Using Bazel to generate coverage report

Question

I am using genhtml command to generate html coverage report from Bazel generated coverage.dat file:

genhtml bazel-testlogs/path/to/TestTarget/coverage.dat --         


        

Answer 1

I was not able to find a way to get coverage.dat files as an output of a bazel rule. However, I was able to wrap all the locations of all the .dat files as srcs to a filegroup in WORKSPACE directory:

filegroup(
    name = "coverage_files",
    srcs = glob(["bazel-out/**/coverage.dat"]),
)

and then use that filegroup in a custom .bzl rule that wraps the genthml command to generate html coverage report. So now I only have to call

bazel coverage //path/... --instrumentation_filter=/path[/:]

command to generate the coverage.dat files, generate html report and zip it up. Thus, bazel handles everything.