Refactor session configuration and error handling: simplify session start/delete callbacks and improve exception handling in message verification

Author: eliasjpr

spec/spec_helper.cr

@@ -11,7 +11,7 @@ class UserSession
   property username : String? = "example"
 end
 
-Session.configure do |c|
+Session.configure do
   c.on_started = ->(sid : String, data : Session::Databag) { puts "Session started - Id: #{sid} Username: #{data.username}" }
   c.on_deleted = ->(sid : String, data : Session::Databag) { puts "Session Revoke - Id: #{sid} Username: #{data.username}" }
 end

src/message/verifier.cr

@@ -35,9 +35,9 @@ module Message
       if valid_message?(data.to_s, digest.to_s)
         String.new(decode(data.to_s))
       end
-    rescue argument_error : ArgumentError
-      return if argument_error.message =~ %r{invalid base64}
-      raise argument_error
+    rescue ex : ArgumentError
+      return if ex.message =~ %r{invalid base64}
+      raise ex
     end
 
     def verify(signed_message : String) : String