Cancel that promise

Inspired by this article from React blog.

isMounted is an Antipattern

The primary use case for isMounted() is to avoid calling setState() after a component has unmounted, because calling setState() after a component has unmounted will emit a warning. The “setState warning” exists to help you catch bugs, because calling setState() on an unmounted component is an indication that your app/component has somehow failed to clean up properly. Specifically, calling setState() in an unmounted component means that your app is still holding a reference to the component after the component has been unmounted - which often indicates a memory leak!

Warning: Can only update a mounted or mounting component. This usually means you called setState, replaceState, or forceUpdate on an unmounted component. This is a no-op.

Usage

npm install cancel-that-promise

import makeCancelable from 'cancel-that-promise'

componentDidMount() {
  this.cancelFetch = makeCancelable(
    fetchResource(this.props.resource),
    fetched => this.setState(fetched),
    error => console.error(error)
  );
}
componentWillUnmount() {
  this.cancelFetch();
}

TODO

• write the README!