Improve constraints of nested conditional types applied to constrained type variables by Andarist · Pull Request #59886 · microsoft/TypeScript

Mateusz Burzyński (Andarist) · 2024-09-07T08:07:34Z

this is an extension of #56004

…d type variables

Mateusz Burzyński (Andarist) · 2024-09-07T08:11:51Z

+ if (checkType.flags & TypeFlags.Any || distributiveConditionalConstraintIdentityStack.length !== 0 && !(inferredExtendsType.flags & TypeFlags.Never) && someType(getPermissiveInstantiation(inferredExtendsType), t => isTypeAssignableTo(t, getPermissiveInstantiation(checkType)))) {
+ (extraTypes ??= []).push(instantiateType(getTypeFromTypeNode(root.node.trueType), combinedMapper || mapper));


this is the core of the fix, previously only the first level of nested conditional type (in non tail-recursive scenarios) was including the instantiated true type in its extraTypes (the reasoning behind that is outlined in the comment above and in the #56004 's description)
So now we are including it at all nested levels. In other words - previously the forConstraint was only passed to the direct call of getConditionalTypeInstantiation from getConstraintOfDistributiveConditionalType but now this contextual~ information is used for all nested calls.
I've used a global variable to track this as it's not really feasible today to thread this through instantiateType here.

Why is it not feasible to thread forConstraint through instantiateType?

Conditional types could appear just at any deeper level of the instantiated type. It's doable to introduce some kind of InstantiationFlags and pass it down to all called functions etc but it felt more complicated to attempt doing it. It would also be fairly easy to forget to pass that down somewhere.

Mateusz Burzyński (Andarist) · 2024-09-07T08:15:11Z

+function f9<S extends string>(
+ x: IsMatchingStringInfiniteRecursionInFalseType2<S>,
+) {
+ let t1: 1 = x; // Error


The error here changed from "Type instantiation is excessively deep and possibly infinite" to "Type '1 | 2' is not assignable to type '1'".
It feels fine here but perhaps it's not fine in general case and I should only return neverType for recursive calls when the compiler is instantiating for the true type. This change comes from the fact that I'm letting the neverType to be returned for any recursive call and this one comes from the false type.

Gabriela Araujo Britto (gabritto) · 2024-09-09T17:56:43Z

TypeScript Bot (@typescript-bot) test it

TypeScript Bot (typescript-bot) · 2024-09-09T17:56:47Z

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 (typescript-bot) · 2024-09-09T18:17:17Z

Hey Gabriela Araujo Britto (@gabritto), the results of running the DT tests are ready.

There were interesting changes:

Branch only errors:

Package: frida-gum
Error:

Error: /mnt/vss/_work/1/DefinitelyTyped/types/frida-gum/frida-gum-tests.ts
126:1 error TypeScript@local expected type to be:
NativeFunction<[number, number], [number | Int64, [number, [NativePointerValue, NativePointerValue]]]>
got:
NativeFunction<[number, number], never> @definitelytyped/expect
128:5 error TypeScript@local compile error: Argument of type '[Int64, (number | NativePointer[])[]]' is not assignable to parameter of type 'never' @definitelytyped/expect
130:5 error TypeScript@local compile error: Argument of type '[number, (number | NativePointer[])[]]' is not assignable to parameter of type 'never' @definitelytyped/expect
133:1 error TypeScript@local expected type to be:
NativeFunction<void, [number, ...NativePointerValue[]]>
got:
NativeFunction<void, never> @definitelytyped/expect
135:5 error TypeScript@local compile error: Argument of type '[number, NativePointer, NativeFunction<void, never>, { handle: NativePointer; }]' is not assignable to parameter of type 'never' @definitelytyped/expect
138:1 error TypeScript@local expected type to be:
NativeFunction<number, [NativePointerValue]>
got:
NativeFunction<number, never> @definitelytyped/expect
144:22 error TypeScript@local compile error: Argument of type '[NativePointer]' is not assignable to parameter of type 'never' @definitelytyped/expect
147:23 error TypeScript@local compile error: Argument of type 'NativePointer[]' is not assignable to parameter of type 'never' @definitelytyped/expect
150:6 error TypeScript@local compile error: Argument of type '[NativePointer]' is not assignable to parameter of type 'never' @definitelytyped/expect
153:1 error TypeScript@local expected type to be:
SystemFunction<number, [NativePointerValue, number]>
got:
SystemFunction<number, never> @definitelytyped/expect
158:21 error TypeScript@local compile error: Argument of type '[NativePointer, number]' is not assignable to parameter of type 'never' @definitelytyped/expect
✖ 11 problems (11 errors, 0 warnings)
at combineErrorsAndWarnings (/mnt/vss/_work/1/DefinitelyTyped/node_modules/.pnpm/@definitelytyped+dtslint@0.2.23_typescript@5.7.0-dev.20240904/node_modules/@definitelytyped/dtslint/dist/index.js:194:28)
at runTests (/mnt/vss/_work/1/DefinitelyTyped/node_modules/.pnpm/@definitelytyped+dtslint@0.2.23_typescript@5.7.0-dev.20240904/node_modules/@definitelytyped/dtslint/dist/index.js:186:20)

