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//// [deferredLookupTypeResolution.ts]
// Repro from #17456
type StringContains<S extends string, L extends string> = (
{ [K in S]: 'true' } &
{ [key: string]: 'false' }
)[L]
type ObjectHasKey<O, L extends string> = StringContains<Extract<keyof O, string>, L>
type First<T> = ObjectHasKey<T, '0'>; // Should be deferred
type T1 = ObjectHasKey<{ a: string }, 'a'>; // 'true'
type T2 = ObjectHasKey<{ a: string }, 'b'>; // 'false'
// Verify that mapped type isn't eagerly resolved in type-to-string operation
declare function f1<A extends string, B extends string>(a: A, b: B): { [P in A | B]: any };
function f2<A extends string>(a: A) {
return f1(a, 'x');
}
function f3(x: 'a' | 'b') {
return f2(x);
}
//// [deferredLookupTypeResolution.js]
"use strict";
// Repro from #17456
function f2(a) {
return f1(a, 'x');
}
function f3(x) {
return f2(x);
}
//// [deferredLookupTypeResolution.d.ts]
declare type StringContains<S extends string, L extends string> = ({
[K in S]: 'true';
} & {
[key: string]: 'false';
})[L];
declare type ObjectHasKey<O, L extends string> = StringContains<Extract<keyof O, string>, L>;
declare type First<T> = ObjectHasKey<T, '0'>;
declare type T1 = ObjectHasKey<{
a: string;
}, 'a'>;
declare type T2 = ObjectHasKey<{
a: string;
}, 'b'>;
declare function f1<A extends string, B extends string>(a: A, b: B): {
[P in A | B]: any;
};
declare function f2<A extends string>(a: A): { [P in A | "x"]: any; };
declare function f3(x: 'a' | 'b'): {
a: any;
b: any;
x: any;
};
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