---

🏃 Asynchronous side effects, without the nonsense.

useAsyncEffect(async () => {
  await doSomethingAsync();
});

Installation

npm install use-async-effect

or

yarn add use-async-effect

This package ships with TypeScript and Flow types.

API

The API is the same as React's useEffect(), except for some notable differences:

• The destroy function is passed as an optional second argument:

useAsyncEffect(callback, dependencies?);
useAsyncEffect(callback, onDestroy, dependencies?);

• The async callback will receive a single function to check whether the callback is still mounted:

useAsyncEffect(async isMounted => {
  const data1 = await fn1();
  if (!isMounted()) return;

  const data2 = await fn2();
  if (!isMounted()) return;

  doSomething(data1, data2);
});

Mounted means that it's running in the current component. It becomes unmounted if the component unmounts, or if the component is re-rendered and the callback is dropped and a new one is called.

Examples

Basic mount/unmount

useAsyncEffect(async () => console.log('mount'), () => console.log('unmount'), []);

Omitting destroy

useAsyncEffect(async () => console.log('mount'), []);

Handle effect result in destroy

useAsyncEffect(() => fetch('url'), (result) => console.log(result));

Making sure it's still mounted before updating component state

useAsyncEffect(async isMounted => {
  const data = await fetch(`/users/${id}`).then(res => res.json());
  if (!isMounted()) return;
  setUser(data);
}, [id]);

Linting dependencies list using ESLint

The react-hooks/exhaustive-deps rule allows you to check your custom hooks. From the Advanced Configuration options:

exhaustive-deps can be configured to validate dependencies of custom Hooks with the additionalHooks option. This option accepts a regex to match the names of custom Hooks that have dependencies.

‼️ Unfortunately, react-hooks/rules-of-hooks isn't configurable and the "Effect callbacks are synchronous to prevent race conditions. Put the async function inside" warning will be displayed.

{
  "rules": {
    // ...
    "react-hooks/exhaustive-deps": [
      "warn",
      {
        "additionalHooks": "(useAsyncEffect|useMyOtherCustomHook)"
      }
    ]
  }
}