So I was asked an interesting question today at our VSTS/ALM Seminar in Phoenix: Is code coverage data collected as part of a load test?
Well, yes and no.
- No: Code coverage info is collected as part of running a unit test, not a load test.
- Yes: If you run a unit test as part of a load test, code coverage is implicitly collected because the load test is calling that unit test (over and over).
Last element to note: When viewing code coverage results for a load test run (again, collected when unit tests are included in the test mix for a load test), the data you’re viewing is aggregated from all the unit test runs. This is actually a good thing – I can run a load test that executes a unit test 100,000 times very quickly. I don’t want to look through each run, but rather the cumulative result for code coverage. This is possible because code coverage is primarily a percentage value.
This aggregate view is based on the unit test, regardless if the unit test is a "static" or data-driven test (a data-driven test can alter the code coverage results between runs, so again, and aggregate view is easiest to interpret).