Improve AppVeyor / Coveralls integration?

appveyor.yml

@@ -12,4 +12,4 @@ build: off
 test_script:
   - cmd: '"%PYTHON%\Scripts\coverage.exe" run setup.py test'
 on_success:
-  - cmd: '"%PYTHON%\Scripts\coveralls.exe" debug'
+  - cmd: '"%PYTHON%\python.exe" "scripts\appveyor-coverage.py" "%PYTHON\Scripts\coveralls.exe"'

scripts/appveyor-coverage.py

@@ -0,0 +1,84 @@
+# Python wrapper for coverage reporting from AppVeyor to Coveralls.
+#
+# Author: Peter Odding <peter.odding@paylogic.com>
+# Last Change: October 31, 2015
+# URL: https://github.com/paylogic/pip-accel
+
+"""
+An attempt to integrate coverage from AppVeyor and Travis on Coveralls.
+
+Since version 0.33 (released on October 30, 2015) pip-accel supports the
+Windows platform and runs its test suite on Windows using AppVeyor CI. Coverage
+is also collected on Windows and reported to Coveralls. As mentioned in `the
+pull request`_ where all of this was implemented the coverage collection kind
+of works but it's not exactly ideal!
+
+This Python script is an experiment (work in progress!) in getting AppVeyor
+builds to *correctly* submit coverage statistics to Coveralls so that the
+coverage of the Linux and Windows builds is merged into one overview by
+Coveralls. I'm not even sure if that is possible (it's clearly not a supported
+use case out of the box :-) but I guess this experiment will tell me one way or
+the other.
+
+.. _the pull request: https://github.com/paylogic/pip-accel/pull/61#issuecomment-152356508
+"""
+
+# Standard library modules.
+import logging
+import os
+import pprint
+import subprocess
+import sys
+
+# External dependencies.
+import coloredlogs
+
+# Initialize a logger for this script.
+logger = logging.getLogger('appveyor-coverage-hack')
+
+
+def main():
+    """Command line interface for AppVeyor Coverage hack."""
+    coloredlogs.install(level=logging.DEBUG)
+    fix_branch_name()
+    returncode = subprocess.call(sys.argv[1:])
+    sys.exit(returncode)
+
+
+def fix_branch_name():
+    """
+    Fix the name of the branch on which coverage is reported.
+
+    AppVeyor test coverage on Coveralls is showing up on the branch name
+    ``HEAD`` instead of ``master`` which (I'm guessing) makes it impossible for
+    Coveralls to merge coverage statistics into one overview.
+
+    According to the AppVeyor documentation on `environment variables`_ the
+    environment variable ``$APPVEYOR_REPO_BRANCH`` should tell us whether we're
+    operating on the ``master`` branch.
+
+    Judging by `the source code`_ of the Python integration for Coveralls the
+    ``$CI_BRANCH`` environment variable can be used to change the branch name
+    that's reported to Coveralls.
+
+    .. _environment variables: http://www.appveyor.com/docs/environment-variables
+    .. _the source code: https://github.com/coagulant/coveralls-python/blob/master/coveralls/api.py
+    """
+    logger.debug("Existing environment variables (sanitized): %s", dump_environment())
+    if os.environ.get('APPVEYOR_REPO_BRANCH') == 'master' and os.environ.get('CI_BRANCH') != 'master':
+        logger.debug("Fixing $CI_BRANCH environment variable ..")
+        os.environ['CI_BRANCH'] = os.environ['APPVEYOR_REPO_BRANCH']
+        logger.debug("Modified environment variables (sanitized): %s", dump_environment())
+    else:
+        logger.debug("Not fixing $CI_BRANCH environment variable ..")
+
+
+def dump_environment():
+    """Get pretty printed environment dictionary without Coveralls repository token."""
+    variables = dict(os.environ)
+    variables['COVERALLS_REPO_TOKEN'] = '[secure]'
+    return pprint.pformat(variables)
+
+
+if __name__ == '__main__':
+    main()