Summary
In this chapter, we went through the whys and hows of tests to describe how a good testing strategy is required to produce high-quality software and prevent problems once the code is in use by customers.
We started by describing the general principles behind testing, how to make tests that provide more value than their cost, and the different levels of testing to ensure this. We saw the three main levels of tests, which we called unit tests (parts of a single component), system tests (the whole system), and integration tests in the middle (a whole component or several components, but not all).
We continued by describing different strategies to ensure that our tests are great ones, and how to structure them using the Arrange-Act-Assert pattern, for ease of writing and understanding them after they are written.
Later, we described in detail the principles behind Test-Driven Development, a technique that puts tests at the center of development, which mandates writing...