Package: ramda
Error:

Error: /mnt/vss/_work/1/DefinitelyTyped/types/ramda/test/converge-tests.ts
17:5 error TypeScript@local expected type to be:
Curry<(args_0: FormatSpec) => string>
got:
Curry<(args_0: FormatSpec) => never> @definitelytyped/expect
26:5 error TypeScript@local expected type to be:
string
got:
never @definitelytyped/expect
144:5 error TypeScript@local expected type to be:
Curry<(a: number, b: number) => number>
got:
Curry<(a: number, b: number) => never> @definitelytyped/expect
153:5 error TypeScript@local expected type to be:
Curry<(a: number, b: number, c: number) => number>
got:
Curry<(a: number, b: number, c: number) => <U>(b: U) => any> @definitelytyped/expect
153:55 error TypeScript@local compile error: A spread argument must either have a tuple type or be passed to a rest parameter @definitelytyped/expect
153:58 error TypeScript@local compile error: Type 'never' must have a '[Symbol.iterator]()' method that returns an iterator @definitelytyped/expect
162:5 error TypeScript@local expected type to be:
Curry<(list: readonly number[] & { length: number; }) => number>
got:
Curry<(list: readonly number[] & { length: number; }) => ((b: number) => number) & ((a: number) => number) & number> @definitelytyped/expect
162:57 error TypeScript@local compile error: A spread argument must either have a tuple type or be passed to a rest parameter @definitelytyped/expect
162:60 error TypeScript@local compile error: Type 'never' must have a '[Symbol.iterator]()' method that returns an iterator @definitelytyped/expect
166:5 error TypeScript@local expected type to be:
number
got:
((b: number) => number) & ((a: number) => number) & number @definitelytyped/expect
✖ 10 problems (10 errors, 0 warnings)
at combineErrorsAndWarnings (/mnt/vss/_work/1/DefinitelyTyped/node_modules/.pnpm/@definitelytyped+dtslint@0.2.23_typescript@5.7.0-dev.20240904/node_modules/@definitelytyped/dtslint/dist/index.js:194:28)
at runTests (/mnt/vss/_work/1/DefinitelyTyped/node_modules/.pnpm/@definitelytyped+dtslint@0.2.23_typescript@5.7.0-dev.20240904/node_modules/@definitelytyped/dtslint/dist/index.js:186:20)

Package: styled-components
Error:

