/
conditionalTypes1.errors.txt
495 lines (413 loc) · 25.6 KB
/
conditionalTypes1.errors.txt
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tests/cases/conformance/types/conditional/conditionalTypes1.ts(12,5): error TS2322: Type 'T' is not assignable to type 'NonNullable<T>'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(17,5): error TS2322: Type 'T' is not assignable to type 'NonNullable<T>'.
Type 'string | undefined' is not assignable to type 'NonNullable<T>'.
Type 'undefined' is not assignable to type 'NonNullable<T>'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(18,9): error TS2322: Type 'T' is not assignable to type 'string'.
Type 'string | undefined' is not assignable to type 'string'.
Type 'undefined' is not assignable to type 'string'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(24,5): error TS2322: Type 'T[keyof T] | undefined' is not assignable to type 'NonNullable<Partial<T>[keyof T]>'.
Type 'undefined' is not assignable to type 'NonNullable<Partial<T>[keyof T]>'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(29,5): error TS2322: Type 'T["x"]' is not assignable to type 'NonNullable<T["x"]>'.
Type 'string | undefined' is not assignable to type 'NonNullable<T["x"]>'.
Type 'undefined' is not assignable to type 'NonNullable<T["x"]>'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(30,9): error TS2322: Type 'T["x"]' is not assignable to type 'string'.
Type 'string | undefined' is not assignable to type 'string'.
Type 'undefined' is not assignable to type 'string'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(103,5): error TS2322: Type 'Pick<T, { [K in keyof T]: T[K] extends Function ? K : never; }[keyof T]>' is not assignable to type 'T'.
'Pick<T, { [K in keyof T]: T[K] extends Function ? K : never; }[keyof T]>' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint '{}'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(104,5): error TS2322: Type 'Pick<T, { [K in keyof T]: T[K] extends Function ? never : K; }[keyof T]>' is not assignable to type 'T'.
'Pick<T, { [K in keyof T]: T[K] extends Function ? never : K; }[keyof T]>' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint '{}'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(106,5): error TS2322: Type 'Pick<T, { [K in keyof T]: T[K] extends Function ? never : K; }[keyof T]>' is not assignable to type 'Pick<T, { [K in keyof T]: T[K] extends Function ? K : never; }[keyof T]>'.
Type 'T[keyof T] extends Function ? keyof T : never' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(108,5): error TS2322: Type 'Pick<T, { [K in keyof T]: T[K] extends Function ? K : never; }[keyof T]>' is not assignable to type 'Pick<T, { [K in keyof T]: T[K] extends Function ? never : K; }[keyof T]>'.
Type 'T[keyof T] extends Function ? never : keyof T' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(114,5): error TS2322: Type 'keyof T' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
Type 'string | number | symbol' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
Type 'string' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(115,5): error TS2322: Type 'T[keyof T] extends Function ? never : keyof T' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
Type 'keyof T' is not assignable to type 'never'.
Type 'string | number | symbol' is not assignable to type 'never'.
Type 'string' is not assignable to type 'never'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(116,5): error TS2322: Type 'keyof T' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
Type 'string | number | symbol' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
Type 'string' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(117,5): error TS2322: Type 'T[keyof T] extends Function ? keyof T : never' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
Type 'keyof T' is not assignable to type 'never'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(134,10): error TS2540: Cannot assign to 'id' because it is a read-only property.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(135,5): error TS2542: Index signature in type 'DeepReadonlyArray<Part>' only permits reading.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(136,22): error TS2540: Cannot assign to 'id' because it is a read-only property.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(137,10): error TS2339: Property 'updatePart' does not exist on type 'DeepReadonlyObject<Part>'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(159,5): error TS2322: Type 'ZeroOf<T>' is not assignable to type 'T'.
'ZeroOf<T>' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'string | number'.
Type '0 | (T extends string ? "" : false)' is not assignable to type 'T'.
Type '0' is not assignable to type 'T'.
'0' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'string | number'.
