissingElements.ts (and baselines) with array/= [] cases from #65069 and an object/= {} case.

Fixes 7.1: array-destructured parameter with a = [] default loses its contextual type (TS7031) #65069
Also covers the object side of 7.1: destructured parameter with a = {} default loses its contextual type (TS7031) #64974 (open fix(64974): fix contextual typing for destructured parameter defaults #64978 only guards objects today)
Overlaps with fix(65011): preserve contextual types for destructured parameter defaults #65016

AI assistance disclosure

This PR was authored with assistance from Cursor Agent. I have read and understand the change and am prepared to discuss and revise it in review.

…r defaults Skip padTupleType when the parameter already has a contextual type, matching the object-pattern guard for microsoft#64974. Also apply the same guard to padObjectLiteralType so object `= {}` defaults keep working on the same path. Co-authored-by: Cursor <cursoragent@cursor.com>

Copilot

🟢 Approval recommended

The change preserving contextual types in destructured parameter defaults has no active review issues.

No open issues 🎉

What changed in this PR

Fixes #65069 by preserving contextual types for array-destructured parameter defaults in the native TypeScript checker. The same guard also addresses object defaults from #64974.

Changes:

Skip tuple and object padding when the parameter has a contextual type.
Add regression cases for object defaults, array defaults, callbacks, and nested/rest destructuring.
Update type, symbol, and diagnostic baselines.

File	Description
`tsc/testdata/tests/cases/compiler/objectBindingPatternDefaultMissingElements.ts`	Adds contextual-typing regression cases.
`tsc/testdata/baselines/reference/compiler/objectBindingPatternDefaultMissingElements.types`	Records preserved binding-element types.
`tsc/testdata/baselines/reference/compiler/objectBindingPatternDefaultMissingElements.symbols`	Records symbols for the added cases.
`tsc/testdata/baselines/reference/compiler/objectBindingPatternDefaultMissingElements.errors.txt`	Records expected assignment errors that verify contextual typing.
`tsc/internal/checker/checker.go`	Guards object and tuple padding with a contextual-type check.

_{Review effort: Balanced}

Ryan Cavanaugh (RyanCavanaugh) · 2026-11-03T00:21:30Z

TypeScript Bot (@typescript-bot) test it

typescript-automation · 2026-11-03T00:21:38Z

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-automation · 2026-11-03T00:53:16Z

Hey Ryan Cavanaugh (@RyanCavanaugh), the results of running the DT tests are ready.

Everything looks the same!

You can check the log here.

typescript-automation · 2026-11-03T00:59:38Z

Ryan Cavanaugh (@RyanCavanaugh) Here are the results of running the user tests with tsc comparing baseline and pr:

Everything looks good!

