RequireKeys type

Makes some optional properties required: the result of filling in defaults.

import type { RequireKeys } from 'utils';

Signature

export type RequireKeys<T, K extends keyof T> = Simplify<Omit<T, K> & Required<Pick<T, K>>>;

Parameters

Name	Description
T	The object type.
K	The keys to require.

Example

type ResolvedOptions = RequireKeys<Options, 'duration' | 'easing'>;

Tests

Line coverage: 0 %.

• ✅ requires the given keys only

Source

src/types/require-keys.ts (on GitHub)

Uses

• Simplify: Flattens intersections and mapped types into a plain object type, so that editor tooltips show the properties instead of A & Omit<B, 'c'>.

Files it needs

src/types/require-keys.ts imports, directly or not:

• src/types/simplify.ts

Source code

import type { Simplify } from './simplify';

/**
 * Makes some optional properties required: the result of filling in defaults.
 *
 * @template T - The object type.
 * @template K - The keys to require.
 * @example
 * type ResolvedOptions = RequireKeys<Options, 'duration' | 'easing'>;
 */
export type RequireKeys<T, K extends keyof T> = Simplify<Omit<T, K> & Required<Pick<T, K>>>;

Test file

import type { RequireKeys } from './require-keys';

describe('RequireKeys', () => {
  it('requires the given keys only', () => {
    expectTypeOf<RequireKeys<{ a?: number; b?: string }, 'a'>>().toEqualTypeOf<{ a: number; b?: string }>();
  });
});

Keywords: require, keys, types, type