Menu
I have a test double that I'd like to be able to receive any message.
I know I can expect the double to receive a certain message and return a value like so:
foo = double()
allow(foo).to receive(:bar) { "Foobar" }
I can also allow foo to receive any message using #as_null_object like:
foo = double()
foo.as_null_object
Is there any other syntax for this? Seems I should be able to do something like:
allow(foo).to receive(:anything)
532
A Double is an object which can “stand in” for another object. You're probably wondering what that means exactly and why you'd need one. This is a simple class, it has one method list_student_names, which returns a comma delimited string of student names.
Use the allow method with the receive matcher on a test double or a real. object to tell the object to return a value (or values) in response to a given. message. Nothing happens if the message is never received.
You can't mock an instance variable. You can only mock methods. One option is to define a method inside OneClass that wraps the another_member , and mock that method. However, you don't have to, there is a better way to write and test your code.
A partial test double is an extension of a real object in a system that is instrumented with. test-double like behaviour in the context of a test. This technique is very common in Ruby. because we often see class objects acting as global namespaces for methods.
allow and expect methods can be used to stub methods/set expectations on particular method. Augmenting object with null object pattern is quite different, and thus uses different method call.
Please note that you should usually not use null object in area that is tested by particular test -- it is meant to imitate some part of the system that is side effect of tested code, which cannot be stubbed easily.
94
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
