Custom array validation using path will only show "1 error" when hovering entries instead of the error itself

[fvieira]

Describe the bug

When making a custom array validation and using path to make the errors appear on the right array entries, it only shows "1 error" on hover, while it would be way more useful to show the error itself (and which I believe used to be the behavior in the past, not sure).

To Reproduce

Add the validation below to any non-empty array:

validation: Rule =>
  Rule.custom(items =>
    items && items.length > 0
      ? items.map(item => ({
          message: 'My error message',
          path: [
            {
              _key: (item as KeyedObject)._key,
            },
          ],
        }))
      : true,
  ),

Then go to the studio and hover the error icon in the array entries.

Expected behavior

At least when there is only one error, it should show it on hover without forcing me to go to the global validations sidebar, maybe even if there were more than one, as I'm sure they would fit.

Screenshots

Which versions of Sanity are you using?

@sanity/cli (global) 3.73.0 (latest: 3.78.1)
@sanity/cli 3.73.0 (latest: 3.78.1)
@sanity/color 2.2.5 (latest: 3.0.6)
@sanity/dashboard 3.1.6 (latest: 4.1.2)
@sanity/icons 2.11.8 (latest: 3.7.0)
@sanity/orderable-document-list 1.2.3 (up to date)
@sanity/schema 3.73.0 (latest: 3.78.1)
@sanity/types 3.73.0 (latest: 3.78.1)
@sanity/ui 2.14.0 (latest: 2.15.2)
@sanity/vision 3.73.0 (latest: 3.78.1)
sanity 3.73.0 (latest: 3.78.1)

I also tested after updating to the latest, same thing happened.

What operating system are you using?

Ubuntu

Which versions of Node.js / npm are you running?

10.1.0
v20.9.0