Error: /mnt/vss/_work/1/DefinitelyTyped/types/styled-components/test/index.tsx
631:38 error TypeScript@local compile error: No overload matches this call.
Overload 1 of 2, '(props: { a?: number | undefined; b: number; className?: string | undefined; } & { theme?: any; } & { as?: undefined; forwardedAs?: undefined; }): ReactElement<WithOptionalTheme<{ b: number; className?: string | undefined; } & Partial<...>, any>, string | JSXElementConstructor<...>>', gave the following error.
Type '{ b: number; color: string; }' is not assignable to type 'IntrinsicAttributes & { a?: number | undefined; b: number; className?: string | undefined; } & { theme?: any; } & { as?: undefined; forwardedAs?: undefined; }'.
Property 'color' does not exist on type 'IntrinsicAttributes & { a?: number | undefined; b: number; className?: string | undefined; } & { theme?: any; } & { as?: undefined; forwardedAs?: undefined; }'.
Overload 2 of 2, '(props: StyledComponentPropsWithAs<FC<{ b: number; className?: string | undefined; }>, any, { a: number; }, "a", FC<{ b: number; className?: string | undefined; }>, FC<{ b: number; className?: string | undefined; }>>): ReactElement<...>', gave the following error.
Type '{ b: number; color: string; }' is not assignable to type 'IntrinsicAttributes & { a?: number | undefined; b: number; className?: string | undefined; } & { theme?: any; } & { as?: FC<{ b: number; className?: string | undefined; }> | undefined; forwardedAs?: FC<...> | undefined; }'.
Property 'color' does not exist on type 'IntrinsicAttributes & { a?: number | undefined; b: number; className?: string | undefined; } & { theme?: any; } & { as?: FC<{ b: number; className?: string | undefined; }> | undefined; forwardedAs?: FC<...> | undefined; }' @definitelytyped/expect
664:10 error TypeScript@local compile error: Unused '@ts-expect-error' directive @definitelytyped/expect
782:1 error TypeScript@local compile error: Unused '@ts-expect-error' directive @definitelytyped/expect
1314:21 error TypeScript@local compile error: Argument of type 'StyledComponent<"div", any, {}, never>' is not assignable to parameter of type 'StyledComponent<any, any, any, any>'.
The types returned by 'withComponent(...)' are incompatible between these types.
Type 'StyledComponent<any, any, object, string | number | symbol>' is not assignable to type 'StyledComponent<never, any, any, any>'.
Type 'StyledComponent<any, any, object, string | number | symbol>' is not assignable to type 'StyledComponentBase<never, any, any, any>'.
Types of property 'propTypes' are incompatible.
Type 'WeakValidationMap<WithOptionalTheme<{} & Partial<{ [x: string]: any; [x: number]: any; [x: symbol]: any; }>, any>> | undefined' is not assignable to type 'undefined'.
Type 'WeakValidationMap<WithOptionalTheme<{} & Partial<{ [x: string]: any; [x: number]: any; [x: symbol]: any; }>, any>>' is not assignable to type 'undefined' @definitelytyped/expect
1315:24 error TypeScript@local compile error: Argument of type 'StyledComponent<"div", any, {}, never>' is not assignable to parameter of type 'StyledComponent<any, any, any, any>'.
The types returned by 'withComponent(...)' are incompatible between these types.
Type 'StyledComponent<any, any, object, string | number | symbol>' is not assignable to type 'StyledComponent<never, any, any, any>'.
Type 'StyledComponent<any, any, object, string | number | symbol>' is not assignable to type 'StyledComponentBase<never, any, any, any>'.
Types of property 'propTypes' are incompatible.
Type 'WeakValidationMap<WithOptionalTheme<{} & Partial<{ [x: string]: any; [x: number]: any; [x: symbol]: any; }>, any>> | undefined' is not assignable to type 'undefined'.
Type 'WeakValidationMap<WithOptionalTheme<{} & Partial<{ [x: string]: any; [x: number]: any; [x: symbol]: any; }>, any>>' is not assignable to type 'undefined' @definitelytyped/expect
1316:37 error TypeScript@local compile error: Argument of type 'StyledComponent<"div", any, {}, never>' is not assignable to parameter of type 'StyledComponent<any, any, any, any>'.
The types returned by 'withComponent(...)' are incompatible between these types.
Type 'StyledComponent<any, any, object, string | number | symbol>' is not assignable to type 'StyledComponent<never, any, any, any>'.
Type 'StyledComponent<any, any, object, string | number | symbol>' is not assignable to type 'StyledComponentBase<never, any, any, any>'.
Types of property 'propTypes' are incompatible.
Type 'WeakValidationMap<WithOptionalTheme<{} & Partial<{ [x: string]: any; [x: number]: any; [x: symbol]: any; }>, any>> | undefined' is not assignable to type 'undefined'.
Type 'WeakValidationMap<WithOptionalTheme<{} & Partial<{ [x: string]: any; [x: number]: any; [x: symbol]: any; }>, any>>' is not assignable to type 'undefined' @definitelytyped/expect
✖ 6 problems (6 errors, 0 warnings)
at combineErrorsAndWarnings (/mnt/vss/_work/1/DefinitelyTyped/node_modules/.pnpm/@definitelytyped+dtslint@0.2.23_typescript@5.7.0-dev.20240904/node_modules/@definitelytyped/dtslint/dist/index.js:194:28)
at runTests (/mnt/vss/_work/1/DefinitelyTyped/node_modules/.pnpm/@definitelytyped+dtslint@0.2.23_typescript@5.7.0-dev.20240904/node_modules/@definitelytyped/dtslint/dist/index.js:186:20)

You can check the log here.

TypeScript Bot (typescript-bot) · 2024-09-09T18:23:19Z

Gabriela Araujo Britto (@gabritto) Here are the results of running the user tests with tsc comparing main and refs/pull/59886/merge:

Everything looks good!

