callable-promise

A tiny TypeScript utility for creating callable promises — promises that you can resolve simply by calling them like a function.

import { callablePromise } from "callable-promise";

const done = callablePromise<number>();

setTimeout(() => {
    done(42); // resolves the promise
}, 1000);

const result = await done; // 42

Features

• Promise that is also a function
• Fully typed (TypeScript generics)
• Zero dependencies
• Tracks internal state (pending / fulfilled)
• Simple and expressive API

Installation

npm install callable-promise

Usage

Create a callable promise

const ready = callablePromise<string>();

// resolve it later
ready("OK");

// await it anywhere
const value = await ready; // "OK"

Type-safe

const p = callablePromise<{ id: number }>();

p({ id: 123 });

const data = await p; // { id: number }

Check promise state

const done = callablePromise<number>();

console.log(done.state); // 0 (pending)

done(10);

console.log(done.state); // 1 (fulfilled)

API

callablePromise<T>()

Creates a hybrid object that is both:

• a Promise<T>
• a callable resolver function (value: T) => void

Type Definition

export type CallablePromise<T> = Promise<T> & {
    (value: T): void;
    readonly state: 0 | 1;
};

License

MIT