Rendering a component on the server requires DOM (document)

I have the following stack trace when I try to render one of my pages on the server:

ERROR in ReferenceError: document is not defined
    at createNode (static:3586:163)
    at idiff (static:3627:26)
    at diff (static:3602:20)
    at renderComponent (static:3771:33)
    at renderComponent (static:3762:26)
    at cl.extend.forceUpdate (static:3917:14)
    at static:55402:16
    at Object.sig.subscribe (static:55288:10)
    at cl.React.createClass.componentWillMount (static:55401:21)
    at Object.renderToString (static:4546:34)

Somehow a code path is taken which causes a crash due to non-existing document in the global scope. I tried to follow the code in renderComponent but didn’t get far.

[wereHamster]

The error can be reproduced by this code. You need a double-nested component for the bug to be triggered. This is why you couldn’t reproduce it, because you always returned a DOM element in your render functions.

const React = require('preact-compat');
const {renderToString} = require('preact-compat/server');

const Bar = () => React.createElement('div');

class Foo extends React.Component {
  componentWillMount() {
    this.forceUpdate();
  }
  render() {
    return React.createElement(Bar);
  }
}

renderToString(React.createElement(Foo))

{
  "dependencies": {
    "preact": "^8.1.0",
    "preact-compat": "^3.15.0"
  }
}

[sirgallifrey]

I wasn’t able to reproduce the error 😦 I tried the promise example, I tried setTimeout, I tried setting a ref to setState and calling it after the render, I tried calling forceUpdate on promise, on setTimeout and none of those are throwing errors, at least not on my setup. I could just apply the correction @developit suggested but as I’m in love with TDD I can’t fix what I can’t reproduce.

It’s worth mentioning that I made these tests on

• preact-render-to-string 3.6.0
• preact 7.2.0

it would be helpful to know what versions are you using, @wereHamster including preact-compat and react-redux if you are using those.