time-fast-forward
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Fake the system time (Date, hrtime) in your tests, without freezing it (unlike in many other libraries). Freeze only when you need.
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# time-fast-forward
Control the system time (Date, hrtime) in your tests, without freezing it (unlike in many other libraries).
Mock date and time both in NodeJS and web applications. Supports typescript.
## Installation
```bash
npm install --save-dev time-fast-forward
```
## Examples
```ts
import { jumpToTime, shiftTimeBy, resetTime } from 'time-fast-forward';
console.log(new Date()); // -> Sat Sep 12 2020 01:18:21
// Add one hour to the current clock
shiftTimeBy(60 * 60 * 1000);
console.log(new Date()); // -> Sat Sep 12 2020 02:18:21
// Shift -2 hours from now (-1 hour from the original time in this example)
shiftTimeBy(-2 * 60 * 60 * 1000);
console.log(new Date()); // -> Sat Sep 12 2020 00:18:21
// Jump to a given date and time. Mind when providing anything relative here
jumpToTime("Fri, 11 Sep 2022 22:26:43 GMT"); // jumpToTime(2020, 1, 3), etc
console.log(new Date()); // -> Fri Sep 11 2022 22:26:43
resetTime(); // Get back to the normal time
console.log(new Date()); // -> Sat Sep 12 2020 01:18:21
```
This library can also potentially support time freezing, PRs for this are welcome:
```ts
console.log(new Date()); // -> Sat Sep 12 2020 01:18:21
// note seconds here ^
setTimeout(() => {
console.log(new Date()); // -> Sat Sep 12 2020 01:18:22
// time is still ticking ^
// Not implemented yet: PRs are welcome!
freezeTime();
setTimeout(() => {
console.log(new Date()); // -> Sat Sep 12 2020 01:18:22
// now time is frozen ^
// Not implemented yet: PRs are welcome!
unfreezeTime();
console.log(new Date()); // -> Sat Sep 12 2020 01:18:22
// now at +1s from real time ^
resetTime();
console.log(new Date()); // -> Sat Sep 12 2020 01:18:21
// back to the normal time! ^
}, 1000);
}, 1000);
```
## License
[MIT](LICENSE) © [Nikita Savchenko](https://nikita.tk)