Unnecessary/unused check "has-listitem"

[stephenmathieson]

Currently, axe-core (version 3.1.1) contains a check called has-listitem, but it is not used by any rules. Because it's not used by any rules, it never receives a .data property in the axe._audit object, which prevents runtime localization from working.

When we attempt to apply locale at runtime, this error is raised:

axe-core/lib/core/base/audit.js

Line 188 in c8b1d62

throw new Error(`Locale provided for unknown check: "${id}"`);

This is due to the existing locale for the check:

axe-core/locales/de.json

Lines 432 to 435 in c8b1d62

	"has-listitem": {
	"pass": "",
	"fail": "Das Listen-Element besitzt kein <li>-Element."
	},

Link to live demo: https://codepen.io/anon/pen/xaYrYE

---

My suggestion is we remove the unused check, since it's currently only adding confusion and size to the built axe.js file.

Alternately, we can remove the runtime exception, but that will prevent users from seeing problems in their locale files.

[jeeyyy]

+1 for removing the unused check.

[WilcoFiers]

Removing it would be a breaking change though.

[stephenmathieson]

@WilcoFiers I don't follow. Since no rules use it, I don't understand why it'd be a breaking change.

Can you please elaborate?

[jeeyyy]

@stephenmathieson - I might be wrong, but any deprecation with in axe-core is considered a breaking change.

There is an issue around how to improve deprecation - #1062, perhaps worth creating a proposal for that, and make sure it tackles this issue too.

[WilcoFiers]

@stephenmathieson It's a breaking change because custom rules might be using it. If we pull it, anyone with a custom ruleset using this check could see errors.

[stephenmathieson]

OK, that makes sense.

How should we move forward here? Should we remove the runtime exception? Is there a way to add a .data property to the check?

[stephenmathieson]

@WilcoFiers any thoughts here? This is currently causing problems and makes the runtime localization feature not work.

[marcysutton]

That check hasn't been referenced in a rule for over 3 years. Does removing it still count as a breaking change in that case? My vote is to remove it ASAP. e62ad82#diff-6bef49e0d993ae912a97668e575d40da