To assist in testing your code, we report the coverage of all IMP modules and applications as part of the nightly builds. Coverage is basically a report of which lines of code were executed by your tests; it is then straightforward to see which parts of the code have not been exercised by any test, so that you can write new tests to test those parts. (Of course, lines of code that are never executed have no guarantee of working correctly.)

Both the C++ and Python code coverage is reported. For C++ code, only the lines of code that were exercised are reported; for Python code, which conditional branches were taken are also shown (for example, whether both branches from an if statement are followed).

Ideally, coverage reflects the lines of code in a module or application that were exercised only by running its own tests, rather than the tests of the entire IMP package, and generally speaking you should try to test a module using its own tests. (Note also that our build machine that runs the coverage test suite does not run 'expensive' tests.)

If you have code that for some reason you wish to exclude from coverage, you can add specially formatted comments to the code. For Python code, add a "pragma: no cover" comment to the line to exclude. For C++ code, an individual line can be excluded by adding LCOV_EXCL_LINE somewhere on that line, or a block can be excluded by surrounding it with lines containing LCOV_EXCL_START and LCOV_EXCL_STOP.

If you want to run coverage on IMP yourself, see the README file in the tools/coverage directory for instructions.