File: inferTypeParameterConstraints.types

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//// [tests/cases/compiler/inferTypeParameterConstraints.ts] ////

=== inferTypeParameterConstraints.ts ===
// Repro from #42636

type SubGuard<A, X extends [A]> = X;
>SubGuard : X

type IsSub<M extends any[], S extends any[]> = M extends [...SubGuard<M[number], infer B>, ...S, ...any[]] ? B : never;
>IsSub : IsSub<M, S>

type E0 = IsSub<[1, 2, 3, 4], [2, 3, 4]>;  // [1 | 2 | 3 | 4]
>E0 : [1 | 4 | 2 | 3]

type E1 = [1, 2, 3, 4] extends [...infer B, 2, 3, 4, ...any[]] ? B : never;  // unknown[]
>E1 : unknown[]

// Repro from #42636

type Constrain<T extends C, C> = unknown;
>Constrain : unknown

type Foo<A> = A extends Constrain<infer X, A> ? X : never;
>Foo : Foo<A>

type T0 = Foo<string>;  // string
>T0 : string