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Type error: Cannot read property data of null

See original GitHub issue

Getting an error thrown by both Preact & React with the following message:

Uncaught TypeError: Cannot read property 'data' of null

I have tried to debug this issue, but it seems like there’s something going on deeper in Goober. I believe the issue is caused here, in this minified file:

When I reload the page, everything seems to be fine again, so it doesn’t happen every render 🤔 Any help is appreciated 😃

Cheers!

Issue Analytics

State:
Created 3 years ago
Reactions:1
Comments:9 (9 by maintainers)

Top GitHub Comments

2reactions

cristianbotecommented, May 7, 2020

Heyo! @mjanssen thanks for opening this issue.

TL;DR; goober expects a textNode to exist inside the style tag. Meaning in here https://github.com/mjanssen/nextjs-goober/blob/master/pages/_document.js#L21 you should do html: ' ' + this.props.css.

The textNode exists so goober can avoid the reflow/repaint from updating the contents, via a textNode.data property update. This one is a really odd one TBH, and tried before to move to insertRule which could lead to better perf, but in goober’s case the metrics were the same.

I think this should be documented somewhere, or at least part of the next-with-goober example somewhere.

2reactions

lucat1commented, May 7, 2020

Ahh yes you got it right. The style element exists but its firstChild is null. That’s why it errors.

The easiest fix on your side could be to just put a space before extractCss