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tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts(7,9): error TS2322: Type 'string | undefined' is not assignable to type 'string | number'.
Type 'undefined' is not assignable to type 'string | number'.
tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts(8,9): error TS2322: Type 'string | undefined' is not assignable to type 'string | null'.
Type 'undefined' is not assignable to type 'string | null'.
tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts(10,9): error TS2322: Type 'string | undefined' is not assignable to type 'number | null'.
Type 'undefined' is not assignable to type 'number | null'.
tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts(11,9): error TS2322: Type 'string | undefined' is not assignable to type 'number | undefined'.
Type 'string' is not assignable to type 'number'.
tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts(12,9): error TS2322: Type 'string | undefined' is not assignable to type 'null | undefined'.
Type 'string' is not assignable to type 'null | undefined'.
==== tests/cases/conformance/types/intersection/intersectionWithUnionConstraint.ts (5 errors) ====
function f1<T extends string | number, U extends string | number>(x: T & U) {
// Combined constraint of 'T & U' is 'string | number'
let y: string | number = x;
}
function f2<T extends string | number | undefined, U extends string | null | undefined>(x: T & U) {
let y1: string | number = x; // Error
~~
!!! error TS2322: Type 'string | undefined' is not assignable to type 'string | number'.
!!! error TS2322: Type 'undefined' is not assignable to type 'string | number'.
let y2: string | null = x; // Error
~~
!!! error TS2322: Type 'string | undefined' is not assignable to type 'string | null'.
!!! error TS2322: Type 'undefined' is not assignable to type 'string | null'.
let y3: string | undefined = x;
let y4: number | null = x; // Error
~~
!!! error TS2322: Type 'string | undefined' is not assignable to type 'number | null'.
!!! error TS2322: Type 'undefined' is not assignable to type 'number | null'.
let y5: number | undefined = x; // Error
~~
!!! error TS2322: Type 'string | undefined' is not assignable to type 'number | undefined'.
!!! error TS2322: Type 'string' is not assignable to type 'number'.
let y6: null | undefined = x; // Error
~~
!!! error TS2322: Type 'string | undefined' is not assignable to type 'null | undefined'.
!!! error TS2322: Type 'string' is not assignable to type 'null | undefined'.
}
type T1 = (string | number | undefined) & (string | null | undefined); // string | undefined
function f3<T extends string | number | undefined>(x: T & (number | object | undefined)) {
const y: number | undefined = x;
}
function f4<T extends string | number>(x: T & (number | object)) {
const y: number = x;
}
function f5<T, U extends keyof T>(x: keyof T & U) {
let y: keyof any = x;
}
// Repro from #23648
type Example<T, U> = { [K in keyof T]: K extends keyof U ? UnexpectedError<K> : NoErrorHere<K> }
type UnexpectedError<T extends PropertyKey> = T
type NoErrorHere<T extends PropertyKey> = T
// Repro from #30331
type a<T> = T extends Array<infer U> ? U : never;
type b<T> = { [K in a<T> & keyof T ]: 42 };
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