Question

One of the JUnit best practices is : same package, separate directories. I am wondering what is the equivalent for Mock classes ? Do you keep them in the same package as classes they are supposed to mock, but in the test directory ? or elsewhere ?

Answer 1

Like many things in programming, “it depends.” Here are some rules of thumb I use:

1. If I have a stub that is only used by one test and is small – create an inner class
2. If I have a stub that is only used by one test and is large – put in same package/folder as test
3. If I have a stub that is used by multiple tests in the same package – put in same package/folder as test
4. If I have a stub that is used in many places in the same application – put in a test.util package
5. If I have a stub that is used across applications, put it in a jar.

I have instances of all of these in my code.