index.js

'use strict';

const createAbortError = () => {
	const error = new Error('Delay aborted');
	error.name = 'AbortError';
	return error;
};

const createDelay = ({clearTimeout: defaultClear, setTimeout: set, willResolve}) => (ms, {value, signal} = {}) => {
	if (signal && signal.aborted) {
		return Promise.reject(createAbortError());
	}

	let timeoutId;
	let settle;
	let rejectFn;
	const clear = defaultClear || clearTimeout;

	const signalListener = () => {
		clear(timeoutId);
		rejectFn(createAbortError());
	};

	const cleanup = () => {
		if (signal) {
			signal.removeEventListener('abort', signalListener);
		}
	};

	const delayPromise = new Promise((resolve, reject) => {
		settle = () => {
			cleanup();
			if (willResolve) {
				resolve(value);
			} else {
				reject(value);
			}
		};

		rejectFn = reject;
		timeoutId = (set || setTimeout)(settle, ms);
	});

	if (signal) {
		signal.addEventListener('abort', signalListener, {once: true});
	}

	delayPromise.clear = () => {
		clear(timeoutId);
		timeoutId = null;
		cleanup();
		settle();
	};

	return delayPromise;
};

const delay = createDelay({willResolve: true});
delay.reject = createDelay({willResolve: false});
delay.createWithTimers = ({clearTimeout, setTimeout}) => {
	const delay = createDelay({clearTimeout, setTimeout, willResolve: true});
	delay.reject = createDelay({clearTimeout, setTimeout, willResolve: false});
	return delay;
};

module.exports = delay;
// TODO: Remove this for the next major release
module.exports.default = delay;