Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Remove unnecessary useEffect and ref in usePrevious hook #2617

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
fix: remove unnecessary useEffect and ref in usePrevious hook
RickHuizing01 committed Dec 23, 2024

Verified

This commit was created on GitHub.com and signed with GitHub’s verified signature.
commit b684de5ce1bee600724ee97fedd7d037368651af
2 changes: 1 addition & 1 deletion docs/usePrevious.md
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
# `usePrevious`

React state hook that returns the previous state as described in the [React hooks FAQ](https://reactjs.org/docs/hooks-faq.html#how-to-get-the-previous-props-or-state).
React state hook that returns the previous state as described in [Adjusting some state when a prop changes](https://react.dev/learn/you-might-not-need-an-effect#adjusting-some-state-when-a-prop-changes).

## Usage

14 changes: 8 additions & 6 deletions src/usePrevious.ts
Original file line number Diff line number Diff line change
@@ -1,11 +1,13 @@
import { useEffect, useRef } from 'react';
import { useState } from 'react';

export default function usePrevious<T>(state: T): T | undefined {
const ref = useRef<T>();
const [current, setCurrent] = useState<T>(state);
const [previous, setPrevious] = useState<T>();

useEffect(() => {
ref.current = state;
});
if (current !== state) {
setCurrent(state);
setPrevious(current);
}

return ref.current;
return previous;
}