TypeScript Bot (typescript-bot) · 2024-09-09T18:42:40Z

Gabriela Araujo Britto (@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	₃₀	₃₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_62,153	_62,153	_~	_~	_~	_{p=1.000 n=6}
_Types	_50,242	_50,242	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{194,175k (± 0.99%)}	_{193,611k (± 0.89%)}	_~	_192,361k	_195,869k	_{p=0.378 n=6}
_{Parse Time}	_{1.57s (± 1.12%)}	_{1.56s (± 1.37%)}	_~	_1.53s	_1.58s	_{p=0.744 n=6}
_{Bind Time}	_{0.85s (± 1.43%)}	_{0.86s (± 0.88%)}	_~	_0.85s	_0.87s	_{p=0.555 n=6}
_{Check Time}	_{11.38s (± 0.69%)}	_{11.37s (± 0.41%)}	_~	_11.30s	_11.43s	_{p=0.748 n=6}
_{Emit Time}	_{3.23s (± 0.77%)}	_{3.25s (± 0.61%)}	_~	_3.22s	_3.27s	_{p=0.086 n=6}
_{Total Time}	_{17.03s (± 0.50%)}	_{17.05s (± 0.44%)}	_~	_16.94s	_17.14s	_{p=0.872 n=6}
_{angular-1 - node (v18.15.0, x64)}
_Errors	₇	₇	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_945,753	_945,753	_~	_~	_~	_{p=1.000 n=6}
_Types	_410,067	_410,067	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{1,222,752k (± 0.00%)}	_{1,222,707k (± 0.00%)}	_{-45k (- 0.00%)}	_1,222,670k	_1,222,739k	_{p=0.045 n=6}
_{Parse Time}	_{7.91s (± 0.69%)}	_{7.95s (± 0.74%)}	_~	_7.87s	_8.05s	_{p=0.334 n=6}
_{Bind Time}	_{2.22s (± 0.62%)}	_{2.23s (± 0.46%)}	_~	_2.21s	_2.24s	_{p=0.134 n=6}
_{Check Time}	_{36.47s (± 0.38%)}	_{36.44s (± 0.30%)}	_~	_36.27s	_36.56s	_{p=0.688 n=6}
_{Emit Time}	_{17.81s (± 0.66%)}	_{17.86s (± 0.30%)}	_~	_17.78s	_17.91s	_{p=0.567 n=6}
_{Total Time}	_{64.41s (± 0.26%)}	_{64.47s (± 0.16%)}	_~	_64.36s	_64.64s	_{p=0.468 n=6}
_{mui-docs - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,506,932	_2,506,924	_{-8 (- 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_932,998	_933,020	_{+22 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{2,336,496k (± 0.00%)}	_{2,336,496k (± 0.00%)}	_~	_2,336,419k	_2,336,652k	_{p=0.378 n=6}
_{Parse Time}	_{10.98s (± 0.25%)}	_{10.99s (± 0.51%)}	_~	_10.92s	_11.09s	_{p=0.872 n=6}
_{Bind Time}	_{2.56s (± 0.21%)}	_{2.56s (± 0.52%)}	_~	_2.54s	_2.57s	_{p=0.242 n=6}
_{Check Time}	_{85.20s (± 0.36%)}	_{85.50s (± 0.51%)}	_~	_85.00s	_86.26s	_{p=0.230 n=6}
_{Emit Time}	_{0.33s (± 1.58%)}	_{0.32s (± 1.27%)}	_~	_0.32s	_0.33s	_{p=0.112 n=6}
_{Total Time}	_{99.06s (± 0.33%)}	_{99.37s (± 0.42%)}	_~	_98.87s	_100.12s	_{p=0.297 n=6}
_{self-build-src - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,247,213	_1,247,214	_{+1 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_265,146	_265,146	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,457,700k (± 5.94%)}	_{2,397,797k (± 0.03%)}	_~	_2,397,059k	_2,398,898k	_{p=0.378 n=6}
_{Parse Time}	_{6.02s (± 1.16%)}	_{6.02s (± 0.51%)}	_~	_5.98s	_6.06s	_{p=1.000 n=6}
_{Bind Time}	_{2.29s (± 0.46%)}	_{2.29s (± 0.64%)}	_~	_2.27s	_2.31s	_{p=0.463 n=6}
_{Check Time}	_{41.15s (± 0.75%)}	_{41.18s (± 0.54%)}	_~	_40.87s	_41.45s	_{p=0.810 n=6}
_{Emit Time}	_{3.99s (± 2.58%)}	_{4.00s (± 3.10%)}	_~	_3.91s	_4.25s	_{p=0.810 n=6}
_{Total Time}	_{53.48s (± 0.56%)}	_{53.52s (± 0.44%)}	_~	_53.16s	_53.78s	_{p=0.873 n=6}
_{self-build-src-public-api - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,247,213	_1,247,214	_{+1 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_265,146	_265,146	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,472,855k (± 0.04%)}	_{2,472,668k (± 0.01%)}	_~	_2,472,375k	_2,472,977k	_{p=0.810 n=6}
_{Parse Time}	_{7.82s (± 0.58%)}	_{7.84s (± 0.56%)}	_~	_7.76s	_7.89s	_{p=0.296 n=6}
_{Bind Time}	_{2.53s (± 1.05%)}	_{2.54s (± 0.43%)}	_~	_2.52s	_2.55s	_{p=0.227 n=6}
_{Check Time}	_{51.28s (± 0.69%)}	_{51.05s (± 0.57%)}	_~	_50.79s	_51.55s	_{p=0.230 n=6}
_{Emit Time}	_{5.03s (± 3.74%)}	_{4.98s (± 3.27%)}	_~	_4.86s	_5.31s	_{p=0.689 n=6}