typescript-automation · 2026-11-03T01:12:48Z

Ryan Cavanaugh (@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 - native}
_Errors	₄₁	₄₁	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_88,466	_88,466	_~	_~	_~	_{p=1.000 n=20}
_Types	_79,607	_79,607	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{107,473k (± 0.03%)}	_{107,510k (± 0.03%)}	_~	_107,351k	_107,645k	_{p=0.151 n=20}
_{Memory Allocs}	_{1,262,365 (± 0.01%)}	_{1,262,345 (± 0.01%)}	_~	_1,261,903	_1,262,601	_{p=0.784 n=20}
_{Config Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.022s (± 2.98%)}	_{0.022s (± 3.18%)}	_~	_0.019s	_0.024s	_{p=0.873 n=20}
_{Bind Time}	_{0.008s (± 5.21%)}	_{0.008s (± 5.81%)}	_~	_0.007s	_0.010s	_{p=0.768 n=20}
_{Check Time}	_{0.210s (± 0.65%)}	_{0.210s (± 0.65%)}	_~	_0.204s	_0.214s	_{p=0.856 n=20}
_{Emit Time}	_{0.132s (± 1.23%)}	_{0.132s (± 1.09%)}	_~	_0.128s	_0.140s	_{p=0.845 n=20}
_{Total Time}	_{0.376s (± 0.36%)}	_{0.376s (± 0.42%)}	_~	_0.370s	_0.384s	_{p=0.671 n=20}
_{angular-1 - native}
_Errors	₃	₃	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_586,553	_586,553	_~	_~	_~	_{p=1.000 n=20}
_Types	_241,682	_241,682	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{519,768k (± 0.02%)}	_{519,800k (± 0.01%)}	_~	_519,359k	_520,047k	_{p=0.289 n=20}
_{Memory Allocs}	_{7,800,419 (± 0.16%)}	_{7,793,467 (± 0.10%)}	_~	_7,780,410	_7,833,320	_{p=0.289 n=20}
_{Config Time}	_{0.008s (± 2.64%)}	_{0.008s (± 2.51%)}	_~	_0.008s	_0.009s	_{p=1.000 n=20}
_{Parse Time}	_{0.125s (± 5.46%)}	_{0.126s (± 4.35%)}	_~	_0.117s	_0.158s	_{p=0.422 n=20}
_{Bind Time}	_{0.047s (±11.45%)}	_{0.039s (± 7.53%)}	_~	_0.035s	_0.059s	_{p=0.090 n=20}
_{Check Time}	_0s	_0s	_~	_~	_~	_{p=1.000 n=20}
_{Emit Time}	_{0.627s (± 0.72%)}	_{0.625s (± 0.58%)}	_~	_0.616s	_0.647s	_{p=0.489 n=20}
_{Total Time}	_{0.822s (± 0.77%)}	_{0.808s (± 0.92%)}	_{-0.014s (- 1.67%)}	_0.789s	_0.844s	_{p=0.005 n=20}
_{arktype - native}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_685,920	_685,920	_~	_~	_~	_{p=1.000 n=20}
_Types	_939,467	_939,467	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{495,316k (± 0.01%)}	_{495,331k (± 0.01%)}	_~	_495,197k	_495,546k	_{p=0.351 n=20}
_{Memory Allocs}	_{12,064,148 (± 0.02%)}	_{12,063,726 (± 0.02%)}	_~	_12,059,430	_12,072,416	_{p=0.507 n=20}
_{Config Time}	_0.001s	_0.001s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.042s (± 4.56%)}	_{0.042s (± 4.15%)}	_~	_0.037s	_0.055s	_{p=0.867 n=20}
_{Bind Time}	_{0.013s (± 9.67%)}	_{0.014s (±10.26%)}	_~	_0.011s	_0.020s	_{p=0.347 n=20}
_{Check Time}	_{0.885s (± 0.71%)}	_{0.877s (± 0.68%)}	_~	_0.859s	_0.896s	_{p=0.113 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{0.967s (± 0.70%)}	_{0.962s (± 0.57%)}	_~	_0.945s	_0.989s	_{p=0.260 n=20}
_{class-transformer - native}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_45,376	_45,376	_~	_~	_~	_{p=1.000 n=20}
_Types	_7,573	_7,573	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{27,894k (± 0.03%)}	_{27,889k (± 0.03%)}	_~	_27,862k	_27,917k	_{p=0.516 n=20}
_{Memory Allocs}	_{248,323 (± 0.06%)}	_{248,297 (± 0.05%)}	_~	_247,953	_248,919	_{p=0.794 n=20}
