A truly effective unit test validates not only the correct behavior of code, but also enforces effective design. This means unit tests don't begin and end with tools like JUnit – additionally, they require an understanding of some of the key principles of good object oriented design such that a program can be written with test-ability in mind. A little investment up front to lay a good foundation can pay dividends down the road as a system evolves into something more complex; putting an even greater importance on the suite of tests that ensure its correct functioning from one release to the next.
‎Tristan Baker is an Architect with the TurboTax group at Intuit in San Diego with more than 10 years of experience designing service platforms and the teams that build them. His current work focuses on building real time data platforms that will enable the next generation of adaptive and personalized TurboTax products.