False positive link-in-text-block error

[SaschaUvA]

• [1.3.2] Ace version
• [v20.11.0] Node version
• [Windows 11 - Version 10.0.22631 Build 22631] OS and version
• [post_patch.zip] input EPUB file as a .zip

Hi Ace team!

I found that I was getting an unjustified link-in-text-block error for an EPUB that I was processing.
The link in question does have an underline and should thus fulfill the requirements for an accessible link within the contexts of the error.

For this particular EPUB, I have added a picture of the Ace report details alongside the XHTML code + example.
I observed this error in another EPUB file as well (not attached due to size limits) and it also happened when the link text was just an asterisk: *.
Perhaps the issue is related to that.

I hope this paints a clear picture, if you have any further questions, don't hesitate to ask!

Best,
Sascha

[danielweck]

Hello, Deque Axe is used internally by Axe to evaluate colour contrast (which seems to be failing in your case). This is a WCAG 2.0 (A) "serious" error, but unfortunately I am noticing inconsistencies depending on what web browser engine is used to run the evaluation (and whether it is headless or not). Ace has always used Chromium, but the legacy Puppeteer underlying system has been deprecated in favour of using Electron for both Ace (CLI) and Ace App (GUI). Puppeteer is headless, Electron is not. In principle, this is a positive, because headless seems to be the one incorrectly reporting colour contrast issues. However this also means that EPUB publications that used to pass the test now fail. I am investigating this further in preparation of the upcoming Ace update.
https://dequeuniversity.com/rules/axe/4.10/link-in-text-block