_{Total Time}	_{66.68s (± 0.60%)}	_{66.41s (± 0.47%)}	_~	_66.05s	_66.92s	_{p=0.230 n=6}
_{self-compiler - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_259,149	_259,150	_{+1 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_105,986	_105,986	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{433,473k (± 0.03%)}	_{433,561k (± 0.03%)}	_~	_433,402k	_433,726k	_{p=0.230 n=6}
_{Parse Time}	_{4.23s (± 1.01%)}	_{4.24s (± 0.63%)}	_~	_4.20s	_4.28s	_{p=0.414 n=6}
_{Bind Time}	_{1.58s (± 0.52%)}	_{1.58s (± 0.69%)}	_~	_1.57s	_1.60s	_{p=0.666 n=6}
_{Check Time}	_{22.40s (± 0.22%)}	_{22.31s (± 0.41%)}	_~	_22.22s	_22.43s	_{p=0.196 n=6}
_{Emit Time}	_{2.06s (± 0.85%)}	_{2.07s (± 0.71%)}	_~	_2.04s	_2.08s	_{p=0.145 n=6}
_{Total Time}	_{30.25s (± 0.26%)}	_{30.21s (± 0.28%)}	_~	_30.13s	_30.33s	_{p=0.423 n=6}
_{ts-pre-modules - node (v18.15.0, x64)}
_Errors	₆₈	₆₈	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_225,018	_225,018	_~	_~	_~	_{p=1.000 n=6}
_Types	_94,249	_94,249	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{370,264k (± 0.02%)}	_{370,295k (± 0.02%)}	_~	_370,208k	_370,439k	_{p=0.378 n=6}
_{Parse Time}	_{2.76s (± 0.23%)}	_{2.76s (± 1.01%)}	_~	_2.72s	_2.79s	_{p=0.739 n=6}
_{Bind Time}	_{1.58s (± 1.16%)}	_{1.56s (± 0.52%)}	_~	_1.55s	_1.57s	_{p=0.116 n=6}
_{Check Time}	_{15.74s (± 0.35%)}	_{15.77s (± 0.19%)}	_~	_15.73s	_15.82s	_{p=0.419 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{20.08s (± 0.38%)}	_{20.09s (± 0.27%)}	_~	_20.02s	_20.17s	_{p=0.936 n=6}
_{vscode - node (v18.15.0, x64)}
_Errors	₁	₁	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_3,041,302	_3,041,302	_~	_~	_~	_{p=1.000 n=6}
_Types	_1,051,790	_1,051,791	_{+1 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{3,149,771k (± 0.00%)}	_{3,149,816k (± 0.00%)}	_~	_3,149,742k	_3,149,937k	_{p=0.261 n=6}
_{Parse Time}	_{16.96s (± 0.38%)}	_{17.00s (± 0.33%)}	_~	_16.93s	_17.09s	_{p=0.518 n=6}
_{Bind Time}	_{5.37s (± 2.30%)}	_{5.29s (± 0.28%)}	_~	_5.27s	_5.31s	_{p=0.252 n=6}
_{Check Time}	_{98.92s (± 0.44%)}	_{98.92s (± 0.19%)}	_~	_98.61s	_99.12s	_{p=0.810 n=6}
_{Emit Time}	_{27.00s (± 1.10%)}	_{26.99s (± 0.64%)}	_~	_26.70s	_27.17s	_{p=0.748 n=6}
_{Total Time}	_{148.26s (± 0.30%)}	_{148.20s (± 0.24%)}	_~	_147.73s	_148.69s	_{p=0.936 n=6}
_{webpack - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_277,022	_277,022	_~	_~	_~	_{p=1.000 n=6}
_Types	_112,817	_112,817	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{426,739k (± 0.01%)}	_{426,727k (± 0.01%)}	_~	_426,641k	_426,806k	_{p=0.689 n=6}
_{Parse Time}	_{3.30s (± 0.30%)}	_{3.30s (± 0.38%)}	_~	_3.28s	_3.31s	_{p=0.931 n=6}
_{Bind Time}	_{1.44s (± 0.98%)}	_{1.43s (± 0.84%)}	_~	_1.42s	_1.45s	_{p=0.458 n=6}
_{Check Time}	_{14.98s (± 0.78%)}	_{14.95s (± 0.25%)}	_~	_14.88s	_14.98s	_{p=0.375 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{19.72s (± 0.68%)}	_{19.68s (± 0.14%)}	_~	_19.64s	_19.71s	_{p=0.296 n=6}
_{xstate-main - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_539,317	_539,499	_{+182 (+ 0.03%)}	_~	_~	_{p=0.001 n=6}
_Types	_178,997	_179,127	_{+130 (+ 0.07%)}	_~	_~	_{p=0.001 n=6}
_{Memory used}	_{484,254k (± 0.03%)}	_{484,331k (± 0.05%)}	_~	_484,130k	_484,703k	_{p=0.810 n=6}
_{Parse Time}	_{3.42s (± 0.44%)}	_{3.42s (± 0.44%)}	_~	_3.39s	_3.43s	_{p=1.000 n=6}
_{Bind Time}	_{1.26s (± 0.67%)}	_{1.26s (± 0.66%)}	_~	_1.25s	_1.27s	_{p=0.084 n=6}
_{Check Time}	_{18.32s (± 0.37%)}	_{18.43s (± 0.42%)}	_~	_18.32s	_18.54s	_{p=0.065 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{22.99s (± 0.29%)}	_{23.10s (± 0.31%)}	_{+0.11s (+ 0.48%)}	_23.02s	_23.20s	_{p=0.044 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 (typescript-bot) · 2024-09-09T19:31:11Z

