Add superclass role to ARIA lookup table

[NickAb]

Incorrect role type is returned for the role of dialog: lookup-table.js#L492.

Expectation: axe.commons.aria.getRoleType('dialog') returns 'window'.

Actual: axe.commons.aria.getRoleType('dialog') returns 'widget'.

Reference: https://www.w3.org/TR/wai-aria-1.1/#dialog

Motivation: I want getRoleType to return role types according to aria spec. This is so that we can use returned role type in a custom rule to run keyboard reachability checks.

axe-core version: 3.5.2

Wider issue #672 was closed with suggestion to open role specific ones.

[straker]

Thanks for the issues. @WilcoFiers will have a better idea of if this is intended or not.

[WilcoFiers]

@NickAb the "type" is not intended to be an accurate representation of the element's superclass. Admittedly, it looks way too much like the superclass, so I understand the confusion. getRoleType() === 'widget' does is tell us if the thing can be focusable. You can see that for example in the focus-order-semantics rule.

To be honest, I'd like this "type" property to get deprecated and be replaced by proper superclass, and maybe have a prop that says whether or not the thing "may" or "should" be focusable.

I think the proper solve here is to add a "superclass" property to the lookup table. Would you be open to putting in a pull request for this? Fair warning, it'll likely take 3 to 5 months before we can do another release with new features in it, so if you're in a hurry with the rule, you may want to bake a solution into the rule in the mean time.

[straker]

Link to #1677

[straker]

To fix: in the ariaRoles standard, each role should have a new property called superclassRole whose value is an array of strings taken from the role definitions in WAI-ARIA 1.1 spec.

For example, the alertdialog role should be: superclassRole: ['alert', 'dialog']

[redgardner]

Could I take a stab at this issue if no one else is working on it?

[straker]

All yours. Let us know if you need anything.

[redgardner]

I've added the superclassRole property per the linked standards. Do I need to add any additional functionality around fetching this property to getRoleType ?

[straker]

Nope. Just adding the property to the standards file should be enough. We can take care of incorporating it into the getRole stuff. We still need to figure out what we want to do with it exactly.

[redgardner]

Thanks! I've created the PR: #2600

I've signed the CLA but I'm still getting a note saying that I haven't signed it yet in the PR

[straker]

Thanks! I'll take a look. Sometimes the CLA can be finicky so I'll see what's going.

[padmavemulapati]

As this is code based, marking it as devTask. Please let me know if anything needs from QA.