ES6 Promise.delay

delay-promise.js

module.exports = function(duration) {
	return function(){
		return new Promise(function(resolve, reject){
			setTimeout(function(){
				resolve();
			}, duration)
		});
	};
};

// Usage:

var delayPromise = require("./delay-promise");

doThing()
.then(...)
.then(delayPromise(5000))
.then(...)

@justml @jgerstle

I confirm that the following code works perfectly with Node.js:

const wait = require('util').promisify(setTimeout);

(async () => {
    console.log('Wait...');
    await wait(1000);
    console.log('...a second.');
})();

Hello future self, here's the TypeScript version for your copy/pasting pleasure:

const delay = (ms: number) => new Promise(_ => setTimeout(_, ms))

and my favorite JS version:

const delay = ms => new Promise(_ => setTimeout(_, ms))

You forget to clear the setTimeout

const delay = async <T>(timeout: number, value?: T) => {
    return new Promise((resolve) => {
        const timeoutId = setTimeout(() => {
            resolve(value);
            clearTimeout(timeoutId);
        }, timeout);
    });
};

@tolotrasmile That shouldn't be necessary, since this is a setTimeout, not a setInterval. A setTimeout only ever fires once, so once you're in the callback, there is nothing to clearTimeout anymore.

clearTimeout is basically just for cancelling a setTimeout that has not yet occurred.

For nodeJS only

import { setTimeout } from "timers/promises";

await setTimeout(3000, value);