Made coverage reporting fit for GitHub Actions

Details:

* Increased minimum version of 'coverage' to 5.0 in order to be able
  to specify 'relative_files=True" in the 'coveragerc' config file,
  which causes the file paths in the .coverage data file to be relative.
  This was originally needed to use a github app for reporting to
  coveralls (which is no longer used), but it seems like a good idea
  in general.

* Because coverage 5.0 does not support Python 3.4, disabled generating
  and reporting coverage data in the makefile, test.yml workflow file,
  and when installing dependent packages in the requirements and constraint
  files.

* Migrated from 'python-coveralls' to 'coveralls' because the former
  does not support GitHub Actions in parallel mode (it picks the run
  ID that is used by coveralls.io to combine the reports automatically
  from Travis and does neither allow specifying it from the outside,
  nor does it support other CI systems than Travis). Also,
  python-coveralls does not seem to be maintained anymore and its last
  officially supported Python version is 3.6.

* Since 'coveralls' 2.x only supports Python 3.5 and upwards, and
  'coveralls' 1.x is incompatible with the run ID, a fork of
  'coveralls' 2.x with Python 2.7 backport support is used on
  Python 2.7.

Signed-off-by: Andreas Maier <andreas.r.maier@gmx.de>

.coveragerc

@@ -9,6 +9,10 @@
 # TODO: Once statement coverage gets better, enable branch coverage.
 branch = False
 
+# If True, stores relative file paths in data file (needed for Github Actions).
+# Using this parameter requires coverage>=5.0
+relative_files = True
+
 # The following files are omitted in the coverage.
 # omit =
 

.github/workflows/test.yml

@@ -122,7 +122,7 @@ jobs:
         COVERALLS_PARALLEL: true
         COVERALLS_FLAG_NAME: "${{ matrix.os }},${{ matrix.python-version }},${{ matrix.package_level }}"
       run: |
-        if ! [[ ${{ matrix.python-version }} =~ (2.7|3.4) ]]; then coveralls; fi
+        if ! [[ ${{ matrix.python-version }} =~ (3.4) ]]; then coveralls; fi
     - name: Run installtest
       env:
         PACKAGE_LEVEL: ${{ matrix.package_level }}
@@ -134,23 +134,14 @@ jobs:
       run: |
         make testdict
 
-  finish:
+  test_finish:
     needs: test
     runs-on: ubuntu-latest
+    container: python:3-slim
     steps:
-    - name: Checkout repo
-      uses: actions/checkout@v2
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v2
-      with:
-        python-version: 3.9
-    - name: Development setup
-      env:
-        PACKAGE_LEVEL: ${{ matrix.package_level }}
+    - name: Install coveralls
       run: |
-        make develop
-        echo "Installed Python packages:"
-        pip list
+        pip3 install --upgrade coveralls
     - name: Send coverage finish to coveralls.io
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Makefile

@@ -228,6 +228,12 @@ else
   pytest_warning_opts := -W default -W ignore::PendingDeprecationWarning
 endif
 
+ifeq ($(python_mn_version),py34)
+  pytest_cov_opts :=
+else
+  pytest_cov_opts := --cov $(package_name) $(coverage_report) --cov-config .coveragerc
+endif
+
 # Files to be put into distribution archive.
 # This is also used for 'include' statements in MANIFEST.in.
 # Wildcards can be used directly (i.e. without wildcard function).
@@ -568,7 +574,7 @@ endif
 .PHONY: test
 test: $(test_deps)
 	@echo "Makefile: Running unit tests"
-	py.test --color=yes --cov $(package_name) $(coverage_report) --cov-config .coveragerc $(pytest_warning_opts) $(pytest_opts) $(test_dir)/unittest -s
+	py.test --color=yes $(pytest_cov_opts) $(pytest_warning_opts) $(pytest_opts) $(test_dir)/unittest -s
 	@echo "Makefile: Done running unit tests"
 
 .PHONY: testdict

dev-requirements.txt

@@ -12,11 +12,13 @@
 # Direct dependencies:
 
 # Coverage reporting (no imports, invoked via coveralls script):
+# We exclude Python 3.4 from coverage testing and reporting.
 # coverage 5.0 has removed support for py34
-coverage>=4.5.2,<5.0
-# python-coveralls 2.9.2 no longer has requirement coverage==4.0.3.
-python-coveralls>=2.9.2
-pytest-cov>=2.7.0
+coverage>=5.0; python_version == '2.7' or python_version >= '3.5'
+pytest-cov>=2.7.0; python_version == '2.7' or python_version >= '3.5'
+# coveralls 2.0 has removed support for Python 2.7 and 3.4
+git+https://github.com/andy-maier/coveralls-python.git@andy/add-py27#egg=coveralls; python_version == '2.7'
+coveralls>=2.1.2; python_version >= '3.5'
 
 # Safety CI by pyup.io
 # safety 1.9.0 removed support for Python 2.7 and 3.4 (and now also enforces that)

minimum-constraints.txt

@@ -137,9 +137,11 @@ pathlib2==2.3.3; python_version < '3.4' and sys_platform != 'win32'
 # Direct dependencies for development (must be consistent with dev-requirements.txt)
 
 # Coverage reporting (no imports, invoked via coveralls script):
-coverage==4.5.2
-python-coveralls==2.9.2
-pytest-cov==2.7.0
+# We exclude Python 3.4 from coverage testing and reporting.
+coverage==5.0; python_version == '2.7' or python_version >= '3.5'
+pytest-cov==2.7.0; python_version == '2.7' or python_version >= '3.5'
+git+https://github.com/andy-maier/coveralls-python.git@andy/add-py27#egg=coveralls; python_version == '2.7'
+coveralls==2.1.2; python_version >= '3.5'
 
 # Safety CI by pyup.io
 safety==1.8.7; python_version <= '3.4'