I've spent this week describing the functionality and purpose of the MCOVERAGE system option introduced in SAS V9.3. Coverage testing is an important consideration for your testing strategy - it's important to know how much of your code has been tested.
As its name suggests, MCOVERAGE only logs macro coverage. It's a great shame that there isn't an equivalent for DATA steps. Perhaps it will be added in due course, to DATA steps or DS2, or both.
With some planning, and judicious use of some post-processing capability to make sense of the log(s), MCOVERAGE can be an important tool in your testing arsenal.
I note that HMS Analytical Software GmbH's testing tool (SASunit) includes coverage testing through the use of MCOVERAGE. I've not used SASunit myself, and I can't speak for how complete, reliable and supported it may be, but if you're interested in learning more I suggest you read the SASUnit: General overview and recent developments paper from the 2013 PhUSE conference and take a look at SASunit's SourceForge pages.
What is your experience with using coverage testing and/or MCOVERAGE? Post a comment, I'd love to hear from you.
NOTE: Macros Newness in 9.4 and 9.3 (MCOVERAGE), 6-Jan-2014
NOTE: Macro Coverage in Testing (MCOVERAGE), 7-Jan-2014
NOTE: Making Sense of MCOVERAGE for Coverage Testing of Your Macros, 8-Jan-2014
NOTE: Expanding Our Use of MCOVERAGE for Coverage Analysis of our Macro Testing, 9-Jan-2014
NOTE: Wrap-Up on Test Coverage and MCOVERAGE, 10-Jan-2014 (this article!)