In this entry, I present a summary of the features of mock frameworks. In particular, I looked at two different mock frameworks: easyMock (MIT Licence), Mockito (Apache Licence) and JMock (probably equivalent to BSD, MIT or Apache but I am not completely sure). The Mockito framework seems to be trying to extend even more the features of the easy mock.
Usual Use Cases of Mock Objects
I adapted the following list from a wikipedia entry. It shows the cases where it a good practice to use mocks.
- results of method do not follow a very deterministic pattern
- The mock can simulate a complex object or an object difficult to obtain, e.g a given state in a GUI
- A state of a system which is expensive to create, resource, processing, power...
- The object has not yet been provided, perhaps by an other team
Here are some useful posts on mocks:
- Mocks, Fakes, Stubs and Dummies , Gerard Meszaros explaining the different type of test doubles.
- Let's Spy
- Mocks and Stubs aren't Spies
I notice this post is not at all too clean. It needs to explain the purpose of spying and the difference there is with mock objects which are only dummy object or fake object.
