[Bug] Websites using prototype library crash the browser extension

[ldevernay]

🐛 Bug report

Description

Audited website is : https://www.observatoire-dpe.fr/index.php/
Firefox plugin crashes totally.
Online webhint crashes too, but only on accessibility.

Environment

• webhint version: 1.1.1
• Browser version: Mozilla/5.0 (X11; Linux x86_64; rv:69.0) Gecko/20100101 Firefox/69.0
• URL for which webhint failed: https://www.observatoire-dpe.fr/index.php/

webhint configuration

Categories:

• Accessibility
• Compatibility
• Performance
• Pitfalls
• PWA
• Security

Your target browsers:

• Recommended settings
• Custom:

Ignored resources:

• • None
• • Different origin
• • Custom:

Debug output

hint #1: Error in webhint analyzing this hint
https://webhint.io/scanner/6fa660a0-2ce2-4127-aba4-674aa7945d69#hint-axe/aria-1

[antross]

Thanks for the report @ldevernay!

Digging into this a bit I see the browser extension seems to fail when trying to snapshot the DOM:

"TypeError: Cannot read property 'attribs' of undefined
    at snapshot (<anonymous>:131:32)
    at https://www.observatoire-dpe.fr/js/prototype-1.6.0.2.js:635:20
    at https://www.observatoire-dpe.fr/js/prototype-1.6.0.2.js:595:9
    at Array.forEach (<anonymous>)
    at Array.each (https://www.observatoire-dpe.fr/js/prototype-1.6.0.2.js:594:12)
    at Array.collect (https://www.observatoire-dpe.fr/js/prototype-1.6.0.2.js:634:10)
    at snapshot (<anonymous>:129:45)
    at https://www.observatoire-dpe.fr/js/prototype-1.6.0.2.js:635:20
    at https://www.observatoire-dpe.fr/js/prototype-1.6.0.2.js:595:9
    at Array.forEach (<anonymous>)"

Given the library in the callstack I'm suspecting both webhint's browser extension DOM snapshot utility and axe-core (which powers webhint's accessibility checks) are being affected by overrides to native APIs in the page.

[molant]

Seems that #3262 might be related to this as well.