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

makecancelable

v1.1.1

Published

Yet another makeCancelable Promise wrapper

Downloads

3,473

Readme

makecancelable

CircleCI

Yet another makeCancelable Promise wrapper, inspired by this article from React blog.

Quickstart

Install from the command line:

npm install makecancelable

Import into the source code:

import makeCancelable from 'makecancelable';

Use to make a promise cancelable*:

// User interface:
const renderOpeningCrawl = ({ opening_crawl }) => console.log(opening_crawl);

// Target promise:
const downloadEpisodeIV = fetch(
  'https://swapi.co/api/films/1/?format=json'
).then(response => response.json());

// Make rendering opening crawl cancelable:
const cancel = makeCancelable(
  downloadEpisodeIV,
  renderOpeningCrawl,
  console.error
);

// Cancel rendering opening crawl if it doesn’t download in one second:
setTimeout(() => {
  console.log('Too late, young Luke Skywalker');
  cancel();
}, 1000);

* It’s worth mentioning that calling cancel doesn’t cancel fetching the resource. Instead, it cancels rendering opening crawl (and errors if any).

For complete specification, see makeCancellable.test.js.

Using in React components

For a good reason, updating the state of an unmounted React component can lead to the following error in the console:

setState(…): Can only update a mounted or mounting component.
This usually means you called setState() on an unmounted component. This is a no-op

A typical example would be requesting a remote API in componentDidMount and updating the state after the API has responded. The user’s actions can lead to unmounting of the component (e.g. navigating to another app’s page) before calling setState.

The correct way to fix this issue, according to the article, is to cancel any callbacks in componentWillUnmount, prior to unmounting.

Without makeCancelable:

componentDidMount() {
  getDataFromApi()
    .then(data => this.setState({ data }))
    .catch(console.error);
}
componentWillUnmount() {
  /* nothing to cancel */
}

With makeCancelable:

componentDidMount() {
  this.cancelRequest = makeCancelable(
    getDataFromApi(),
    data => this.setState({ data }),
    console.error
  );
}
componentWillUnmount() {
  this.cancelRequest();
}

Contributing

Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests.

Versioning

SemVer is used for versioning. For the versions available, see the tags on this repository.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Credits

  • @istarkov for original makeCancelable implementation here;
  • @jwbay for suggesting flushPromises here to use in tests.