Chapter 9. Solving Test Puzzles

"We make a living by what we get, but we make a life by what we give."

—Winston Churchill

You may have worked in greenfield development projects that were written using test-driven development (TDD) and also in brownfield development or maintenance projects that were not written with TDD. You must have noticed that the test-first code written with TDD is easier to extend than the code with no unit test or unit tests written after coding.

Tip

A greenfield project starts building from scratch and doesn't consider any prior work.

A brownfield project is an extension of prior work or rebuilding a project from an existing project.

This chapter covers the importance of unit testing in greenfield and brownfield projects. The following topics are covered in depth:

• Working with legacy code

• Designing for testability

• Working with greenfield code

The Working with legacy code section covers the legacy code and explains how to unit test and refactor the legacy code. The Designing...