sleep-promise/README.md

Resolves a promise after a specified delay

# sleep-promise [![License][license-image]][license-url] [![NPM version][npm-image]][npm-url] [![NPM downloads][npm-downloads-image]][npm-downloads-url] [![Build][build-image]][build-url] [![Coverage][coverage-image]][coverage-url]

_sleep-promise_ resolves a promise after a specified delay.

## Installation

### node.js

    npm install sleep-promise

## Usage async / await

```javascript
import sleep from 'sleep-promise';

(async () => {
    await sleep(2000);
    console.log('2 seconds later …');
})();
```

## Usage ES5

```javascript
var sleep = require('sleep-promise');

sleep(2000).then(function() {
    console.log('2 seconds later …');
});
```

## Usage in a promise chain

```javascript
import sleep from 'sleep-promise';

let trace = value => {
    console.log(value);
    return value;
};

sleep(2000)
    .then(() => 'hello')
    .then(trace)
    .then(sleep(1000))
    .then(value => value + ' world')
    .then(trace)
    .then(sleep(500))
    .then(value => value + '!')
    .then(trace);

// [2 seconds sleep]
// hello
// [1 second sleep]
// hello world
// [500 ms sleep]
// hello world!
```

## Usage in a test file that mocks setTimeout

```javascript
import sinon from 'sinon';
import sleep from 'sleep-promise';

const clock = sinon.useFakeTimers();

(async () => {
    // 2 seconds faked by sinon
    const sleepPromise = sleep(2000);
    clock.tick(2000);
    await sleepPromise;
    console.log('instant');

    // Caches global setTimeout before sinon replaced it
    const sleepPromise2 = sleep(2000, { useCachedSetTimeout: true });
    clock.tick(2000);
    await sleepPromise2;
    console.log('2 seconds later');
})();
```

## License

[MIT](LICENSE.md)

[license-image]: https://img.shields.io/github/license/brummelte/sleep-promise.svg
[license-url]: https://github.com/brummelte/sleep-promise/blob/master/LICENSE.md
[npm-image]: https://img.shields.io/npm/v/sleep-promise.svg
[npm-url]: https://www.npmjs.com/package/sleep-promise
[npm-downloads-image]: https://img.shields.io/npm/dm/sleep-promise.svg
[npm-downloads-url]: https://www.npmjs.com/package/sleep-promise
[build-image]: https://img.shields.io/circleci/project/github/brummelte/sleep-promise/master.svg
[build-url]: https://circleci.com/gh/brummelte/sleep-promise
[coverage-image]: https://img.shields.io/coveralls/github/brummelte/sleep-promise/master.svg
[coverage-url]: https://coveralls.io/github/brummelte/sleep-promise?branch=master