npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

jest-time-helpers

v0.1.1

Published

Helpers you can use in tests that relate to the passage of time (i.e. code that involves setTimeout, setInterval, new Date(), Date.now(), etc)

Downloads

1,080

Readme

jest-time-helpers

Helpers you can use in tests that relate to the passage of time (i.e. code that involves setTimeout, setInterval, new Date(), Date.now(), etc.). Allows you to "set the clock" to a particular point in time, advancing any setTimeout or setInterval calls that need advancing at the same time. Makes it possible (even pleasant!) to test code that would normally be dependent on the passage of time, such as scheduled events.

Documentation.

This helper library was born out of adding cron functionality to Graphile Worker and needing a reliable way to test it.

If you find this useful, please give it a star ⭐

Methods

For full documentation, please click the headers. The following acts as a quick-reference.

setupFakeTimers()

Import and call the setupFakeTimers helper at the top of your test file:

import { setupFakeTimers } from "jest-time-helpers";
const { setTime } = setupFakeTimers();

Then inside your tests you can call setTime(timestamp) to pretend that the system time is the timestamp you gave. When you set the timestamp to a value after the previous timestamp, all timers (setTimeout, setInterval, etc) will be advanced by that amount, as well as the "clock". When you set the timestamp to a value before the previous timestamp, only the clock will be updated and no timeouts/intervals will be effected.

Example:

const REFERENCE_TIMESTAMP = 950536800000; /* 14th February 2000, 2pm UTC */

test("new Date().toISOString() returns the expected timestamp", () => {
  setTime(REFERENCE_TIMESTAMP);
  // Note, time may have advanced a millisecond or two, so we can't be too precise
  expect(new Date().toISOString()).toMatch(/^2000-02-14T14:00:0.*Z$/);
});

sleep(ms: number)

A trivial method that returns a promise that resolves after the given number of real-time milliseconds. The important part about this method (as opposed to one that you might write yourself) is that it is not inhibited or influenced by fake timers.

sleepUntil(condition: () => void, maxDuration = 2000, pollInterval = 2)

Polls the condition callback every pollInterval milliseconds, and resolves success when condition() returns a truthy value. If maxDuration elapses before condition() returns true, returns a rejected promise.

Useful for waiting on external actions without putting arbitrary sleeps in your code (e.g. waiting for a database record to be created).

Like sleep(), it is not inhibited or influenced by fake timers.

Constants

  • SECOND - number of milliseconds in a second
  • MINUTE - number of milliseconds in a minute
  • HOUR - number of milliseconds in a hour
  • DAY - number of milliseconds in a day
  • WEEK - number of milliseconds in a week

Crowd-funded open-source software

To help us develop software sustainably under the MIT license, we ask all individuals and businesses that use our software to help support its ongoing maintenance and development via sponsorship.

Click here to find out more about sponsors and sponsorship.

Development

Checkout the repository, then run the following commands:

yarn
yarn test