Gabriela Araujo Britto (@gabritto) Here are the results of running the top 400 repos with tsc comparing main and refs/pull/59886/merge:

Something interesting changed - please have a look.

Details

actualbudget/actual

2 of 5 projects failed to build with the old tsc and were ignored

packages/loot-core/tsconfig.api.json

error TS2345: Argument of type '{ id: any; }' is not assignable to parameter of type 'never'.
- packages/api/methods.ts#L27
error TS2322: Type '(args_0: { id: any; fields: any; }) => Promise<any[]>' is not assignable to type '(arg: { id: any; fields: any; }) => Promise<never>'.
- packages/loot-core/src/server/api.ts#L493
error TS2322: Type '(args_0: { id: any; }) => Promise<any[]>' is not assignable to type '(arg: { id: any; }) => Promise<never>'.
- packages/loot-core/src/server/api.ts#L511
error TS2322: Type '({ added, deleted, updated, learnCategories, }: Partial<Diff<TransactionEntity>> & { learnCategories?: boolean; detectOrphanPayees?: boolean; runTransfers?: boolean; }) => Promise<{ added: TransactionEntity[]; updated: TransactionEntity[] | ({ ...; } | ... 1 more ... | { ...; })[]; }>' is not assignable to type '(arg_0: Partial<Diff<TransactionEntity>> & { learnCategories?: boolean; detectOrphanPayees?: boolean; runTransfers?: boolean; }) => never'.
- packages/loot-core/src/server/main.ts#L106
error TS2345: Argument of type 'Parameters<T>[0]' is not assignable to parameter of type 'never'.
- packages/loot-core/src/server/mutators.ts#L54
- packages/loot-core/src/server/mutators.ts#L67

adonisjs/core

tsconfig.json

error TS2536: Type '"list"' cannot be used to index type 'Awaited<ReturnType<T["resolver"]>>'.
- src/types.ts#L62

gvergnaud/ts-pattern

1 of 4 projects failed to build with the old tsc and were ignored

examples/one-file-demo/tsconfig.json

error TS2578: Unused '@ts-expect-error' directive.
- examples/one-file-demo/one-file-demo.ts#L49

noodle-run/noodle

tsconfig.json

error TS2339: Property 'DATABASE_URL' does not exist on type 'never'.
- drizzle.config.ts#L12
- src/db/index.ts#L8
error TS2339: Property 'NODE_ENV' does not exist on type 'never'.
error TS2339: Property 'VERCEL_URL' does not exist on type 'never'.
- src/emails/utils.ts#L13
- src/emails/utils.ts#L14
error TS2339: Property 'UPSTASH_REDIS_REST_URL' does not exist on type 'never'.
- src/lib/redis.ts#L6
error TS2339: Property 'UPSTASH_REDIS_REST_TOKEN' does not exist on type 'never'.
- src/lib/redis.ts#L7
error TS2339: Property 'RESEND_API_KEY' does not exist on type 'never'.
- src/lib/resend.ts#L4
error TS2339: Property 'PORT' does not exist on type 'never'.
- src/lib/utils.ts#L36

peers/peerjs

tsconfig.json

error TS2339: Property 'type' does not exist on type 'never'.
- __test__/peer.spec.ts#L204
error TS2345: Argument of type '[Unpackable]' is not assignable to parameter of type 'never'.
- lib/dataconnection/BufferedConnection/BinaryPack.ts#L47
error TS2345: Argument of type '[any]' is not assignable to parameter of type 'never'.
error TS2345: Argument of type '[]' is not assignable to parameter of type 'never'.
error TS2345: Argument of type '[unknown]' is not assignable to parameter of type 'never'.
- lib/dataconnection/StreamConnection/MsgPack.ts#L19
error TS2345: Argument of type '[RTCIceConnectionState]' is not assignable to parameter of type 'Parameters<EventListener<Events & BaseConnectionEvents<BaseConnectionErrorType>, "iceStateChanged">>'.
- lib/negotiator.ts#L125
error TS2345: Argument of type '[string]' is not assignable to parameter of type 'never'.
- lib/peer.ts#L358
- lib/peer.ts#L699
error TS2345: Argument of type '[MediaConnection]' is not assignable to parameter of type 'never'.
- lib/peer.ts#L404
error TS2345: Argument of type '[DataConnection]' is not assignable to parameter of type 'never'.
- lib/peer.ts#L421

refined-github/refined-github

tsconfig.json

error TS2339: Property 'customCSS' does not exist on type 'never'.
- source/feature-manager.tsx#L144
- source/feature-manager.tsx#L146
error TS2339: Property 'logging' does not exist on type 'never'.
- source/feature-manager.tsx#L158
error TS2339: Property 'logHTTP' does not exist on type 'never'.
- source/feature-manager.tsx#L162
error TS2339: Property 'label' does not exist on type '{}'.
- source/features/bugs-tab.tsx#L49
error TS2488: Type 'never' must have a '[Symbol.iterator]()' method that returns an iterator.
- source/features/github-actions-indicators.tsx#L67
error TS2339: Property 'includes' does not exist on type 'never'.
- source/features/github-actions-indicators.tsx#L80
error TS2339: Property 'repository' does not exist on type 'never'.
- source/features/highlight-non-default-base-branch.tsx#L42
error TS2322: Type 'RestResponse' is not assignable to type 'never'.
- source/github-helpers/api.ts#L139
error TS2322: Type '{ readonly get: (path: string) => Promise<string | undefined>; readonly set: (path: string, contents: string) => Promise<void>; readonly has: (path: string) => Promise<boolean>; readonly delete: (path: string) => Promise<...>; }' is not assignable to type 'false | CacheStorage<string, never> | undefined'.
- source/github-helpers/selectors.test.ts#L50

vuejs/pinia

5 of 7 projects failed to build with the old tsc and were ignored

tsconfig.json

error TS2339: Property 'values' does not exist on type 'never'.
error TS2339: Property 'entries' does not exist on type 'never'.

