There have been some articles and tweets about code coverage recently, and it seems that many developers are still laboring under a few misconceptions in this area.

Code coverage can be a very useful metric. However you need to know how, and when, to use it. The link between code coverage and test quality is tenuous at best - in short, high code coverage is, in itself, no guarantee of well tested code. And increasing code coverage for the sake of code coverage will not necessarily improve either the quality of your tests or the quality of your application. It is easy (and obviously a largely futile exercise) to achieve high code coverage metrics without actually testing anything at all.