webshrine / stdtyp/src / ReadonlyKeys

Type Alias: ReadonlyKeys<T>

ReadonlyKeys<T>: { [P in keyof T]-?: IfEquals<{ [Q in P]: T[P] }, { -readonly [Q in P]: T[P] }, never, P> }[keyof T]

ReadonlyKeys

Type Parameters

• T extends object

Desc

Get union type of keys that are readonly in object type T Credit: Matt McCutchen https://stackoverflow.com/questions/52443276/how-to-exclude-getter-only-properties-from-type-in-typescript

Example

type Props = { readonly foo: string; bar: number };

  // Expect: "foo"
  type Keys = ReadonlyKeys<Props>;

Defined in

node_modules/.pnpm/utility-types@3.11.0/node_modules/utility-types/dist/mapped-types.d.ts:113