Don't Be Fooled By The Coverage Report
From NeoWiki
- Are your test coverage measurements leading you astray?
Andrew Glover, President, Stelligent Incorporated
31 Jan 2006
- Test coverage tools bring valuable depth to unit testing, but they're often misused. This month, Andrew Glover brings his considerable expertise in this area to his new series, In pursuit of code quality. This first installment takes a closer look at what the numbers on the coverage report really mean, as well as what they don't. He then suggests three ways you can use your coverage to ensure code quality early and often.
Do you remember what it was like before most developers jumped on the code quality bandwagon? In those days, a skillfully placed main() method was considered both agile and adequate for testing. Yikes! We've come a long way since then. I, for one, am immensely grateful that automated testing is now an essential facet of quality-centric code development. And that's not all I'm grateful for. Java™ developers have a plethora of tools for gauging code quality through code metrics, static analysis, and more. Heck, we've even managed to categorize refactoring into a handy set of patterns!
All these new tools make it easier than ever to ensure code quality, but you do have to know how to use them. In this series of articles, I'll focus on the sometimes arcane details of ensuring code quality. In addition to familiarizing you with the variety of tools and techniques available for code quality assurance, I'll show you how to:
- Define and effectively measure the aspects of your code that most impact quality.
- Set quality assurance goals and plan your development efforts accordingly.
- Decide which code quality tools and techniques actually meet your needs.
- Implement best practices (and weed out poor ones) so that ensuring code quality early and often becomes a painless and effective aspect of your development practice.
I'll start this month with a look at one of the most popular and easy additions to a Java developer's quality assurance toolkit: test coverage measurement.