The fundamental principles involved here are simple and intuitive. And, amazingly, they work extremely well!
In case you haven’t picked it up by now, the extreme references have to do with Extreme Programming (XP), a style of programming that was developed in the mid-1990s. XP stresses simplicity of design, frequent small releases, aggressively creating opportunities for communications, and—in case you wondered when this section would discuss it—testing.
XP tells you to test early and test often. In XP, it’s not considered to be too early if you write the unit test even before you write the code!
This chapter isn’t about XP or development methodologies. But the integrated build/deploy/test ...