_{Config Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.011s (± 3.61%)}	_{0.011s (± 3.08%)}	_~	_0.009s	_0.012s	_{p=1.000 n=20}
_{Bind Time}	_{0.003s (±11.33%)}	_{0.003s (±11.26%)}	_~	_0.002s	_0.005s	_{p=0.644 n=20}
_{Check Time}	_{0.008s (± 5.24%)}	_{0.008s (± 7.21%)}	_~	_0.006s	_0.010s	_{p=0.791 n=20}
_{Emit Time}	_{0.007s (± 8.32%)}	_{0.008s (± 7.94%)}	_~	_0.006s	_0.010s	_{p=0.515 n=20}
_{Total Time}	_{0.031s (± 2.15%)}	_{0.031s (± 2.04%)}	_~	_0.027s	_0.033s	_{p=0.677 n=20}
_{effect - native}
_Errors	₁₂	₁₂	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_1,235,115	_1,235,115	_~	_~	_~	_{p=1.000 n=20}
_Types	_894,113	_894,113	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{949,958k (± 0.02%)}	_{949,897k (± 0.02%)}	_~	_949,037k	_951,152k	_{p=0.410 n=20}
_{Memory Allocs}	_{12,640,064 (± 0.03%)}	_{12,639,229 (± 0.03%)}	_~	_12,631,905	_12,658,449	_{p=0.904 n=20}
_{Config Time}	_0.002s	_0.002s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.149s (± 2.54%)}	_{0.146s (± 1.95%)}	_~	_0.137s	_0.162s	_{p=0.213 n=20}
_{Bind Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Check Time}	_{0.876s (± 0.97%)}	_{0.867s (± 1.01%)}	_~	_0.842s	_0.902s	_{p=0.167 n=20}
_{Emit Time}	_{0.475s (± 1.54%)}	_{0.482s (± 1.51%)}	_~	_0.449s	_0.508s	_{p=0.239 n=20}
_{Total Time}	_{1.589s (± 0.56%)}	_{1.589s (± 0.56%)}	_~	_1.558s	_1.618s	_{p=0.984 n=20}
_{mui-docs - native}
_Errors	_11,405	_11,405	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_3,784,019	_3,784,019	_~	_~	_~	_{p=1.000 n=20}
_Types	_1,355,974	_1,355,974	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{1,766,888k (± 0.06%)}	_{1,768,703k (± 0.07%)}	_{+1,815k (+ 0.10%)}	_1,763,372k	_1,774,544k	_{p=0.033 n=20}
_{Memory Allocs}	_{25,724,473 (± 0.16%)}	_{25,750,288 (± 0.14%)}	_~	_25,646,211	_25,947,706	_{p=0.242 n=20}
_{Config Time}	_{0.009s (± 2.37%)}	_{0.009s (± 6.03%)}	_~	_0.008s	_0.014s	_{p=0.264 n=20}
_{Parse Time}	_{0.310s (± 3.45%)}	_{0.309s (± 4.34%)}	_~	_0.270s	_0.371s	_{p=0.723 n=20}
_{Bind Time}	_{0.001s (± 9.93%)}	_0.001s	_~	_~	_~	_{p=1.000 n=20}
_{Check Time}	_{3.192s (± 1.94%)}	_{3.226s (± 2.00%)}	_~	_3.085s	_3.521s	_{p=0.298 n=20}
_{Emit Time}	_{0.266s (± 3.20%)}	_{0.263s (± 1.87%)}	_~	_0.247s	_0.286s	_{p=0.857 n=20}
_{Total Time}	_{4.304s (± 1.85%)}	_{4.351s (± 1.98%)}	_~	_4.159s	_4.760s	_{p=0.387 n=20}
_{sentry - native}
_Errors	₂	₁	_{🟩-1 (-50.00%)}	_~	_~	_{p=0.000 n=20}
_Symbols	_4,793,245	_4,793,244	_{-1 (- 0.00%)}	_~	_~	_{p=0.000 n=20}
_Types	_2,606,905	_2,606,901	_{-4 (- 0.00%)}	_~	_~	_{p=0.000 n=20}
_{Memory Used}	_{2,845,946k (± 0.02%)}	_{2,846,137k (± 0.02%)}	_~	_2,844,266k	_2,848,417k	_{p=0.645 n=20}
_{Memory Allocs}	_{75,262,190 (± 0.27%)}	_{75,188,811 (± 0.30%)}	_~	_74,631,881	_76,367,991	_{p=0.547 n=20}
_{Config Time}	_{0.026s (± 0.93%)}	_{0.026s (± 0.80%)}	_~	_0.026s	_0.028s	_{p=0.605 n=20}
_{Parse Time}	_{0.502s (± 3.51%)}	_{0.509s (± 3.75%)}	_~	_0.452s	_0.624s	_{p=0.794 n=20}
_{Bind Time}	_{0.169s (±11.67%)}	_{0.147s (± 7.93%)}	_~	_0.124s	_0.212s	_{p=0.109 n=20}