TypeScript Bot (typescript-bot) · 2024-09-09T19:31:12Z

Gabriela Araujo Britto (@gabritto) Here are some more interesting changes from running the top 400 repos suite

Details

vuetifyjs/vuetify

3 of 7 projects failed to build with the old tsc and were ignored

packages/vuetify/tsconfig.json

error TS2322: Type 'number' is not assignable to type 'undefined'.
error TS2322: Type 'string' is not assignable to type 'undefined'.
error TS2322: Type 'true' is not assignable to type 'undefined'.
error TS2322: Type '"small" | "default" | "large" | "x-large" | "x-small"' is not assignable to type 'undefined'.
- packages/vuetify/src/components/VBtn/__tests__/VBtn.spec.cy.tsx#L40
error TS2345: Argument of type 'LooseRequired<{ readonly reverse: boolean; readonly style: StyleValue; readonly height: never; readonly disabled: boolean; readonly tag: string; readonly mandatory: boolean | "force"; readonly direction: "horizontal" | "vertical"; readonly selectedClass: string; readonly nextIcon: IconValue; readonly prevIcon: IconValue; readonly showArrows: string | boolean; readonly continuous: boolean; readonly cycle: boolean; readonly delimiterIcon: IconValue; readonly hideDelimiters: boolean; readonly hideDelimiterBackground: boolean; readonly interval: never; readonly class?: any; readonly progress?: undefined; readonly theme?: string | undefined; readonly color?: string | undefined; readonly modelValue?: any; readonly touch?: boolean | TouchHandlers | undefined; readonly verticalDelimiters?: boolean | "left" | "right" | undefined; readonly "onUpdate:modelValue"?: ((value: any) => any) | undefined; } & {}>' is not assignable to parameter of type 'Partial<ExtractPropTypes<AppendDefault<{ theme: StringConstructor; tag: { type: StringConstructor; default: string; }; class: PropType<ClassValue>; style: { type: PropType<StyleValue>; default: null; }; continuous: BooleanConstructor; nextIcon: { type: PropType<IconValue>; default: string; }; prevIcon: { type: PropType<IconValue>; default: string; }; reverse: BooleanConstructor; showArrows: { type: (StringConstructor | BooleanConstructor)[]; validator: (v: any) => boolean; }; touch: { type: PropType<boolean | TouchHandlers>; default: undefined; }; direction: { type: PropType<"horizontal" | "vertical">; default: string; }; modelValue: null; disabled: BooleanConstructor; selectedClass: { type: StringConstructor; default: string; }; mandatory: { type: PropType<boolean | "force">; default: "force"; }; }, {}>>>'.
- packages/vuetify/src/components/VCarousel/VCarousel.tsx#L106
error TS2345: Argument of type 'LooseRequired<{ readonly style: StyleValue; readonly mode: "rgb" | "rgba" | "hsl" | "hsla" | "hex" | "hexa"; readonly width: string | number; readonly disabled: boolean; readonly tag: string; readonly tile: boolean; readonly dotSize: never; readonly modes: readonly ("rgb" | "rgba" | "hsl" | "hsla" | "hex" | "hexa")[]; readonly canvasHeight: never; readonly hideCanvas: boolean; readonly hideSliders: boolean; readonly hideInputs: boolean; readonly showSwatches: boolean; readonly swatchesMaxHeight: never; readonly class?: any; readonly theme?: string | undefined; readonly color?: string | undefined; readonly border?: undefined; readonly position?: "fixed" | "sticky" | "absolute" | "relative" | "static" | undefined; readonly modelValue?: string | Record<string, unknown> | null | undefined; readonly rounded?: undefined; readonly elevation?: undefined; readonly swatches?: readonly (readonly (string | number | { readonly r: number; readonly g: number; readonly b: number; readonly a?: number | undefined; } | { readonly h: number; readonly s: number; readonly v: number; readonly a?: number | undefined; } | { readonly h: number; readonly s: number; readonly l: number; readonly a?: number | undefined; })[])[] | undefined; readonly "onUpdate:modelValue"?: ((color: any) => any) | undefined; readonly "onUpdate:mode"?: ((mode: "rgb" | "rgba" | "hsl" | "hsla" | "hex" | "hexa") => any) | undefined; } & {}>' is not assignable to parameter of type 'Partial<ExtractPropTypes<AppendDefault<{ theme: StringConstructor; tag: { type: StringConstructor; default: string; }; rounded: { type: (StringConstructor | NumberConstructor | BooleanConstructor)[]; default: undefined; }; tile: BooleanConstructor; position: { type: PropType<Position>; validator: (v: any) => boolean; }; location: PropType<Anchor | null>; elevation: { type: (StringConstructor | NumberConstructor)[]; validator(v: any): boolean; }; height: (StringConstructor | NumberConstructor)[]; maxHeight: (StringConstructor | NumberConstructor)[]; maxWidth: (StringConstructor | NumberConstructor)[]; minHeight: (StringConstructor | NumberConstructor)[]; minWidth: (StringConstructor | NumberConstructor)[]; width: (StringConstructor | NumberConstructor)[]; class: PropType<ClassValue>; style: { type: PropType<StyleValue>; default: null; }; border: (StringConstructor | NumberConstructor | BooleanConstructor)[]; color: StringConstructor; }, {}>>>'.
- packages/vuetify/src/components/VColorPicker/VColorPicker.tsx#L141
error TS2322: Type 'string | number' is not assignable to type 'undefined'.
error TS2322: Type 'number | undefined' is not assignable to type 'undefined'.
- packages/vuetify/src/components/VColorPicker/VColorPickerPreview.tsx#L86
- packages/vuetify/src/components/VTabs/VTab.tsx#L123
error TS2322: Type 'number' is not assignable to type 'never'.
`` error TS2322: Type '{ "onUpdate:options": (opts: { page: number; itemsPerPage: number; }) => void; itemsLength: number; page: number; itemsPerPage: number; headers: { title: string; key: string; }[]; items: any[]; }' is not assignable to type 'IntrinsicAttributes & Partial<{ style: StyleValue; sticky: boolean; tag: string; noDataText: string; loadingText: string; itemsPerPageText: string; sortBy: readonly SortItem[]; pageText: string; page: never; mobile: boolean | null; groupBy: readonly SortItem[]; expanded: readonly string[]; density: Density; valueComparator: (a: any, b: any) => boolean; nextIcon: IconValue; prevIcon: IconValue; selectStrategy: "page" | "all" | "single"; returnObject: boolean; hideNoData: boolean; hover: boolean; multiSort: boolean; mustSort: boolean; disableSort: boolean; showSelect: boolean; expandOnClick: boolean; showExpand: boolean; itemsPerPage: never; firstIcon: IconValue; lastIcon: IconValue; firstPageLabel: string; prevPageLabel: string; nextPageLabel: string; lastPageLabel: string; itemsPerPageOptions: readonly (number | { title: string; value: number; })[]; showCurrentPage: boolean; sortAscIcon: IconValue; sortDescIcon: IconValue; fixedHeader: boolean; fixedFooter: boolean; hideDefaultBody: boolean; hideDefaultFooter: boolean; hideDefaultHeader: boolean; }> & Omit<{ style: StyleValue; sticky: boolean; tag: string; noDataText: string; loadingText: string; itemsPerPageText: string; sortBy: readonly SortItem[]; pageText: string; page: never; mobile: boolean | nul
:error: Truncated - see log for full output :error:

