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//// [mappedTypeConstraints2.ts]
type Mapped1<K extends string> = { [P in K]: { a: P } };
function f1<K extends string>(obj: Mapped1<K>, key: K) {
const x: { a: K } = obj[key];
}
type Mapped2<K extends string> = { [P in K as `get${P}`]: { a: P } };
function f2<K extends string>(obj: Mapped2<K>, key: `get${K}`) {
const x: { a: K } = obj[key]; // Error
}
type Mapped3<K extends string> = { [P in K as Uppercase<P>]: { a: P } };
function f3<K extends string>(obj: Mapped3<K>, key: Uppercase<K>) {
const x: { a: K } = obj[key]; // Error
}
// Repro from #47794
type Foo<T extends string> = {
[RemappedT in T as `get${RemappedT}`]: RemappedT;
};
const get = <T extends string>(t: T, foo: Foo<T>): T => foo[`get${t}`]; // Type 'Foo<T>[`get${T}`]' is not assignable to type 'T'
// Repro from #48626
interface Bounds {
min: number;
max: number;
}
type NumericBoundsOf<T> = {
[K in keyof T as T[K] extends number | undefined ? K : never]: Bounds;
}
function validate<T extends object>(obj: T, bounds: NumericBoundsOf<T>) {
for (const [key, val] of Object.entries(obj)) {
const boundsForKey = bounds[key as keyof NumericBoundsOf<T>];
if (boundsForKey) {
const { min, max } = boundsForKey;
if (min > val || max < val) return false;
}
}
return true;
}
//// [mappedTypeConstraints2.js]
"use strict";
function f1(obj, key) {
const x = obj[key];
}
function f2(obj, key) {
const x = obj[key]; // Error
}
function f3(obj, key) {
const x = obj[key]; // Error
}
const get = (t, foo) => foo[`get${t}`]; // Type 'Foo<T>[`get${T}`]' is not assignable to type 'T'
function validate(obj, bounds) {
for (const [key, val] of Object.entries(obj)) {
const boundsForKey = bounds[key];
if (boundsForKey) {
const { min, max } = boundsForKey;
if (min > val || max < val)
return false;
}
}
return true;
}
//// [mappedTypeConstraints2.d.ts]
type Mapped1<K extends string> = {
[P in K]: {
a: P;
};
};
declare function f1<K extends string>(obj: Mapped1<K>, key: K): void;
type Mapped2<K extends string> = {
[P in K as `get${P}`]: {
a: P;
};
};
declare function f2<K extends string>(obj: Mapped2<K>, key: `get${K}`): void;
type Mapped3<K extends string> = {
[P in K as Uppercase<P>]: {
a: P;
};
};
declare function f3<K extends string>(obj: Mapped3<K>, key: Uppercase<K>): void;
type Foo<T extends string> = {
[RemappedT in T as `get${RemappedT}`]: RemappedT;
};
declare const get: <T extends string>(t: T, foo: Foo<T>) => T;
interface Bounds {
min: number;
max: number;
}
type NumericBoundsOf<T> = {
[K in keyof T as T[K] extends number | undefined ? K : never]: Bounds;
};
declare function validate<T extends object>(obj: T, bounds: NumericBoundsOf<T>): boolean;
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