Google Stubs

The Google Testing Blog points us to stubs; one of the things I never get right with unit tests.

To summarize:

• Test Double is a generic term for any test object that replaces a production object.
• Dummy objects are passed around but not actually used. They are usually fillers for parameter lists.
• Fakes have working implementations, but take some shortcut (e.g., InMemoryDatabase).
• Stubs provide canned answers to calls made during a test.
• Mocks have expectations which form a specification of the calls they do and do not receive.

... which I rarely make use of.

Instead of actually connecting to a database and reading information, a stub just returns the results you'd expect, or simulates a failure; and so forth.