Type '"" | 0' is not assignable to type 'T'.
'"" | 0' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'string | number'.
Type '""' is not assignable to type 'T'.
'""' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'string | number'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(160,5): error TS2322: Type 'T' is not assignable to type 'ZeroOf<T>'.
Type 'string | number' is not assignable to type 'ZeroOf<T>'.
Type 'string' is not assignable to type 'ZeroOf<T>'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(263,9): error TS2403: Subsequent variable declarations must have the same type. Variable 'z' must be of type 'T1', but here has type 'Foo<T & U>'.
tests/cases/conformance/types/conditional/conditionalTypes1.ts(288,43): error TS2322: Type 'T95<U>' is not assignable to type 'T94<U>'.
Type 'boolean' is not assignable to type 'true'.
==== tests/cases/conformance/types/conditional/conditionalTypes1.ts (22 errors) ====
type T00 = Exclude<"a" | "b" | "c" | "d", "a" | "c" | "f">; // "b" | "d"
type T01 = Extract<"a" | "b" | "c" | "d", "a" | "c" | "f">; // "a" | "c"
type T02 = Exclude<string | number | (() => void), Function>; // string | number
type T03 = Extract<string | number | (() => void), Function>; // () => void
type T04 = NonNullable<string | number | undefined>; // string | number
type T05 = NonNullable<(() => string) | string[] | null | undefined>; // (() => string) | string[]
function f1<T>(x: T, y: NonNullable<T>) {
x = y;
y = x; // Error
~
!!! error TS2322: Type 'T' is not assignable to type 'NonNullable<T>'.
}
function f2<T extends string | undefined>(x: T, y: NonNullable<T>) {
x = y;
y = x; // Error
~
!!! error TS2322: Type 'T' is not assignable to type 'NonNullable<T>'.
!!! error TS2322: Type 'string | undefined' is not assignable to type 'NonNullable<T>'.
!!! error TS2322: Type 'undefined' is not assignable to type 'NonNullable<T>'.
let s1: string = x; // Error
~~
!!! error TS2322: Type 'T' is not assignable to type 'string'.
!!! error TS2322: Type 'string | undefined' is not assignable to type 'string'.
!!! error TS2322: Type 'undefined' is not assignable to type 'string'.
let s2: string = y;
}
function f3<T>(x: Partial<T>[keyof T], y: NonNullable<Partial<T>[keyof T]>) {
x = y;
y = x; // Error
~
!!! error TS2322: Type 'T[keyof T] | undefined' is not assignable to type 'NonNullable<Partial<T>[keyof T]>'.
!!! error TS2322: Type 'undefined' is not assignable to type 'NonNullable<Partial<T>[keyof T]>'.
}
function f4<T extends { x: string | undefined }>(x: T["x"], y: NonNullable<T["x"]>) {
x = y;
y = x; // Error
~
!!! error TS2322: Type 'T["x"]' is not assignable to type 'NonNullable<T["x"]>'.
!!! error TS2322: Type 'string | undefined' is not assignable to type 'NonNullable<T["x"]>'.
!!! error TS2322: Type 'undefined' is not assignable to type 'NonNullable<T["x"]>'.
let s1: string = x; // Error
~~
!!! error TS2322: Type 'T["x"]' is not assignable to type 'string'.
!!! error TS2322: Type 'string | undefined' is not assignable to type 'string'.
!!! error TS2322: Type 'undefined' is not assignable to type 'string'.
