Suspense component.__hooks might be null

[johakr]

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

Describe the bug
There seems to be a regression with lazy Suspense and hooks, triggering this error message Cannot set property __h of null, resulting in the component infinitely rendering the fallback markup.

Everything seems to work fine until preact 10.5.4. First broken version seems to be preact 10.5.5.

Changing this condition

preact/hooks/src/index.js

Line 295 in e523a82

if (component._parentDom) {

to if (component._parentDom && component.__hooks) seems to fix the issue. But I don't have enough understanding of the preact core to tell if that is the right approach & place to fix it.

To Reproduce

#2488

Expected behavior
Suspense switches out of fallback.

[davidrhoderick]

As of 10.5.14, I get a t.__H is null error. When I downgrade to 10.5.4 it goes away.

[developit]

@davidrhoderick does the error happen when you modify hook state after a component is suspended? Or is something else triggering rendering?

A few of the comments in the linked issue mention this only happens with Suspense from preact/compat, and not with ErrorBoundary/lazy from preact-iso, which makes me think it's the hook state preservation code in compat that is causing the issue.

[davidrhoderick]

It's a rather complex application so I am not able to quickly test that but I can definitely tell you that hook state is being modified in suspended components. Also suspended components load other suspended components.

[ruben-tkww]

Same issue here Cannot set property __h of null and also working fine with 10.5.4

[JoviDeCroock]

This has been fixed with 10.18.1 1658d43