https://github.com/guidesmiths/groundhog-day

An injectable clock for time based tests
https://github.com/guidesmiths/groundhog-day

Last synced: about 1 month ago
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An injectable clock for time based tests

• Host: GitHub
• URL: https://github.com/guidesmiths/groundhog-day
• Owner: guidesmiths
• Created: 2016-07-26T20:11:42.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2018-10-07T10:31:49.000Z (over 6 years ago)
• Last Synced: 2024-12-18T09:45:21.343Z (about 1 month ago)
• Language: JavaScript
• Size: 28.3 KB
• Stars: 1
• Watchers: 13
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md

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README

        
# groundhog-day

groundhog-day is a wrapper around ```Date.now()``` with real and fake implementations. The real implementation returns the current time, the fake implementation returns a fixed time (defaults to Groundhog day). Use the real implementation in your production code, but inject the fake implementation in tests for predictable results.

[![NPM version](https://img.shields.io/npm/v/groundhog-day.svg?style=flat-square)](https://www.npmjs.com/package/groundhog-day)

[![NPM downloads](https://img.shields.io/npm/dm/groundhog-day.svg?style=flat-square)](https://www.npmjs.com/package/groundhog-day)

[![Node.js CI](https://github.com/guidesmiths/groundhog-day/workflows/Node.js%20CI/badge.svg)](https://github.com/guidesmiths/groundhog-day/actions?query=workflow%3A%22Node.js+CI%22)

[![Code Climate](https://codeclimate.com/github/guidesmiths/groundhog-day/badges/gpa.svg)](https://codeclimate.com/github/guidesmiths/groundhog-day)

[![Test Coverage](https://codeclimate.com/github/guidesmiths/groundhog-day/badges/coverage.svg)](https://codeclimate.com/github/guidesmiths/groundhog-day/coverage)

## TL;DR

### 1. Use a fake clock in tests

```js

const { ok, equal } = require('assert');

const { fake: clock } = require('groundhog-day');

const request = require('request');

const Server = require('../server');

describe('Server', () => {

  let server

  before((done) => {

    server = new Server(clock);

    server.start(done);

  });

  after((done) => {

    server.stop(done);

  });

  it('should set last modified header', (done) => {

    request.get('http://localhost/demo', (err, res, body) => {

      ok(err);

      equal(res.headers['last-modified'], 'Tue, 2 Feb 2016 11:00:00 GMT');  // Groundhog Day

    })

  })

})

```

### 2. Use a real clock in production

```js

const Server = require('./server')

const { real: clock } = require('groundhog-day');

new Server(clock).start(err => {

  if (err) process.exit(1)

  console.log('Listening')

})

```

### Fixing Time

You can configure the fixed time returned by the fake clock in any of the following ways:

By specifying the number of milliseconds

```js

const { fake: clock } = require('groundhog-day');

clock.fix(1469563181761);

```

By specifying a date instance

```js

const { fake: clock } = require('groundhog-day');

clock.fix(new Date(1469563181761));

```

By specifying a date string

```js

const { fake: clock } = require('groundhog-day');

clock.fix(new Date('2016-07-26T19:59:41.761Z'))

```