Return Value in Error Message when Validation Fails about protovalidate HOT 1 OPEN

Hi @cnoon! Thanks for praise and feedback. 😁

You hit the nail on the head with the value not being included in the error to avoid PII or security concerns. We want users of protovalidate to choose how they present their errors for the best and have it be safe by default. This value might also be ambiguous, such as when the violation results from a custom CEL expression at the message level that compares two fields or a message field custom constraint that might operate against subfields.

That said, internally we've also encountered this issue and have talked through some potential solutions.

We definitely want to provide a way to go from a violation error and message to the value in question. This can be done in the protovalidate implementations as a function that takes a violation error & message, and returns the value. There've been similar requests to be able to resolve the constraint definition(s) as well.

With that available, we can evaluate if it makes sense to provide configuration that automatically wraps errors with this information in the validator. I can see this getting messy when people want to conditionally include the information or not depending on a PII annotation. Wrapping the validator is still always possible to apply this feature with the helper function above, though.

from protovalidate.