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tests/cases/compiler/infiniteConstraints.ts(4,37): error TS2536: Type '"val"' cannot be used to index type 'B[Exclude<keyof B, K>]'.
tests/cases/compiler/infiniteConstraints.ts(31,43): error TS2322: Type 'Value<"dup">' is not assignable to type 'never'.
tests/cases/compiler/infiniteConstraints.ts(31,63): error TS2322: Type 'Value<"dup">' is not assignable to type 'never'.
tests/cases/compiler/infiniteConstraints.ts(36,71): error TS2536: Type '"foo"' cannot be used to index type 'T[keyof T]'.
==== tests/cases/compiler/infiniteConstraints.ts (4 errors) ====
// Both of the following types trigger the recursion limiter in getImmediateBaseConstraint
type T1<B extends { [K in keyof B]: Extract<B[Exclude<keyof B, K>], { val: string }>["val"] }> = B;
type T2<B extends { [K in keyof B]: B[Exclude<keyof B, K>]["val"] }> = B;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
!!! error TS2536: Type '"val"' cannot be used to index type 'B[Exclude<keyof B, K>]'.
// Repros from #22950
type AProp<T extends { a: string }> = T
declare function myBug<
T extends { [K in keyof T]: T[K] extends AProp<infer U> ? U : never }
>(arg: T): T
const out = myBug({obj1: {a: "test"}})
type Value<V extends string = string> = Record<"val", V>;
declare function value<V extends string>(val: V): Value<V>;
declare function ensureNoDuplicates<
T extends {
[K in keyof T]: Extract<T[K], Value>["val"] extends Extract<T[Exclude<keyof T, K>], Value>["val"]
? never
: any
}
>(vals: T): void;
const noError = ensureNoDuplicates({main: value("test"), alternate: value("test2")});
const shouldBeNoError = ensureNoDuplicates({main: value("test")});
const shouldBeError = ensureNoDuplicates({main: value("dup"), alternate: value("dup")});
~~~~
!!! error TS2322: Type 'Value<"dup">' is not assignable to type 'never'.
!!! related TS6500 tests/cases/compiler/infiniteConstraints.ts:31:43: The expected type comes from property 'main' which is declared here on type '{ main: never; alternate: never; }'
~~~~~~~~~
!!! error TS2322: Type 'Value<"dup">' is not assignable to type 'never'.
!!! related TS6500 tests/cases/compiler/infiniteConstraints.ts:31:63: The expected type comes from property 'alternate' which is declared here on type '{ main: never; alternate: never; }'
// Repro from #26448
type Cond<T> = T extends number ? number : never;
declare function function1<T extends {[K in keyof T]: Cond<T[K]>}>(): T[keyof T]["foo"];
~~~~~~~~~~~~~~~~~
!!! error TS2536: Type '"foo"' cannot be used to index type 'T[keyof T]'.
// Repro from #31823
export type Prepend<Elm, T extends unknown[]> =
T extends unknown ?
((arg: Elm, ...rest: T) => void) extends ((...args: infer T2) => void) ? T2 :
never :
never;
export type ExactExtract<T, U> = T extends U ? U extends T ? T : never : never;
type Conv<T, U = T> =
{ 0: [T]; 1: Prepend<T, Conv<ExactExtract<U, T>>>;}[U extends T ? 0 : 1];
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