Axe-core: axe extension in chrome causing disruptive behavior for syntax highlighting with eleventy-plugin-syntaxhighlight

[tannerdolby]

Hello dequelabs team!

This issue is in reference to Major issue with syntax-highlight plugin for multi-line code blocks within eleventy-plugin-syntaxhighlight.

I wanted to inform you that when I have the chrome extension axe - Web Accessibility Testing enabled, it causes disruptive behavior to eleventy-plugin-syntaxhighlight for highlighting fenced code blocks with Prism.

It causes multi-line fenced code blocks to become single line and disregards the white-space: pre style in the Prism stylesheet. It looks like its causing white-space: pre to be white-space: nowrap where everything is in a single line. (Not sure if this is the exact cause but thats what it looks like)

Expectation: Expect the accessibility testing extension not to cause disruptive behavior to the syntax highlighting that is handled by Prism.js within eleventy-plugin-syntaxhighlight.

Actual: Having the axe - Web Accessibility Testing extension enabled with access to "all sites" causes multi-line code blocks that are highlighted with eleventy-plugin-syntaxhighlight to have their styling messed up causing everything to be in a single line ignoring the CSS that should create line breaks.

Screenshot of a multi-line code block that is forced to be single line when the accessibility extension is enabled with "site access: all sites"

Screenshot of axe extension site access details

Motivation: I want the behavior to be changed so I can continue to use the axe - Web Accessibility Testing extension alongside eleventy-plugin-syntaxhighlight without having to configure any non-default behavior.

Currently as a workaround, @5t3ph pointed out that having the extension enabled with site access: on click is one way to avoid the issue I've stated above.

axe-core version: 4.6.2

Browser and Assistive Technology versions

For Tooling issues:
- Node version: v11.0.0
- Platform:  MacOS

[straker]

Thanks for the issue. @scurker This seems to have popped back up again from https://github.com/dequelabs/axe-core/issues/1868

[tannerdolby]

Your welcome. I only encountered this issue while using Chrome, not sure if its reproduced in other browsers.

[mgostisha]

Your welcome. I only encountered this issue while using Chrome, not sure if its reproduced in other browsers.

I reproduced this in Microsoft Edge v87.0.664.55. Not really surprising, but another data point.

[garretthyder]

I'm also seeing similar on Chrome when browsing datatables.net, I'd originally logged a ticket there before finding the cause was axe.
https://datatables.net/forums/discussion/comment/184320

[dzwarg]

This is also disrupting syntax highlighting by highlightjs. See the "HTML" pane at the bottom of page content here:

https://patterns.boston.gov/components/detail/brc.html

[darekkay]

Same issue as in #2686

[scurker]

Closing this issue in favor of #2686. Please continue discussion there.