Version 0.8.0 of the rcov code coverage tool for Ruby introduces new
output modes and superior emacs integration. It also fixes a nasty bug in the rcovrt extension. If you have been getting
segfaults or bus errors when using rcov with RSpec, give 0.8.0 a try.
If you are new to rcov, take a look at
this sample report.
In addition to indicating which code has been covered by your tests, rcov
allows you to navigate through your code easily. rcov records where each
method was called from and can generate fully cross-referenced reports,
letting you inspect the control flow. This is most useful when you're trying
to understand the overall organization of third-party code or you're refactoring.