Chapter 1, Getting to Grips with Test-Driven Development

1. The testing pyramid specifies how automated test suites should be structured. At the bottom of the pyramid are unit tests, which test a single isolated component. Next up in the middle of the pyramid are integration tests, which test that multiple components are able to work together as specified. Finally, at the top of the test pyramid are end-to-end tests that test the behavior of the entire application.
2. Functional tests cover the correctness of a system, while non-functional tests cover the usability and performance of a system. Both types of tests are required to ensure that the system satisfies the customers’ needs.
3. The red, green, and refactor TDD approach refers to the three phases of the process. The red phase involves writing a new failing test for the functionality we intend to implement. The green phase involves writing enough implementation code to make all tests pass. Finally, the refactor phase...