Awaitable type

A value that is returned directly or through a promise: the result of a callback that may be sync or async.

import type { Awaitable } from 'utils';

Signature

export type Awaitable<T> = PromiseLike<T> | T;

Parameters

Name	Description
T	The value type.

Example

type Loader = (page: number) => Awaitable<readonly Row[]>;

Tests

Line coverage: 0 %.

• ✅ accepts a value or a promise

Source

src/types/awaitable.ts (on GitHub)

Source code

/**
 * A value that is returned directly or through a promise: the result of a callback that may be sync or
 * async.
 *
 * @template T - The value type.
 * @example
 * type Loader = (page: number) => Awaitable<readonly Row[]>;
 */
export type Awaitable<T> = PromiseLike<T> | T;

Test file

import type { Awaitable } from './awaitable';

describe('Awaitable', () => {
  it('accepts a value or a promise', () => {
    expectTypeOf<number>().toExtend<Awaitable<number>>();
    expectTypeOf<Promise<number>>().toExtend<Awaitable<number>>();
    expectTypeOf<Promise<string>>().not.toExtend<Awaitable<number>>();
  });
});

Keywords: awaitable, types, type