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Add tests

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This commit is contained in:
Anders Hejlsberg
2018-03-04 16:49:06 -08:00
parent 6fcc99e800
commit 19e07eaea6
1 changed files with 17 additions and 0 deletions
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17
tests/cases/conformance/types/conditional/inferTypes1.ts
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@@ -90,6 +90,15 @@ type T76<T extends T[], U extends T> = { x: T };
type T77<T> = T extends T76<infer X, infer Y> ? T76<X, Y> : never;
type T78<T> = T extends T76<infer X, infer X> ? T76<X, X> : never;
type Foo<T extends string, U extends T> = [T, U];
type Bar<T> = T extends Foo<infer X, infer Y> ? Foo<X, Y> : never;
type T90 = Bar<[string, string]>; // [string, string]
type T91 = Bar<[string, "a"]>; // [string, "a"]
type T92 = Bar<[string, "a"] & { x: string }>; // [string, "a"]
type T93 = Bar<["a", string]>; // never
type T94 = Bar<[number, number]>; // never
// Example from #21496
type JsonifiedObject<T extends object> = { [K in keyof T]: Jsonified<T[K]> };
@@ -150,3 +159,11 @@ interface test {
type T80 = MatchingKeys<test, void>;
type T81 = VoidKeys<test>;
// Repro from #22221
type MustBeString<T extends string> = T;
type EnsureIsString<T> = T extends MustBeString<infer U> ? U : never;
type Test1 = EnsureIsString<"hello">; // "hello"
type Test2 = EnsureIsString<42>; // never