Unit Testing Code Coverage: Myths, Mistakes, and Realities

You've committed to an agile process that encourages test driven development. That decision has fostered a concerted effort to actively unit test your code. But, you may be wondering about the effectiveness of those tests. Experience shows that while the collective confidence of the development team is increased, defects still manage to raise their ugly heads. Are your tests really covering the code adequately or are big chunks remaining untested? And, are those areas that report coverage really covered with robust tests? Andrew Glover explains what code coverage represents, how to effectively apply it, and how to avoid its pitfalls. Code coverage metrics can give you an unprecedented understanding of how your unit tests may or may not be protecting you from sneaky defects. In addition, Andrew describes the differences between code-based coverage and specification-based coverage, and examines open-source and commercial tools available to gather these metrics.

• The meaning of code coverage for unit testing
• Benefits and pitfalls of code coverage
• Code coverage tools available for Java and .NET