useEffect never called - Githubissues

trusktr commented 2 weeks ago

[ ] Check if updating to the latest Preact version resolves the issue

Describe the bug

I have this code:

/** @jsx h */
import { h, render } from 'preact';
import { useEffect } from 'preact/hooks';

function Container(props) {
  return <div style="width: 100%; height: 100%;">{props.children}</div>;
}

const App = () => {
  console.log('App');

  useEffect(() => {
    console.log('EFFECT !!!!!!!!!!!');
  }, []);

  return <Container></Container>;
};

render(<App />, document.body);

The hook is never called, the EFFECT log never happens.

Expected behavior

Isn't the effect supposed to run once?

Also the DOM content in the <body> is just <undefined>.

To Reproduce

https://stackblitz.com/edit/preact-starter-template-jzkt7e?file=App.jsx

(Heads up, this is a fork of the stackblitz that is the number one result for "stackblitz preact" on Google)

trusktr commented 2 weeks ago

Don't know why that one doesn't work, but this one works:

https://stackblitz.com/edit/create-preact-starter-kak5bf?file=src%2Findex.jsx

(this one is forked from a result I found lower in the search results.)