Request Validation with Akka-HTTP and Cats
Sample Problem: User Regsitration
To start with, let us suppose that we are working on some sort of user management service using Scala/Akka. However, here we are only going to focus on the registration part, in which the client is expected to send a user data, in JSON format; and the server needs to validate them, and save the user if the validations succeed, or reject the request with all the errors detected. That said, we should keep in mind that our validations may be used through out the entire codebase, not just in the user registration endpoint.
The rules for our validation are as follows: