[quantumhobbit]

It is less a question of whether the percentage is correct than whether the tests are useful. I've seen plenty of useless tests (testing getters and setters in Java) that assert nothing related to the codes functionality but exist solely to boost coverage. Which is why asserting a strict coverage percentage is dangerous.

Better to just do real TDD in the first place.

[jghn]

This. Slavish fetishization of a specific code coverage target is indicative of an underlying problem, IMO and that problem is far greater than one having relatively low code coverage.

It is far better IMO to go in with an understanding of where your potential hot spots are than simply adding a test to everything. Sure, in an ideal world we'd have 100% coverage of everything but this field is about tradeoffs and sometimes writing tests simply isn't worth the time it takes to have written them in the long run.