TypeError: Cannot read properties of null (reading '__H') after Preact update

[maltium]

We have a project that uses Preact that was mostly written when 10.0.0 was released. After updating to the latest Preact version, I'm getting a runtime error when mounting certain components.

After some digging I realized that this is happening upon mounting components that use hooks. Moreover, I performed a bisect on Preact version dependencies and found out that it starts to break from Preact 10.5.6 upwards (all other previous versions are fine).

To Reproduce

Unfortunately it's hard to isolate into a smaller project since the Preact part is only a small part of the whole project.

For now I've converted the affected components into class components and got things working again on the latest Preact.

[JoviDeCroock]

Are you calling render from a different component by any chance 😅 tried to analyze your stacktrace but not getting that much wiser from it, it's also the only hooks-related change as of that release. The only other option is your bundler somehow duplicating code so the options calls aren't equal anymore.

We'll need a reproduction however if it's the former.

[maltium]

@JoviDeCroock it does seem to be the case of Preact being bundled twice, once for each library, but for some reason earlier versions didn't crash. So I'm closing this, thanks.

[jakeonfire]

also having this issue. looks like it’s trying to read at this line in the un-minified source: https://github.com/preactjs/preact/blob/10.10.3/hooks/src/index.js#L135
for whatever reason currentComponent isn’t set, which i think is supposed to happen in _render.

@JoviDeCroock what did you mean by:

The only other option is your bundler somehow duplicating code so the options calls aren't equal anymore.

what options calls?

[JoviDeCroock]

Your bundler might be duplicating the preact bundle which would lead to currentComponent not being set as it would use the options from the preact that isn't used to render your DOM

[tombohub]

And what should we do to stop this double bundle?

[rschristian]

@tombohub That depends entirely upon your tooling and environment.

[super-kamil]

in my case, i had to switch from class component to functional component to get rid of this error

[rschristian]

You were probably misusing classes in some way, but would need a reproduction to offer any more guidance than that.