async-janitor

Easily cancel callbacks for promises, timers, and observables ✨

Have you ever seen the following in your React app's logs?

Warning: Can't call setState (or forceUpdate) on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in the componentWillUnmount method.

Yeah it's pretty annoying. Here's a tool to help you mop up the mess.

Installation

$ npm install async-janitor

Usage

import Janitor from 'async-janitor';
 
class MyComponent extends React.Component {
  janitor = new Janitor();
 
  componentDidMount() {
    // delay a task
    this.janitor.setTimeout(this.timeoutCallback, 100);
 
    // fetch some stuff
    this.janitor.addPromise(fetchStuff())
      .then(this.doStuff);
 
    // add a subscription to a cool Rx.JS observable stream
    this.janitor.addStream(coolStream)
      .subscribe(this.doCoolThings);
 
    // add a handler for the 'scroll' event on the document
    this.janitor.addEventListener(document, 'scroll', this.handleScroll);
  }
 
  componentWillUnmount() {
    // Clears timeouts, cancels promises, disposes subscriptions, unbinds event handlers
    // that were created in componentDidMount()
    this.janitor.cleanup();
  }
}

Development

$ npm install --only=dev

• npm run clean - Remove lib/ directory
• npm test - Run tests with linting and coverage results.
• npm test:only - Run tests without linting or coverage.
• npm test:watch - You can even re-run tests on file changes!
• npm test:prod - Run tests with minified code.
• npm run test:examples - Test written examples on pure JS for better understanding module usage.
• npm run lint - Run ESlint with airbnb-config
• npm run cover - Get coverage report for your code.
• npm run build - Babel will transpile ES6 => ES5 and minify the code.
• npm run prepublish - Hook for npm. Do all the checks before publishing your module.

License

MIT © StyleSeat