Steps to reproduce:

Create a modal with a focus trap or use the one from https://www.w3.org/TR/wai-aria-practices-1.1/examples/dialog-modal/dialog.html

Open up the dialog that traps the focus.

Open up the developer tools and inspect the tabbing order.

Actual results:

The tabbing order is displayed as if there is no focus trap. Meaning it's misleading information. It displays various non reachable elements as focusable and shows wrong indexes for the ones that are.

https://stackoverflow.com/questions/70528783/should-a-focus-trap-prevent-a-user-from-reaching-the-context-ui-like-e-g-the-br

Expected results:

The tabbing order is correctly displayed. Only the focusable elements within the dialog should be marked and counted.

Hello, thank you for the bug report!
Managed to reproduce your issue on:

• Firefox 119.05;
• Nightly 120.0a1;
• Firefox 118.0.1;

Tested on:

• macOS 12;
• Windows 10;
• Ubuntu 22;

Moving the Product to ‘DevTools’ and Component to ‘Accessibility Tools’. Please change if there’s a better fit, thank you.
Setting as NEW so the developing team can take a look.

Wow, this is an interesting behavior - great catch, :kai, thank you for reporting it!

Marking its severity as S3, because while the bug is not blocking users from the tool, it does provide a misleading information, especially when the dialog is included at the end of the DOM and appears as the last group of focusable elements in the A11y Tools-presented focus order.