python unittest with coverage report on (sub)processes

Question

I'm using nose to run my "unittest" tests and have nose-cov to include coverage reports. These all work fine, but part of my tests require running some code as a multiprocessing.Process. The nose-cov docs state that it can do multiprocessing, but I'm not sure how to get that to work.

I'm just running tests by running nosetests and using the following .coveragerc:

[run]
branch = True
parallel = True

[report]
# Regexes for lines to exclude from consideration
exclude_lines =
    # Have to re-enable the standard pragma
    pragma: no cover

    # Don't complain about missing debug-only code:
    def __repr__
    #if self\.debug

    # Don't complain if tests don't hit defensive assertion code:
    raise AssertionError
    raise NotImplementedError

    # Don't complain if non-runnable code isn't run:
    if 0:
    if __name__ == .__main__.:
    def __main__\(\):

omit =
    mainserver/tests/*

EDIT:

I fixed the parallel switch in my ".coveragerc" file. I've also tried adding a sitecustomize.py like so in my site-packages directory:

import os
import coverage
os.environ['COVERAGE_PROCESS_START']='/sites/metrics_dev/.coveragerc'
coverage.process_startup()

I'm pretty sure it's still not working properly, though, because the "missing" report still shows lines that I know are running (they output to the console). I've also tried adding the environment variable in my test case file and also in the shell before running the test cases. I also tried explicitly calling the same things in the function that's called by multiprocessing.Process to start the new process.

Answer 1

Another thing to consider is if you see more than one coverage file while running coverage. Maybe it's only a matter of combining them afterwards.

Answer 2

First, the configuration setting you need is parallel, not parallel-mode. Second, you probably need to follow the directions in the Measuring Subprocesses section of the coverage.py docs.