_{Check Time}	_{7.012s (± 0.75%)}	_{7.004s (± 0.83%)}	_~	_6.808s	_7.176s	_{p=0.857 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{7.765s (± 0.81%)}	_{7.739s (± 0.93%)}	_~	_7.495s	_8.011s	_{p=0.560 n=20}
_{social-app - native}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_1,883,074	_1,883,060	_{-14 (- 0.00%)}	_~	_~	_{p=0.000 n=20}
_Types	_1,158,168	_1,158,160	_{-8 (- 0.00%)}	_~	_~	_{p=0.000 n=20}
_{Memory Used}	_{967,056k (± 0.01%)}	_{966,910k (± 0.02%)}	_~	_966,352k	_968,092k	_{p=0.108 n=20}
_{Memory Allocs}	_{13,489,513 (± 0.12%)}	_{13,518,975 (± 0.27%)}	_~	_13,439,483	_13,739,954	_{p=0.231 n=20}
_{Config Time}	_{0.008s (± 3.08%)}	_{0.008s (± 3.08%)}	_~	_0.007s	_0.008s	_{p=1.000 n=20}
_{Parse Time}	_{0.159s (± 3.71%)}	_{0.163s (± 4.06%)}	_~	_0.150s	_0.199s	_{p=0.323 n=20}
_{Bind Time}	_{0.040s (± 7.30%)}	_{0.046s (±14.83%)}	_~	_0.036s	_0.096s	_{p=0.095 n=20}
_{Check Time}	_{1.442s (± 1.19%)}	_{1.432s (± 0.99%)}	_~	_1.399s	_1.504s	_{p=0.358 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{1.666s (± 1.12%)}	_{1.667s (± 0.99%)}	_~	_1.616s	_1.738s	_{p=0.794 n=20}
_{strada-build-src - native}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_1,184,972	_1,184,972	_~	_~	_~	_{p=1.000 n=20}
_Types	_438,959	_438,959	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{1,173,951k (± 0.37%)}	_{1,180,076k (± 0.49%)}	_{+6,125k (+ 0.52%)}	_1,163,598k	_1,218,768k	_{p=0.038 n=20}
_{Memory Allocs}	_{47,632,891 (± 0.14%)}	_{47,658,810 (± 0.12%)}	_~	_47,405,938	_47,876,068	_{p=0.738 n=20}
_{Config Time}	_{0.002s (±23.93%)}	_{0.002s (±24.27%)}	_~	_0.000s	_0.004s	_{p=0.566 n=20}
_{Parse Time}	_{0.150s (± 2.56%)}	_{0.151s (± 1.43%)}	_~	_0.142s	_0.160s	_{p=0.995 n=20}
_{Bind Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Check Time}	_{0.865s (± 1.06%)}	_{0.877s (± 1.11%)}	_{+0.012s (+ 1.36%)}	_0.835s	_0.928s	_{p=0.027 n=20}
_{Emit Time}	_{0.151s (± 2.95%)}	_{0.154s (± 2.51%)}	_~	_0.141s	_0.169s	_{p=0.298 n=20}
_{Total Time}	_{10.089s (± 0.86%)}	_{10.259s (± 1.01%)}	_{+0.170s (+ 1.68%)}	_9.903s	_10.720s	_{p=0.025 n=20}
_{strada-compiler - native}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_263,511	_263,511	_~	_~	_~	_{p=1.000 n=20}
_Types	_196,116	_196,116	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{223,549k (± 0.02%)}	_{223,546k (± 0.02%)}	_~	_223,428k	_223,758k	_{p=0.857 n=20}
_{Memory Allocs}	_{2,390,727 (± 0.01%)}	_{2,390,986 (± 0.01%)}	_~	_2,389,783	_2,392,460	_{p=0.277 n=20}
_{Config Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.050s (± 3.31%)}	_{0.049s (± 3.90%)}	_~	_0.043s	_0.057s	_{p=0.415 n=20}
_{Bind Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Check Time}	_{0.377s (± 1.82%)}	_{0.376s (± 1.67%)}	_~	_0.358s	_0.406s	_{p=0.878 n=20}
_{Emit Time}	_{0.050s (± 4.93%)}	_{0.047s (± 5.59%)}	_~	_0.041s	_0.057s	_{p=0.309 n=20}
_{Total Time}	_{0.504s (± 1.50%)}	_{0.500s (± 1.31%)}	_~	_0.484s	_0.535s	_{p=0.239 n=20}
_{t3code-server - native}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_4,350,661	_4,350,661	_~	_~	_~	_{p=1.000 n=20}
