Improve content type mismatch error message

Author: johannesluedke

lib/openapi_first/router/find_response.rb

@@ -17,20 +17,21 @@ def self.call(responses, status, content_type, request_method:, path:)
         end
         response = FindContent.call(contents, content_type)
         if response.nil?
-          message = "#{content_error(content_type, request_method:,
-                                                   path:)} Content-Type should be #{contents.keys.join(' or ')}."
-          return Match.new(error: Failure.new(:response_not_found, message:), response: nil)
+          message =
+            "Content-Type should be #{contents.keys.join(" or ")}, " \
+              "but was #{content_type&.empty? ? "empty" : content_type} for " \
+              "#{request_method} #{path}"
+          return(
+            Match.new(
+              error: Failure.new(:response_not_found, message:),
+              response: nil
+            )
+          )
         end
 
         Match.new(response:, error: nil)
       end
 
-      def self.content_error(content_type, request_method:, path:)
-        return 'Response Content-Type must not be empty.' if content_type.nil? || content_type.empty?
-
-        "Response Content-Type #{content_type} is not defined for #{request_method} #{path}."
-      end
-
       def self.find_status(responses, status)
         # According to OAS status has to be a string,
         # but there are a few API descriptions out there that use integers because of YAML.