getElmScrollRecursive fails on SVG in some browsers

When recursing through the DOM to calculate the scroll position here: https://github.com/dequelabs/axe-core/blob/83daaa53023c8ad5ea927244617cf7807bf1fd37/lib/core/utils/scroll-state.js#L32-L40

If the code encounters an SVG it essentially runs, document.querySelector('svg').children. This doesn’t always return an HTMLCollection object which in turn causes Array.from to error.

JS fiddle demonstrating issue: https://jsfiddle.net/uvftjtre/2/ (version 3.0.0.alpha.4)

Running the above example in EDGE:

Array.from: argument is not an Object

Running in IE11 will return:

TypeError: Array.from requires an array-like object - not null or undefined

This error surfaced when running automated tests through Phantom JS 1.9.7

More context: https://stackoverflow.com/questions/7935689/what-is-the-difference-between-children-and-childnodes-in-javascript#7935719

[emilyrohrbough]

Do you expect the changes be to add fallback for childNodes like:

- return Array.from(root.children).reduce((scrolls, elm) => { 
+ return Array.from(root.children || root.childNodes || []).reduce((scrolls, elm) => { 

or are the scroll position of SVG children necessary to worry about?

[benbcai]

@WilcoFiers This issue causes our accessibility tests to fail on any page that contains an SVG element. Looks like this is scheduled to be fixed in axe-core 3.4. Do you have a timeframe when 3.4 is scheduled to be released?