_Types	_3,040,644	_3,040,644	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{2,417,678k (± 0.02%)}	_{2,417,647k (± 0.02%)}	_~	_2,415,917k	_2,419,479k	_{p=0.968 n=20}
_{Memory Allocs}	_{37,165,229 (± 0.08%)}	_{37,166,508 (± 0.08%)}	_~	_37,086,645	_37,330,049	_{p=0.989 n=20}
_{Config Time}	_0.003s	_{0.003s (± 3.54%)}	_~	_0.002s	_0.003s	_{p=1.000 n=20}
_{Parse Time}	_{0.252s (± 2.27%)}	_{0.249s (± 2.36%)}	_~	_0.229s	_0.271s	_{p=0.683 n=20}
_{Bind Time}	_{0.080s (± 6.76%)}	_{0.088s (± 9.90%)}	_~	_0.072s	_0.130s	_{p=0.187 n=20}
_{Check Time}	_{5.746s (± 0.40%)}	_{5.772s (± 0.54%)}	_~	_5.687s	_5.940s	_{p=0.279 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{6.092s (± 0.45%)}	_{6.125s (± 0.58%)}	_~	_6.017s	_6.318s	_{p=0.180 n=20}
_{tanstack-router - native}
_Errors	₁	₁	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_571,756	_571,756	_~	_~	_~	_{p=1.000 n=20}
_Types	_397,689	_397,689	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{326,503k (± 0.02%)}	_{326,501k (± 0.02%)}	_~	_326,293k	_326,722k	_{p=0.920 n=20}
_{Memory Allocs}	_{4,334,484 (± 0.16%)}	_{4,334,903 (± 0.15%)}	_~	_4,319,602	_4,359,954	_{p=0.841 n=20}
_{Config Time}	_0.001s	_0.001s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.039s (± 3.42%)}	_{0.039s (± 2.79%)}	_~	_0.035s	_0.044s	_{p=0.531 n=20}
_{Bind Time}	_{0.012s (± 9.09%)}	_{0.012s (± 8.10%)}	_~	_0.010s	_0.017s	_{p=0.924 n=20}
_{Check Time}	_{0.505s (± 0.65%)}	_{0.510s (± 1.06%)}	_~	_0.492s	_0.531s	_{p=0.285 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{0.576s (± 0.90%)}	_{0.579s (± 1.01%)}	_~	_0.561s	_0.599s	_{p=0.723 n=20}
_{ts-pre-modules - native}
_Errors	₈₇	₈₇	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_231,616	_231,616	_~	_~	_~	_{p=1.000 n=20}
_Types	_181,195	_181,195	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{192,961k (± 0.02%)}	_{192,960k (± 0.02%)}	_~	_192,829k	_193,088k	_{p=0.989 n=20}
_{Memory Allocs}	_{1,311,085 (± 0.02%)}	_{1,311,224 (± 0.02%)}	_~	_1,310,071	_1,313,356	_{p=0.569 n=20}
_{Config Time}	_{0.000s (±208.60%)}	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.048s (± 3.30%)}	_{0.047s (± 3.20%)}	_~	_0.041s	_0.056s	_{p=0.370 n=20}
_{Bind Time}	_{0.022s (± 7.00%)}	_{0.024s (± 7.62%)}	_~	_0.018s	_0.030s	_{p=0.093 n=20}
_{Check Time}	_{0.340s (± 2.97%)}	_{0.342s (± 3.24%)}	_~	_0.309s	_0.383s	_{p=0.920 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{0.416s (± 2.66%)}	_{0.419s (± 2.92%)}	_~	_0.381s	_0.460s	_{p=0.825 n=20}
_{vscode - native}
_Errors	₁₁	₁₁	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_7,636,537	_7,636,537	_~	_~	_~	_{p=1.000 n=20}
_Types	_4,487,680	_4,487,680	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{5,275,537k (± 0.02%)}	_{5,276,938k (± 0.02%)}	_{+1,401k (+ 0.03%)}	_5,272,979k	_5,285,064k	_{p=0.043 n=20}
_{Memory Allocs}	_{57,748,067 (± 0.02%)}	_{57,740,372 (± 0.01%)}	_~	_57,722,607	_57,786,141	_{p=0.183 n=20}
_{Config Time}	_{0.034s (± 1.11%)}	_{0.034s (± 1.27%)}	_~	_0.033s	_0.036s	_{p=0.403 n=20}
_{Parse Time}	_{0.905s (± 1.86%)}	_{0.899s (± 1.17%)}	_~	_0.848s	_0.937s	_{p=0.425 n=20}
_{Bind Time}	_{0.320s (± 6.68%)}	_{0.308s (± 4.15%)}	_~	_0.291s	_0.422s	_{p=0.703 n=20}
