Type Alias WritableKeysOf<T>

WritableKeysOf: NonNullable<
    {
        [P in keyof T]: IsEqual<
            { [Q in P]: T[P] },
            { readonly [Q in P]: T[P] },
        > extends false
            ? P
            : never
    }[keyof T],
>

Extract all writable keys from the given type.

This is useful when you want to create a new type that contains writable keys only.

Type Parameters

  • T

Example

import type {WritableKeysOf} from 'type-fest';

interface User {
	name: string;
	surname: string;
	readonly id: number;
}

type UpdateRequest<Entity extends object> = Pick<Entity, WritableKeysOf<Entity>>;

const update1: UpdateRequest<User> = {
	name: 'Alice',
	surname: 'Acme',
};

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