fix(landmark-unique): follow spec, aside -> landmark

[gabalafou]

Update the landmark-unique rule matcher for aside elements so that they are treated as landmarks using the same criteria specified in Sections 3.4.8 and 3.4.9 of the HTML Accessibility API Mappings 1.0.

Closes: #4460

[CLAassistant]

All committers have signed the CLA.

[straker]

Thanks for being willing to take on a pr for this. Unfortunately I don't think this is the correct place for the change.

We have a file implicit-html-roles that dictates what the role of an element is when it has no role attribute. In there we assign aside the role of complimentary. Instead what we need to do is figure is two things:

1. Is the aside part of a sectioning content. We can determine this using the code from footer and header. If it's not part of a sectioning content then the function should return complementary
2. Does the aside have an accessible name. Again, we can determine this by using the local hasAccessibleName function similar to how the from role works. If it does then return complementary, otherwise return null to signify no implicit role.

Fixing that should then fix the landmark unique issue as the aside will no longer be determined to have a complementary role.

[gabalafou]

Oh that's great. Putting this aside-complementary logic in the landmark-unique matcher felt off to me, but I was patterning off of what was already there. Given what you wrote, I think the isHeaderFooterLandmark() function is redundant. In fact, I just checked and if I comment it out, then run npm run build && npm run test, all the tests pass.

Would you like me to update this pull request?

[straker]

Yep, that'd be great.

[straker]

Awesome work! Thanks for the pr.

Reviewed for security.