chronokinesis

 

Mock time and date for traveling and freezing. Inspired and borrowed from timekeeper.

- Introduction
- API Reference
- [freeze([...args])](#freezeargs)
- [travel([...args])](#travelargs)
- defrost()
- reset()
- isKeepingTime()
- [timezone(timeZone[, ...args])](#timezonetimezone-args)
- new TimeZoneTraveller(timeZone)
- [timezone.freeze([...args])](#timezonefreezeargs)
- [timezone.travel([...args])](#timezonetravelargs)
- timezone.reset()
- timezone.defrost()
- Distributions
- Nodejs require
- Browser (UMD)
- Acknowledgements

Introduction

Mock Date and Date.now in order to help you test time-dependent code. Provides travel, freeze, and timezone functionality for your Node.js tests.

``javascript
import * as ck from 'chronokinesis';

ck.freeze();

setTimeout(() => {
// Frozen
console.log(new Date());

ck.reset();
}, 2000);
`

With arguments:

`javascript
import * as ck from 'chronokinesis';
import assert from 'node:assert';

ck.freeze(1980, 0, 1);

assert.equal(true, ck.isKeepingTime());
assert.deepEqual(new Date(), new Date(1980, 0, 1));

ck.reset();
`

or use with luxon:

`javascript
import { DateTime } from 'luxon';
import * as ck from 'chronokinesis';

ck.travel(DateTime.now().plus({ year: 1 }).toMillis());

setTimeout(() => {
console.log('Traveled with Luxon DateTime one year and some', new Date());

ck.reset();
}, 2000);
`

or use with moment:

`javascript
import moment from 'moment';
import * as ck from 'chronokinesis';

ck.travel(moment().add(1, 'year'));

setTimeout(() => {
console.log('Traveled with Moment Date one year and some', new Date());

ck.reset();
}, 2000);
`

API Reference

freeze([...args])

Freeze point in time. Calls can be made with the same arguments as the Date constructor.

- ...args: Optional date constructor arguments, if empty stops time at now

`javascript
import * as ck from 'chronokinesis';

ck.freeze('1942-01-08');

setTimeout(() => {
// Frozen
console.log(new Date());

ck.reset();
}, 2000);
`

travel([...args])

Time travel to another era. Calls can be made with the same arguments as the Date constructor

- ...args: Optional date constructor arguments, pretty useless if empty but won´t crash

`javascript
import * as ck from 'chronokinesis';
let date = new Date(2018, 0, 31);

ck.travel(date);

setTimeout(function () {
console.log(new Date());
ck.reset();
}, 1500);
`

When used in combination with freeze the time is still frozen but at the travelled time().

`javascript
import * as ck from 'chronokinesis';
import moment from 'moment';

let date = new Date(2018, 0, 31);

ck.freeze(date);

ck.travel(moment().add(1, 'year'));

setTimeout(function () {
console.log(Still frozen but one year ahead ${new Date()});

ck.reset();
}, 1500);
`

defrost()

Defrost a frozen point in time. Used in combination with travelling will start ticking the clock.

`javascript
import * as ck from 'chronokinesis';

ck.freeze(1980, 0, 1);

// Travel one year
ck.travel(1981, 1, 1);

// Start ticking
ck.defrost();

setTimeout(() => {
// Tick tack
console.log(new Date());

ck.reset();
}, 2000);
`

reset()

Resets Date to current glory.

`javascript
import * as ck from 'chronokinesis';

ck.freeze(2060, 0, 1);
console.log(end of time is reached at ${new Date()} according to Newton);

ck.reset();

// Today
console.log(new Date());
`

isKeepingTime()

Utility function to see if we still travel or freeze time.

`javascript
import * as ck from 'chronokinesis';

console.log(ck.isKeepingTime() ? 'Is' : 'Not', 'keeping time');
ck.travel(1893448800000);
console.log(ck.isKeepingTime() ? 'Is' : 'Not', 'keeping time');

ck.reset();
`

timezone(timeZone[, ...args])

Travel to time zone.

- timeZone: IANA time zone string
- ...args: Optional travel to date arguments

Returns TimeZoneTraveller api

`javascript
import * as ck from 'chronokinesis';

ck.reset();

const tz = ck.timezone('Asia/Shanghai');

console.log('Now in Shanghai', new Date());

tz.freeze();

ck.reset();
`

new TimeZoneTraveller(timeZone)

Time zone traveller api.

`javascript
import { TimeZoneTraveller, reset } from 'chronokinesis';

const timezone = new TimeZoneTraveller('Asia/Shanghai');

timezone.freeze();

reset();
`

$3

Freeze at the specific timezone.

$3

Start traveling in the specific timezone.

$3

Same as #reset

$3

Same as #defrost

Distributions

The module is prepared for browser and nodejs.

Nodejs require

`js
const ck = require('chronokinesis');
`

Browser (UMD)

Use dist/chronokinesis.cjs. Sets global property chronokinesis`.

Acknowledgements

chronokinesis initial code is inspired and borrowed from timekeeper