Not passing a mandatory parameter generates a 500 response, shouldn't it be 400 instead?

[benjamin-thomas]

Hello! I'm finding your library very interesting, thanks for writing the "mig by example" documentation, it's a pleasure to read!

Given this handler definition

-- http GET localhost:8082/api/auth X-Token:ABC-123
auth :: Header "X-Token" Text -> Get (Resp Text)
auth (Header authToken) =
  pure $
    if authToken == "ABC-123"
      then ok "Access granted"
      else bad unauthorized401 "Invalid token"

I would expect the HTTP clients to receive an HTTP 400 bad request status code, rather than a 500 internal error status code. That's because they made a badly formed request.

Appart from making the parameters optional and checking them myself (which I feel would defeat the purpose of the library), can I override this default behavior? Or if my explanation is convincing, could the default behavior be changed?