Question around focusable elements

[canaandavis]

I recently ran into an issue where, inside of a modal, I was including an iframe. I was wanting to exclude the iframe from the tab index, so I added tabindex="-1" to the element. Though, when the modal was shown the iframe was still being focused.

I started to try and understand how elements are being selected for focus and came across the getFocusableNodes function which uses FOCUSABLE_ELEMENTS.

The FOCUSABLE_ELEMENTS constant does seem to insinuate that it is intending to exclude elements with a negative tab index however, I was still seeing my element being focused.

I started fiddling with this a little more and what I was seeing is that, in order for this query selector to work, we would actually need to append :not([tabindex^="-"]) to each query selector inside of FOCUSABLE_ELEMENTS.

I’ve created a JS Bin to illustrate the issue.

It’s quite possible that there is something I’m misunderstanding here. So if that is the case I apologize. Though, if this is an actual issue that needs to be addressed, I’d be more than happy to create a PR and walk through the process with that.

Thank you for the awesome library, and please let me know if there is any additional information you need from me!