Gabriela Araujo Britto (gabritto) · 2024-09-09T20:12:55Z

Mateusz Burzyński (@Andarist) seems like a bunch of things broke because some types became never. Maybe we're being overeager in detecting circularities?

Mateusz Burzyński (Andarist) · 2024-09-10T07:10:11Z

I have a hunch that this might be related to my comment here. I'll investigate and report back with the findings and new tests.

TypeScript Bot (typescript-bot) · 2026-03-24T21:20:06Z

With 6.0 out as the final release vehicle for this codebase, we're closing all PRs that don't fit the merge criteria for post-6.0 patches. If you think this was a mistake and this PR fits the post-6.0 patch criteria, please post to the 6.0 iteration issue with details (specifically, which PR and which patch criteria it satisfies).

Next steps for PRs:

For crash bugfixes or language service improvements, PRs are currently accepted at the typescript-go repo
Changes to type system behavior should wait until after 7.0, at which point mainline TypeScript development will resume in this repository with the Go codebase
Library file updates (lib.d.ts etc) continue to live in this repo or the DOM Generator repo as appropriate

Improve constraints of nested conditional types applied to constraine…
f83bcbc
…d type variables

TypeScript Bot (typescript-bot) added the For Backlog Bug PRs that fix a backlog bug label Sep 7, 2024

Mateusz Burzyński (Andarist) commented Sep 7, 2024
View reviewed changes

TypeScript Bot (typescript-bot) closed this Mar 24, 2026

github-project-automationBot moved this from Not started to Done in PR Backlog Mar 24, 2026

		if (checkType.flags & TypeFlags.Any \|\| distributiveConditionalConstraintIdentityStack.length !== 0 && !(inferredExtendsType.flags & TypeFlags.Never) && someType(getPermissiveInstantiation(inferredExtendsType), t => isTypeAssignableTo(t, getPermissiveInstantiation(checkType)))) {
		(extraTypes ??= []).push(instantiateType(getTypeFromTypeNode(root.node.trueType), combinedMapper \|\| mapper));

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Mateusz Burzyński (Andarist) commented Sep 7, 2024

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Gabriela Araujo Britto (gabritto) commented Sep 9, 2024

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tsc

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Gabriela Araujo Britto (gabritto) commented Sep 9, 2024

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Mateusz Burzyński (Andarist) commented Sep 10, 2024

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TypeScript Bot (typescript-bot) commented Sep 9, 2024•
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