Why does SeaLights provide method-level coverage and not line-level coverage?

Unlike unit test coverage where you are testing only the specific methods and therefore need that higher granularity, SeaLights captures coverage from the entire business flow through all the methods and other services. This means that even though there will be situations where methods are considered covered when not all their branches were covered, all the methods those uncovered lines call will not be covered and will be reflected through them in the modified coverage (and they will appear in the testing gap analysis that SeaLights provides).

We have found from our experience that the gain in accuracy is small whereas the increase in difficulty of investigation is major and therefore recommend to concentrate on the method level. This is because SeaLights concentrates on the modified coverage which is the highest risk area. Looking at line coverage will increase the number of untested modified code to a number that will be hard to work on and that discourages teams from closing their testing gaps and raising their quality. Our customers that only used method coverage successfully increased their quality and reduced production issues by over 90% without the need to work with line coverage.