_{Check Time}	_{7.905s (± 0.81%)}	_{7.904s (± 0.61%)}	_~	_7.741s	_8.068s	_{p=0.779 n=20}
_{Emit Time}	_{2.024s (± 6.76%)}	_{1.981s (± 5.24%)}	_~	_1.874s	_2.757s	_{p=0.597 n=20}
_{Total Time}	_{11.248s (± 1.14%)}	_{11.186s (± 1.04%)}	_~	_10.935s	_11.911s	_{p=0.365 n=20}
_{webpack - native}
_Errors	₆₁₁	₆₁₁	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_884,750	_884,750	_~	_~	_~	_{p=1.000 n=20}
_Types	_624,363	_624,363	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{651,745k (± 0.02%)}	_{651,751k (± 0.02%)}	_~	_651,477k	_652,206k	_{p=0.968 n=20}
_{Memory Allocs}	_{6,046,414 (± 0.06%)}	_{6,048,191 (± 0.05%)}	_~	_6,037,136	_6,060,222	_{p=0.277 n=20}
_{Config Time}	_0.004s	_0.004s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.123s (± 2.30%)}	_{0.124s (± 1.79%)}	_~	_0.117s	_0.134s	_{p=0.673 n=20}
_{Bind Time}	_{0.040s (±10.09%)}	_{0.039s (± 5.92%)}	_~	_0.034s	_0.054s	_{p=0.334 n=20}
_{Check Time}	_{1.051s (± 0.76%)}	_{1.052s (± 1.05%)}	_~	_1.014s	_1.104s	_{p=0.899 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{1.240s (± 0.64%)}	_{1.243s (± 0.85%)}	_~	_1.208s	_1.296s	_{p=0.878 n=20}
_{xstate-main - native}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=20}
_Symbols	_640,490	_640,490	_~	_~	_~	_{p=1.000 n=20}
_Types	_387,984	_387,984	_~	_~	_~	_{p=1.000 n=20}
_{Memory Used}	_{350,136k (± 0.04%)}	_{350,067k (± 0.03%)}	_~	_349,772k	_350,570k	_{p=0.465 n=20}
_{Memory Allocs}	_{3,969,972 (± 0.07%)}	_{3,968,979 (± 0.08%)}	_~	_3,954,226	_3,982,439	_{p=0.565 n=20}
_{Config Time}	_0.001s	_0.001s	_~	_~	_~	_{p=1.000 n=20}
_{Parse Time}	_{0.059s (± 2.53%)}	_{0.059s (± 2.80%)}	_~	_0.052s	_0.064s	_{p=0.577 n=20}
_{Bind Time}	_{0.019s (±10.79%)}	_{0.020s (±12.73%)}	_~	_0.015s	_0.033s	_{p=0.558 n=20}
_{Check Time}	_{0.381s (± 0.78%)}	_{0.381s (± 0.97%)}	_~	_0.369s	_0.395s	_{p=0.663 n=20}
_{Emit Time}	_0.000s	_0.000s	_~	_~	_~	_{p=1.000 n=20}
_{Total Time}	_{0.466s (± 0.86%)}	_{0.466s (± 1.16%)}	_~	_0.450s	_0.487s	_{p=0.733 n=20}

System info unknown

Hosts

native

Scenarios

Compiler-Unions - native
angular-1 - native
arktype - native
class-transformer - native
effect - native
mui-docs - native
sentry - native
social-app - native
strada-build-src - native
strada-compiler - native
t3code-server - native
tanstack-router - native
ts-pre-modules - native
vscode - native
webpack - native
xstate-main - native

_Benchmark	_Name	_Iterations
_Current	_pr	₂₀
_Baseline	_baseline	₂₀

Developer Information:

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typescript-automation · 2026-11-03T01:56:34Z

Ryan Cavanaugh (@RyanCavanaugh) Here are the results of running the top 400 repos with tsc comparing baseline and pr:

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fix(65069): preserve contextual types for array-destructured parameter defaults - #65070

fix(65069): preserve contextual types for array-destructured parameter defaults#65070
Timur Vural (timurzvural) wants to merge 1 commit into
microsoft:mainfrom
timurzvural:fix/65069-array-destructured-default

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