More descriptive errors

[alexkreidler]

Currently, a failed input validation will result in RequestValidationError: Schema validation error, which doesn't provide any details on which paramater/body field are missing, the wrong type, or otherwise caused the error. This might need passing an option to the underlying validation library.

[VolodymyrMachekhin]

+1 to it, @alexkreidler have you found a workaround to it?

[supertong]

Hey, I believe that's due to how koa handles the error. We have expose all the details in the error object here, however, since we are using ctx.throw to throw the error, koajs by default would only return the message of the error back to the client. In order to return all the details back to the client, the best solution for now is to use a custom error handler.