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tests/cases/conformance/types/mapped/recursiveMappedTypes.ts(3,6): error TS2456: Type alias 'Recurse' circularly references itself.
tests/cases/conformance/types/mapped/recursiveMappedTypes.ts(4,11): error TS2313: Type parameter 'K' has a circular constraint.
tests/cases/conformance/types/mapped/recursiveMappedTypes.ts(7,6): error TS2456: Type alias 'Recurse1' circularly references itself.
tests/cases/conformance/types/mapped/recursiveMappedTypes.ts(8,11): error TS2313: Type parameter 'K' has a circular constraint.
tests/cases/conformance/types/mapped/recursiveMappedTypes.ts(11,6): error TS2456: Type alias 'Recurse2' circularly references itself.
tests/cases/conformance/types/mapped/recursiveMappedTypes.ts(12,11): error TS2313: Type parameter 'K' has a circular constraint.
tests/cases/conformance/types/mapped/recursiveMappedTypes.ts(20,19): error TS2589: Type instantiation is excessively deep and possibly infinite.
tests/cases/conformance/types/mapped/recursiveMappedTypes.ts(73,5): error TS2502: '"each"' is referenced directly or indirectly in its own type annotation.
tests/cases/conformance/types/mapped/recursiveMappedTypes.ts(73,13): error TS2615: Type of property '"each"' circularly references itself in mapped type '{ [P in keyof ListWidget]: undefined extends ListWidget[P] ? never : P; }'.
==== tests/cases/conformance/types/mapped/recursiveMappedTypes.ts (9 errors) ====
// Recursive mapped types simply appear empty
type Recurse = {
~~~~~~~
!!! error TS2456: Type alias 'Recurse' circularly references itself.
[K in keyof Recurse]: Recurse[K]
~~~~~~~~~~~~~
!!! error TS2313: Type parameter 'K' has a circular constraint.
}
type Recurse1 = {
~~~~~~~~
!!! error TS2456: Type alias 'Recurse1' circularly references itself.
[K in keyof Recurse2]: Recurse2[K]
~~~~~~~~~~~~~~
!!! error TS2313: Type parameter 'K' has a circular constraint.
}
type Recurse2 = {
~~~~~~~~
!!! error TS2456: Type alias 'Recurse2' circularly references itself.
[K in keyof Recurse1]: Recurse1[K]
~~~~~~~~~~~~~~
!!! error TS2313: Type parameter 'K' has a circular constraint.
!!! related TS2751 tests/cases/conformance/types/mapped/recursiveMappedTypes.ts:8:17: Circularity originates in type at this location.
}
// Repro from #27881
export type Circular<T> = {[P in keyof T]: Circular<T>};
type tup = [number, number, number, number];
function foo(arg: Circular<tup>): tup {
~~~~~~~~~~~~~
!!! error TS2589: Type instantiation is excessively deep and possibly infinite.
return arg;
}
// Repro from #29442
type DeepMap<T extends unknown[], R> = {
[K in keyof T]: T[K] extends unknown[] ? DeepMap<T[K], R> : R;
};
type tpl = [string, [string, [string]]];
type arr = string[][];
type t1 = DeepMap<tpl, number>; // [number, [number, [number]]]
type t2 = DeepMap<arr, number>; // number[][]
// Repro from #29577
type Transform<T> = { [K in keyof T]: Transform<T[K]> };
interface User {
avatar: string;
}
interface Guest {
displayName: string;
}
interface Product {
users: (User | Guest)[];
}
declare var product: Transform<Product>;
product.users; // (Transform<User> | Transform<Guest>)[]
// Repro from #29702
type Remap1<T> = { [P in keyof T]: Remap1<T[P]>; };
type Remap2<T> = T extends object ? { [P in keyof T]: Remap2<T[P]>; } : T;
type a = Remap1<string[]>; // string[]
type b = Remap2<string[]>; // string[]
// Repro from #29992
type NonOptionalKeys<T> = { [P in keyof T]: undefined extends T[P] ? never : P }[keyof T];
type Child<T> = { [P in NonOptionalKeys<T>]: T[P] }
export interface ListWidget {
"type": "list",
"minimum_count": number,
"maximum_count": number,
"collapsable"?: boolean, //default to false, means all expanded
"each": Child<ListWidget>;
~~~~~~
!!! error TS2502: '"each"' is referenced directly or indirectly in its own type annotation.
~~~~~~~~~~~~~~~~~
!!! error TS2615: Type of property '"each"' circularly references itself in mapped type '{ [P in keyof ListWidget]: undefined extends ListWidget[P] ? never : P; }'.
}
type ListChild = Child<ListWidget>
declare let x: ListChild;
x.type;
// Repros from #41790
export type TV<T, K extends keyof T> = T[K] extends Record<infer E, any> ? E : never;
export type ObjectOrArray<T, K extends keyof any = keyof any> = T[] | Record<K, T | Record<K, T> | T[]>;
export type ThemeValue<K extends keyof ThemeType, ThemeType, TVal = any> =
ThemeType[K] extends TVal[] ? number :
ThemeType[K] extends Record<infer E, TVal> ? E :
ThemeType[K] extends ObjectOrArray<infer F> ? F : never;
export type Foo<T> = T extends { [P in infer E]: any } ? E : never;
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