Throwing exceptions in switch statements when no specified case can be handled

Question

Let\'s say we have a function that changes a password for a user in a system in an MVC app.:

public JsonResult ChangePassword
    (string username, string curren         


        

Answer 1

For a web application I would prefer a default that generates a result with an error message that asks the user to contact an adminstrator and logs an error rather than throws an exception that might result in something less meaningful to the user. Since I can anticipate, in this case, that the return value might be something other than what I expect I would not consider this truly exceptional behavior.

Also, your use case that results in the additional enum value shouldn't introduce an error into your particular method. My expectation would be that the use case only applies on login -- which would happen before the ChangePassword method could legally be called, presumably, since you'd want to make sure that the person was logged in before changing their password -- you should never actually see the ContactUs value as a return from the password validation. The use case would specify that if a ContactUs result is return, that authentication fails until the condition resulting in the result is cleared. If it were otherwise, I'd expect that you'd have requirements for how other parts of the system should react under that condition and you'd write tests that would force you to change the code in this method to conform to those tests and address the new return value.