Setup

You’ve learned how to test-drive, and more importantly, you learned in the Chapter 6, ​Incremental Design​ chapter how to use TDD to shape your system’s design. Safe, continual refactoring sustains the life of your production code. In this chapter, you’ll learn how to design your tests well to extend their return on value and keep them from becoming a maintenance burden.

You’ll learn about quality tests using a few core concepts.

• The FIRST mnemonic, a great way to vet your tests

• One Assert per Test, a guideline to help constrain the size of your tests

• Test Abstraction, a core principle for readable tests