The Term “Unit Test”

The phrase “unit test” means so many different things to different people, that we need some new terminology to describe the tests involved in test driven development (TDD).

I gave a presentation on unit testing, and there was some pushback on the “unit tests must run fast” rule. Michael Feathers says, “Unit tests run fast.  If they don’t run fast, they aren’t unit tests.” (p. 14) Someone said that they wrote a unit test that tested all possible input (all numbers in range), and that took a couple if seconds to run, but they wanted to fully test it. It tests the unit, so isn’t it a unit test?