I strongly do agree with your approach, for the record I suppose it really comes down to what kind of coverage is important In your case you seem to take the

I strongly do agree with your approach, for the record I suppose it really comes down to what kind of coverage is important In your case you seem to take the approach of having coverage on the high level surface area Mostly I see coverage referring to the actual lines of code and branches Having high coverage of lines and branches does require having tests that even dig into your private interfaces