let s2: string = y;
}
type Options = { k: "a", a: number } | { k: "b", b: string } | { k: "c", c: boolean };
type T10 = Exclude<Options, { k: "a" | "b" }>; // { k: "c", c: boolean }
type T11 = Extract<Options, { k: "a" | "b" }>; // { k: "a", a: number } | { k: "b", b: string }
type T12 = Exclude<Options, { k: "a" } | { k: "b" }>; // { k: "c", c: boolean }
type T13 = Extract<Options, { k: "a" } | { k: "b" }>; // { k: "a", a: number } | { k: "b", b: string }
type T14 = Exclude<Options, { q: "a" }>; // Options
type T15 = Extract<Options, { q: "a" }>; // never
declare function f5<T extends Options, K extends string>(p: K): Extract<T, { k: K }>;
let x0 = f5("a"); // { k: "a", a: number }
type OptionsOfKind<K extends Options["k"]> = Extract<Options, { k: K }>;
type T16 = OptionsOfKind<"a" | "b">; // { k: "a", a: number } | { k: "b", b: string }
type Select<T, K extends keyof T, V extends T[K]> = Extract<T, { [P in K]: V }>;
type T17 = Select<Options, "k", "a" | "b">; // // { k: "a", a: number } | { k: "b", b: string }
type TypeName<T> =
T extends string ? "string" :
T extends number ? "number" :
T extends boolean ? "boolean" :
T extends undefined ? "undefined" :
T extends Function ? "function" :
"object";
type T20 = TypeName<string | (() => void)>; // "string" | "function"
type T21 = TypeName<any>; // "string" | "number" | "boolean" | "undefined" | "function" | "object"
type T22 = TypeName<never>; // never
type T23 = TypeName<{}>; // "object"
type KnockoutObservable<T> = { object: T };
type KnockoutObservableArray<T> = { array: T };
type KnockedOut<T> = T extends any[] ? KnockoutObservableArray<T[number]> : KnockoutObservable<T>;
type KnockedOutObj<T> = {
[P in keyof T]: KnockedOut<T[P]>;
}
interface Item {
id: number;
name: string;
subitems: string[];
}
type KOItem = KnockedOutObj<Item>;
interface Part {
id: number;
name: string;
subparts: Part[];
updatePart(newName: string): void;
}
type FunctionPropertyNames<T> = { [K in keyof T]: T[K] extends Function ? K : never }[keyof T];
type FunctionProperties<T> = Pick<T, FunctionPropertyNames<T>>;
type NonFunctionPropertyNames<T> = { [K in keyof T]: T[K] extends Function ? never : K }[keyof T];
type NonFunctionProperties<T> = Pick<T, NonFunctionPropertyNames<T>>;
type T30 = FunctionProperties<Part>;
type T31 = NonFunctionProperties<Part>;
function f7<T>(x: T, y: FunctionProperties<T>, z: NonFunctionProperties<T>) {
x = y; // Error
~
!!! error TS2322: Type 'Pick<T, { [K in keyof T]: T[K] extends Function ? K : never; }[keyof T]>' is not assignable to type 'T'.
!!! error TS2322: 'Pick<T, { [K in keyof T]: T[K] extends Function ? K : never; }[keyof T]>' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint '{}'.
x = z; // Error
~
!!! error TS2322: Type 'Pick<T, { [K in keyof T]: T[K] extends Function ? never : K; }[keyof T]>' is not assignable to type 'T'.
!!! error TS2322: 'Pick<T, { [K in keyof T]: T[K] extends Function ? never : K; }[keyof T]>' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint '{}'.
y = x;
y = z; // Error
~
!!! error TS2322: Type 'Pick<T, { [K in keyof T]: T[K] extends Function ? never : K; }[keyof T]>' is not assignable to type 'Pick<T, { [K in keyof T]: T[K] extends Function ? K : never; }[keyof T]>'.
!!! error TS2322: Type 'T[keyof T] extends Function ? keyof T : never' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
z = x;
z = y; // Error
~
!!! error TS2322: Type 'Pick<T, { [K in keyof T]: T[K] extends Function ? K : never; }[keyof T]>' is not assignable to type 'Pick<T, { [K in keyof T]: T[K] extends Function ? never : K; }[keyof T]>'.
