EasyMock 101
A 30 Minute Review by Matthew McCullough

❶ What Is Mocking?

Are You Mocking Me?
• A fake object
• Allows for more modular testing
• Records and verifies expectations of calls

❷ Creating A Mock

IEnumeration<Short> iEnumIntfMock =
EasyMock.createMock(EnumeratedAttribute.class);

❸ Expectations

Expecting A Lot
• Expect method is called on mock
• Expect sequence of method calls on mock
(call createStrictMock())
• Expect parameters to methods calls on
mock

Expect A Call
EasyMock.expect(iEnumIntfMock.getNumberOfRows()
);

Expect A Return
EasyMock.expect(iEnumIntfMock.getNumberOfRows()
).andReturn(5);

❹ Replaying

Replay
• Prime the pump to walk through expected
call sequence
• Provide return values in same sequence
• Listen to usage of call parameters

Replay Kickoff
EasyMock.replay(iEnumIntfMock);

❺ Using The ClassUnderTest

Testing
• Call all functions as you normally would
• Pass in mock where injectable
• Consider how mock can be passed into
internal references

Testing
int numOfRows =
iEnumIntfMock.getNumberOfRows();
Assert.assertTrue(\"Number of rows does not
match\", numOfRows > 0);

❻ Verifying

• Called after all operations with the mock
are done
• Compares the usage to the recording

Verifying
EasyMock.verify(iEnumIntfMock);

❼ Resources

Resources
• EasyMock.org
• Groovy Mocking
http://docs.codehaus.org/display/GROOVY/Groovy+Mocks