Preact + antd creates memory leak

[ferretwithaberet]

• Check if updating to the latest Preact version resolves the issue

Describe the bug
Using Preact with the antd UI library causes a memory leak which, as far as I've tested, does not happen with React.

To Reproduce

1. Make a new Vite project with Preact.
2. Install antd.
3. Import and use components from antd. I've personally tested using Button.

Repro: https://github.com/ferretwithaberet/preact-antd-memleak

Expected behavior
Should not cause memory leak.

[rschristian]

To Reproduce

If possible, please provide a link to a StackBlitz/CodeSandbox/Codepen project or a GitHub repository that demonstrates the issue. You can use the following template on StackBlitz to get started: https://stackblitz.com/edit/create-preact-starter

The above cones from our issue template which I believe you've deleted & ignored. Please provide a reproduction as we've required.

[ferretwithaberet]

@rschristian Added repro link to the main post. Seems like the memory leak only happens when Button rerenders, that's why I've added that setInterval clock. I also made the reproducer render 700 buttons to make the memory leak more visible. I am not sure if this is a preact or an antd issue.

[rschristian]

Sorry for the delay here.

Are you testing in dev mode, or built production bundles? I was not able to reproduce with the latter.

Unfortunately some memory leaking is expected with dev, as prefresh & debugging utilities can't let go of references so easily. For most folks this is a reasonable trade off, and if you're rerendering 700 buttons every 3 seconds in order to make it visible, I'd hope it's reasonable in this situation too.

[ferretwithaberet]

It seems you're right, I've only tested using dev mode. I tried production mode now and the leak is not present anymore.

[JoviDeCroock]

@ferretwithaberet feel free to post any pointers to https://github.com/preactjs/prefresh we'd be happy to resolve some of these leaks. For the time being if it becomes problematic you can turn off prefresh in your development env and that should take care of it.

Any PR's to prefresh are enormously appreciated, I have had very little time to spend on the project.