!!! error TS2322: Type 'T[keyof T] extends Function ? never : keyof T' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
}
function f8<T>(x: keyof T, y: FunctionPropertyNames<T>, z: NonFunctionPropertyNames<T>) {
x = y;
x = z;
y = x; // Error
~
!!! error TS2322: Type 'keyof T' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
!!! error TS2322: Type 'string | number | symbol' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
!!! error TS2322: Type 'string' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
y = z; // Error
~
!!! error TS2322: Type 'T[keyof T] extends Function ? never : keyof T' is not assignable to type 'T[keyof T] extends Function ? keyof T : never'.
!!! error TS2322: Type 'keyof T' is not assignable to type 'never'.
!!! error TS2322: Type 'string | number | symbol' is not assignable to type 'never'.
!!! error TS2322: Type 'string' is not assignable to type 'never'.
z = x; // Error
~
!!! error TS2322: Type 'keyof T' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
!!! error TS2322: Type 'string | number | symbol' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
!!! error TS2322: Type 'string' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
z = y; // Error
~
!!! error TS2322: Type 'T[keyof T] extends Function ? keyof T : never' is not assignable to type 'T[keyof T] extends Function ? never : keyof T'.
!!! error TS2322: Type 'keyof T' is not assignable to type 'never'.
}
type DeepReadonly<T> =
T extends any[] ? DeepReadonlyArray<T[number]> :
T extends object ? DeepReadonlyObject<T> :
T;
interface DeepReadonlyArray<T> extends ReadonlyArray<DeepReadonly<T>> {}
type DeepReadonlyObject<T> = {
readonly [P in NonFunctionPropertyNames<T>]: DeepReadonly<T[P]>;
};
function f10(part: DeepReadonly<Part>) {
let name: string = part.name;
let id: number = part.subparts[0].id;
part.id = part.id; // Error
~~
!!! error TS2540: Cannot assign to 'id' because it is a read-only property.
part.subparts[0] = part.subparts[0]; // Error
~~~~~~~~~~~~~~~~
!!! error TS2542: Index signature in type 'DeepReadonlyArray<Part>' only permits reading.
part.subparts[0].id = part.subparts[0].id; // Error
~~
!!! error TS2540: Cannot assign to 'id' because it is a read-only property.
part.updatePart("hello"); // Error
~~~~~~~~~~
!!! error TS2339: Property 'updatePart' does not exist on type 'DeepReadonlyObject<Part>'.
}
type ZeroOf<T extends number | string | boolean> = T extends number ? 0 : T extends string ? "" : false;
function zeroOf<T extends number | string | boolean>(value: T) {
return <ZeroOf<T>>(typeof value === "number" ? 0 : typeof value === "string" ? "" : false);
}
function f20<T extends string>(n: number, b: boolean, x: number | boolean, y: T) {
zeroOf(5); // 0
zeroOf("hello"); // ""
zeroOf(true); // false
zeroOf(n); // 0
zeroOf(b); // False
zeroOf(x); // 0 | false
zeroOf(y); // ZeroOf<T>
}
function f21<T extends number | string>(x: T, y: ZeroOf<T>) {
let z1: number | string = y;
let z2: 0 | "" = y;
x = y; // Error
~
!!! error TS2322: Type 'ZeroOf<T>' is not assignable to type 'T'.
!!! error TS2322: 'ZeroOf<T>' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'string | number'.
!!! error TS2322: Type '0 | (T extends string ? "" : false)' is not assignable to type 'T'.
!!! error TS2322: Type '0' is not assignable to type 'T'.
!!! error TS2322: '0' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'string | number'.
!!! error TS2322: Type '"" | 0' is not assignable to type 'T'.
!!! error TS2322: '"" | 0' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'string | number'.
!!! error TS2322: Type '""' is not assignable to type 'T'.
!!! error TS2322: '""' is assignable to the constraint of type 'T', but 'T' could be instantiated with a different subtype of constraint 'string | number'.
y = x; // Error
~
!!! error TS2322: Type 'T' is not assignable to type 'ZeroOf<T>'.
!!! error TS2322: Type 'string | number' is not assignable to type 'ZeroOf<T>'.
!!! error TS2322: Type 'string' is not assignable to type 'ZeroOf<T>'.
