isomorphic-timers-promises

What is isomorphic-timers-promises?

The isomorphic-timers-promises npm package provides a set of timer functions that return promises, making it easier to work with asynchronous code. It is designed to work in both Node.js and browser environments, hence the term 'isomorphic'.

What are isomorphic-timers-promises's main functionalities?

setTimeout

The setTimeout function returns a promise that resolves after a specified number of milliseconds. This is useful for delaying the execution of code.

const { setTimeout } = require('isomorphic-timers-promises');

setTimeout(1000).then(() => {
  console.log('1 second has passed');
});

setInterval

The setInterval function returns an interval ID and executes a callback function at specified intervals. The clearInterval function can be used to stop the interval.

const { setInterval, clearInterval } = require('isomorphic-timers-promises');

const intervalId = setInterval(1000, () => {
  console.log('1 second interval');
});

// To clear the interval after 5 seconds
setTimeout(5000).then(() => clearInterval(intervalId));

setImmediate

The setImmediate function returns a promise that resolves immediately after the current event loop, allowing you to execute code asynchronously without any delay.

const { setImmediate } = require('isomorphic-timers-promises');

setImmediate().then(() => {
  console.log('This runs immediately after the current event loop');
});

Other packages similar to isomorphic-timers-promises

timers-promises

The timers-promises package from Node.js provides similar functionality, offering promise-based versions of setTimeout, setInterval, and setImmediate. It is more tightly integrated with Node.js but lacks isomorphic support for browser environments.

delay

The delay package is a simple utility for delaying execution using promises. It primarily focuses on the setTimeout functionality and is widely used for creating delays in asynchronous code. However, it does not offer setInterval or setImmediate functionalities.

sleep-promise

The sleep-promise package provides a promise-based sleep function that pauses execution for a specified duration. It is similar to the setTimeout functionality in isomorphic-timers-promises but does not include setInterval or setImmediate.

README

isomorphic-timers-promises

timers/promises for client and server.

The timers/promises API provides an alternative set of timer functions that return Promise objects.

Install

npm install isomorphic-timers-promises --save

Usage

import {
	setTimeout,
	setImmediate,
	setInterval
} from 'isomorphic-timers-promises';

(async () => {
	const result = await setTimeout(100, 'becky');
	console.log(result); // 'becky'
})();

(async () => {
	const result = await setImmediate('maya');
	console.log(result); // 'maya'
})();

(async () => {
	let result = 0;
	for await (const startTime of setInterval(100, Date.now())) {
		const now = Date.now();
		result = result + 1;
		if (now - startTime >= 1000) {
			break;
		}
	}
	console.log(result); // 10
})();

Usage with Webpack

Show me

// webpack.config.js
module.exports = {
	// ...
	resolve: {
		alias: {
			'timers/promises': 'isomorphic-timers-promises'
		}
	}
};

Usage with Rollup

Show me

// rollup.config.js
const { default: resolve } = require('@rollup/plugin-node-resolve');
const alias = require('@rollup/plugin-alias');

module.exports = {
	// ...
	plugins: [
		resolve(),
		alias({
			entries: {
				'timers/promises': 'isomorphic-timers-promises'
			}
		})
	]
};

API

setTimeout([delay[, value[, options]]])

Returns: Promise

Property	Type	Default	Description
delay	number	1	The number of milliseconds to wait before fulfilling the promise.
value	*		A value with which the promise is fulfilled.
options.ref	boolean	true	Set to false to indicate that the scheduled timeout should not require the event loop to remain active. Valid only for server environment.
options.signal	AbortSignal		An optional AbortSignal that can be used to cancel the scheduled timeout.

setImmediate([value[, options]])

Returns: Promise

Property	Type	Default	Description
value	*		A value with which the promise is fulfilled.
options.ref	boolean	true	Set to false to indicate that the scheduled immediate should not require the event loop to remain active. Valid only for server environment.
options.signal	AbortSignal		An optional AbortSignal that can be used to cancel the scheduled immediate.

setInterval([delay[, value[, options]]])

Returns: async iterator that generates values in an interval of delay.

Property	Type	Default	Description
delay	number	1	The number of milliseconds to wait between iterations.
value	*		A value with which the iterator returns.
options.ref	boolean	true	Set to false to indicate that the scheduled timeout between iterations should not require the event loop to remain active. Valid only for server environment.
options.signal	AbortSignal		An optional AbortSignal that can be used to cancel the scheduled timeout between operations.

Node and browser support

Supports Node 10+.

Tested in Chrome 72, Firefox 65, Internet Explorer 11 and should work in all modern browsers.

Check support based on Browserslist configuration).

Assumes Promise, AbortController and setImmediate are polyfilled or available in global context.

Test

For automated tests, run npm run test:automated (append :watch for watcher support).

Test suite is taken and modified from official Node.js repository (setTimeout, setImmediate, setInterval).

License

MIT © Ivan Nikolić

Changelog

[1.0.1][] - 2021-06-30

Added

• Configuration for Node support