So if you’ve heard about Ruby, you’ve probably heard about method_missing (short summary: if an object receives a message it doesn’t understand it calls method_missing which you can overwrite. This allows Rails ActiveRecord to handle User.find_by_email_and_name_and_phone_number on the fly -- it parses the message and gives you the method you want dynamically). But when too many things try to use it at once you get some interesting problems. At some point RSpec enabled calling object_instance.should_include('thing') by using method_missing on Object to catch any message that started with should_. So, in the previous example, RSpec would look for a method called include? on the object_instance, pass 'thing' into that, and tell you about it if it failed. Which is pretty cool because instead of saying: assert_equal ['a', 'b', 'c'], object_instance.some_method you could say: object_instance.should_eql ['a', 'b', 'c'] w...