}
type T35<T extends { a: string, b: number }> = T[];
type T36<T> = T extends { a: string } ? T extends { b: number } ? T35<T> : never : never;
type T37<T> = T extends { b: number } ? T extends { a: string } ? T35<T> : never : never;
type T38<T> = [T] extends [{ a: string }] ? [T] extends [{ b: number }] ? T35<T> : never : never;
type Extends<T, U> = T extends U ? true : false;
type If<C extends boolean, T, F> = C extends true ? T : F;
type Not<C extends boolean> = If<C, false, true>;
type And<A extends boolean, B extends boolean> = If<A, B, false>;
type Or<A extends boolean, B extends boolean> = If<A, true, B>;
type IsString<T> = Extends<T, string>;
type Q1 = IsString<number>; // false
type Q2 = IsString<"abc">; // true
type Q3 = IsString<any>; // boolean
type Q4 = IsString<never>; // never
type N1 = Not<false>; // true
type N2 = Not<true>; // false
type N3 = Not<boolean>; // boolean
type A1 = And<false, false>; // false
type A2 = And<false, true>; // false
type A3 = And<true, false>; // false
type A4 = And<true, true>; // true
type A5 = And<boolean, false>; // false
type A6 = And<false, boolean>; // false
type A7 = And<boolean, true>; // boolean
type A8 = And<true, boolean>; // boolean
type A9 = And<boolean, boolean>; // boolean
type O1 = Or<false, false>; // false
type O2 = Or<false, true>; // true
type O3 = Or<true, false>; // true
type O4 = Or<true, true>; // true
type O5 = Or<boolean, false>; // boolean
type O6 = Or<false, boolean>; // boolean
type O7 = Or<boolean, true>; // true
type O8 = Or<true, boolean>; // true
type O9 = Or<boolean, boolean>; // boolean
type T40 = never extends never ? true : false; // true
type T41 = number extends never ? true : false; // false
type T42 = never extends number ? true : false; // true
type IsNever<T> = [T] extends [never] ? true : false;
type T50 = IsNever<never>; // true
type T51 = IsNever<number>; // false
type T52 = IsNever<any>; // false
function f22<T>(x: T extends (infer U)[] ? U[] : never) {
let e = x[0]; // {}
}
function f23<T extends string[]>(x: T extends (infer U)[] ? U[] : never) {
let e = x[0]; // string
}
// Repros from #21664
type Eq<T, U> = T extends U ? U extends T ? true : false : false;
type T60 = Eq<true, true>; // true
type T61 = Eq<true, false>; // false
type T62 = Eq<false, true>; // false
type T63 = Eq<false, false>; // true
type Eq1<T, U> = Eq<T, U> extends false ? false : true;
type T70 = Eq1<true, true>; // true
type T71 = Eq1<true, false>; // false
type T72 = Eq1<false, true>; // false
type T73 = Eq1<false, false>; // true
type Eq2<T, U> = Eq<T, U> extends true ? true : false;
type T80 = Eq2<true, true>; // true
type T81 = Eq2<true, false>; // false
type T82 = Eq2<false, true>; // false
type T83 = Eq2<false, false>; // true
// Repro from #21756
type Foo<T> = T extends string ? boolean : number;
type Bar<T> = T extends string ? boolean : number;
const convert = <U>(value: Foo<U>): Bar<U> => value;
type Baz<T> = Foo<T>;
const convert2 = <T>(value: Foo<T>): Baz<T> => value;
function f31<T>() {
type T1 = T extends string ? boolean : number;
type T2 = T extends string ? boolean : number;
var x: T1;
var x: T2;
}
function f32<T, U>() {
type T1 = T & U extends string ? boolean : number;
type T2 = Foo<T & U>;
var z: T1;
var z: T2; // Error, T2 is distributive, T1 isn't
~
!!! error TS2403: Subsequent variable declarations must have the same type. Variable 'z' must be of type 'T1', but here has type 'Foo<T & U>'.
