Remove orphaned children accessible tests, or clarify ARIA spec

[nmlapre]

The web platform tests have a number of cases verifying the roles of "orphaned" accessible nodes with expected parent/child role relationships. For instance, one test expects this markup:

<button role="gridcell">x</button>

to have role "button," rather than role "gridcell," since the supposed gridcell exists outside of the context of a row.

After reviewing the ARIA spec, it seems to me that this isn't the responsibility of the user agent. In the case of gridcell, for instance, the spec puts the onus on authors:

Authors MUST ensure elements with role gridcell are accessibility children of an element with the role row.

This language appears in all of the parent/child role relationship cases I reviewed. Namely: listbox/option, menu/menuitem (and variants), table/row, table/rowgroup, row/gridcell, row/rowheader, row/columnheader, list/listitem, tablist/tab, and tree/treeitem.

Similarly, section 9.2 mentions:

User agents are not responsible for logical validation, such as the following:
[...]
4. Elements that do not correctly observe required child / parent role relationships or that appear elsewhere than in their required parent.

It seems to me that the tests are verifying a remediation not required by the ARIA spec. After discussing with @jcsteh, we're not sure whether we should implement this behavior in Firefox. Should we strike the tests from the WPT repo, or are the tests valid? Do we need a clarification of the ARIA spec?

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Referenced tests:

• in grid-roles.html
• in list-roles.html
• in listbox-roles.html
• in menu-roles.html
• in tab-roles.html
• in tree-roles.html

[cookiecrook]

Thanks for filing @nmlapre! I think we could move these specific tests into a .tentative. file or series of files. In the meantime, I'll also file a new ARIA issue.

[cookiecrook]

Unassigning myself in case someone can get to this WPT PR before I do. Please assign yourself if/when you intend to work on this imminently.

Note: this will change the 2024 Accessibility Focus Area results by removing quite a few subtests, so there will be some scrutiny on the related PR.

[nmlapre]

I'm not able to assign myself to this issue (permissions with the repo, I think) but I just posted a PR with the changes: web-platform-tests/wpt#45032. I decided to lump all the tests in a single, segmented .tentative file.

[cookiecrook]

Seems like the relevant reqs may be covered sufficiently in the Core-AAM spec. web-platform-tests/wpt#45032 (review)

[cookiecrook]

FYI, we've received some additional implementation concerns about the "orphaned roles" prose. Seems like one or more implementations may be working around this in the test context primarily, which defeats the purpose of testing… I'll be opening an ARIA spec issue and possibly moving some of these tests to .tentative files.