Wouldn't it be nice, if:
when coverage is merged, covered lines keep some info what tests exercised given line. in a simple case, let's say a set of xxx from .coverage_xxx is carried with each covered line.
when HTML is generated, a covered line in HTML gets a :hover or similar tag + jquery that displays what tests exercised a given line.
Why I'd like this:
Case 1. I'm trying to set up a heterogeneous test environment:
most code is covered by unit tests some code is covered by integration test vectors yes some corner cases are covered by negative tests
There's overlap between these different kinds tests and they have varying degree of certainty that just because a line was executed it produced correct result.
Comparing html files side-by-side is an option, but unified view would be cooler.
Thus I'd like to see what tests and how many exercised a given line when drilling down.
Case 2. Debugging
Let's say a large volume of tests produced awesome coverage.
Now I'll go into HTML and get all surprised that some "raise XXX" line was in fact executed. Now let's say, I expected that to be fatal and not ignored. This would allow me to quickly check which test caused that.