!!! related TS6203 tests/cases/conformance/types/conditional/conditionalTypes1.ts:262:9: 'z' was also declared here.
}
function f33<T, U>() {
type T1 = Foo<T & U>;
type T2 = Bar<T & U>;
var z: T1;
var z: T2;
}
// Repro from #21823
type T90<T> = T extends 0 ? 0 : () => 0;
type T91<T> = T extends 0 ? 0 : () => 0;
const f40 = <U>(a: T90<U>): T91<U> => a;
const f41 = <U>(a: T91<U>): T90<U> => a;
type T92<T> = T extends () => 0 ? () => 1 : () => 2;
type T93<T> = T extends () => 0 ? () => 1 : () => 2;
const f42 = <U>(a: T92<U>): T93<U> => a;
const f43 = <U>(a: T93<U>): T92<U> => a;
type T94<T> = T extends string ? true : 42;
type T95<T> = T extends string ? boolean : number;
const f44 = <U>(value: T94<U>): T95<U> => value;
const f45 = <U>(value: T95<U>): T94<U> => value; // Error
~~~~~
!!! error TS2322: Type 'T95<U>' is not assignable to type 'T94<U>'.
!!! error TS2322: Type 'boolean' is not assignable to type 'true'.
// Repro from #21863
function f50() {
type Eq<T, U> = T extends U ? U extends T ? true : false : false;
type If<S, T, U> = S extends false ? U : T;
type Omit<T extends object> = { [P in keyof T]: If<Eq<T[P], never>, never, P>; }[keyof T];
type Omit2<T extends object, U = never> = { [P in keyof T]: If<Eq<T[P], U>, never, P>; }[keyof T];
type A = Omit<{ a: void; b: never; }>; // 'a'
type B = Omit2<{ a: void; b: never; }>; // 'a'
}
// Repro from #21862
type OldDiff<T extends keyof any, U extends keyof any> = (
& { [P in T]: P; }
& { [P in U]: never; }
& { [x: string]: never; }
)[T];
type NewDiff<T, U> = T extends U ? never : T;
interface A {
a: 'a';
}
interface B1 extends A {
b: 'b';
c: OldDiff<keyof this, keyof A>;
}
interface B2 extends A {
b: 'b';
c: NewDiff<keyof this, keyof A>;
}
type c1 = B1['c']; // 'c' | 'b'
type c2 = B2['c']; // 'c' | 'b'
// Repro from #21929
type NonFooKeys1<T extends object> = OldDiff<keyof T, 'foo'>;
type NonFooKeys2<T extends object> = Exclude<keyof T, 'foo'>;
type Test1 = NonFooKeys1<{foo: 1, bar: 2, baz: 3}>; // "bar" | "baz"
type Test2 = NonFooKeys2<{foo: 1, bar: 2, baz: 3}>; // "bar" | "baz"
// Repro from #21729
interface Foo2 { foo: string; }
interface Bar2 { bar: string; }
type FooBar = Foo2 | Bar2;
declare interface ExtractFooBar<FB extends FooBar> { }
type Extracted<Struct> = {
[K in keyof Struct]: Struct[K] extends FooBar ? ExtractFooBar<Struct[K]> : Struct[K];
}
// Repro from #22985
type RecursivePartial<T> = {
[P in keyof T]?: T[P] extends Array<any> ? {[index: number]: RecursivePartial<T[P][0]>} :
T[P] extends object ? RecursivePartial<T[P]> : T[P];
};
declare function assign<T>(o: T, a: RecursivePartial<T>): void;
var a = {o: 1, b: 2, c: [{a: 1, c: '213'}]}
assign(a, {o: 2, c: {0: {a: 2, c: '213123'}}})
// Repros from #23843
type Weird1 = (<U extends boolean>(a: U) => never) extends
(<U extends true>(a: U) => never) ? never : never;
type Weird2 = (<U extends boolean>(a: U) => U) extends
(<U extends true>(a: U) => infer T) ? T : never;