As an editor I want to see constraints violations on Form and Sense statements in order to see mistakes in the data and fix them.
Right now statements on the Form and Sense level are not checked for constraints violations.
https://www.wikidata.org/wiki/Lexeme:L123 has two "compound of" statements at the moment. The one on the Lexeme level shows a constraint violation because of a missing mandatory qualifier. The one on the Form level doesn't.
GIVEN a statement on a Form or Sense
AND that statement violates a constraint
WHEN loading the Lexeme page
THEN the violation should be checked and indicated via the little constraint violation icon
* statements on Forms and Senses are checked for constraint violations and indicate them to the user in the same way as constraint violations on Item or Lexeme-level statements
* given a lexeme with >50 forms + senses, it should still check all of them (make multiple requests to work around the 50 entity id limit on the API)
~~* Should `action=wbcheckconstraints&id=L1` automatically check constraints on `L1`’s forms and senses, or should the gadget add the IDs of all the forms and senses to the API request?~~ See below
`wbcheckconstraints` should stay as it is. Since it can handle multiple entity ids in one request, Form and Sense ids need to be added to the API request on the client side. (Note that only up to 50 entities may be checked per request, so the client may have to split up requests for lexemes with more forms or senses.)