It perhaps makes sense for a call to /w/api.php?action=query&format=json&prop=info&titles=Test&formatversion=2&inprop=watchlistlabels to return an array of watchlist labels (IDs? IDs and names?) for the given page

Relates to T416615: Make watchlist labels usable via API calls

Derived Requirements

1. The action=query&prop=info API must support a new inprop value: watchlistlabels.
2. When inprop=watchlistlabels is specified and the page is watched by the current user:
   • The response must include an array of watchlist labels assigned to that page.
   • Each label must include:
     • Label ID
     • Label name
   • The structure must align with the existing watchlist label format used elsewhere in the API (consistent schema and field naming).
3. If the page has no labels assigned:
   • The API must return an empty array for watchlistlabels (not omit the field).
4. If the page is not watched:
   • The API must either omit the field or return an empty array (behavior must be consistent and documented).
5. The response must respect user permissions:
   • Only return labels for the authenticated user making the request.
6. The feature must work with format=json and formatversion=2.

Test Steps

Test Case 1: API returns labels for a watched page with labels

1. Watch a page in Beta.
2. Assign one or more watchlist labels to the page.
3. Call: https://en.wikipedia.beta.wmcloud.org/w/api.php?action=query&format=json&formatversion=2&inprop=watchlistlabels&prop=info&titles=Banana
4. Inspect the JSON response.
5. ✅❓❌⬜ AC1: Response includes a watchlistlabels array under the page object, contains each label entry contains both ID and name, also returned labels match those assigned in the UI .

Test Case 2: API returns empty array when page has no labels

1. Watch a page in Beta.
2. Ensure no labels are assigned.
3. Call the same API endpoint with inprop=watchlistlabels.
4. Inspect the JSON response.
5. ✅❓❌⬜ AC2: watchlistlabels is present and is an empty array.

Test Case 3: API behavior for unwatched page

1. Ensure a page is not on the watchlist in Beta.
2. Call the API with inprop=watchlistlabels.
3. Inspect the JSON response.
4. ✅❓❌⬜ AC3: watchlistlabels` is present and is an empty array.

Test Case 4: API without inprop parameter

1. Call: https://en.wikipedia.beta.wmcloud.org/w/api.php?action=query&format=json&formatversion=2&prop=info&titles=Banana
2. Inspect the JSON response.
3. ✅❓❌⬜ AC4: No watchlistlabels field is present when inprop=watchlistlabels is not specified.

Test Case 5: Permission check

1. Log out or use a user without the page on their watchlist.
2. Call the API with inprop=watchlistlabels.
3. ✅❓❌⬜ AC5: Labels are not returned for another user’s watchlist.

QA Results -Beta