test: do not generate a coverage report from tox

if we would the files would be relative to the tox virtual environments
and prefixed with '.tox/py*/lib/python*/site-packages/' - which makes
them interesting to look at but useless for consumption by other tools

Author: feeph

docs/CONTRIBUTING.md

@@ -37,17 +37,33 @@ done
 pdm install
 ```
 
-### perform unit tests:
+### testing
+
+The entire test suite (unit tests & compatibility tests) can be triggered
+by running
 
 ```SHELL
-pdm run pytest
+scripts/run_tests
 ```
 
-### perform compatibility tests:
+You have successfully run all tests when the output ends with:
 
-```SHELL
-tox
 ```
+----------------------------------------------------------------------
+If you reached this far you passed. Congratulations!
+----------------------------------------------------------------------
+```
+
+If the unit tests have run successfully coverage file in LCOV format is
+generated and stored at `coverage/lcov.info`. This file can be used by
+your IDE to indicate code coverage from within your editor window.
+- We recommend the Visual Studio Code extension
+  [Code Coverage](https://marketplace.visualstudio.com/items?itemName=markis.code-coverage).
+- Special care should be taken when modifying code that is not covered by unit tests!
+
+Branches that do not pass the test harness (e.g. due to failing unit tests
+or lowering the code coverage beneath the desired threshold) should not be
+pull-requested.
 
 ### use the demo script
 

scripts/run_tests

@@ -32,11 +32,15 @@ fi
 # https://marketplace.visualstudio.com/items?itemName=markis.code-coverage
 generate_lcov() {
     mkdir -p coverage
+    # generate coverage report in lcov and HTML format
     pdm run coverage-lcov --output_file_path=coverage/lcov.info
+    pdm run coverage html
 }
+
 trap generate_lcov EXIT
+pdm run pytest --cov=feeph.i2c --cov-report=term-missing --no-header --quiet tests/
 
-pdm run pytest --cov=feeph.i2c --cov-report= tests/
+tox
 
 echo "----------------------------------------------------------------------"
 echo "If you reached this far you passed. Congratulations!"

tox.ini

@@ -28,9 +28,7 @@ requires =
 env_list =
     lint
     type
-    coverage_clean
     py{310,311,312}
-    coverage_report
 
 ; pytest & coverage
 ; https://pytest-cov.readthedocs.io/en/latest/tox.html
@@ -70,28 +68,14 @@ commands =
 
 [testenv]
 description = install pytest in a virtual environment and invoke it on the tests folder
-depends =
-    {py310,py311,312}: coverage_clean
-    coverage_report: py310,py311,312
 set_env =
   VIRTUALENV_DISCOVERY = pyenv
 deps =
     --global-option="$(python-config --includes)" -r requirements.txt
     --global-option="$(python-config --includes)" -r requirements-dev.txt
-# generate a coverage report but do not mesurements and do not fail
-# (we will combine all measurements into a single report later on)
+# do not generate a coverage report from tox
+#   if we would the files would be relative to the tox virtual environments
+#   and prefixed with '.tox/py*/lib/python*/site-packages/' - which makes
+#   them interesting to look at but useless for consumption by other tools
 commands =
-    pytest --cov=feeph.i2c --cov-append --cov-report= --cov-fail-under=0 {posargs: tests/}
-
-[testenv:coverage_clean]
-deps = coverage
-skip_install = true
-commands =
-    coverage erase
-
-[testenv:coverage_report]
-deps = coverage
-skip_install = true
-commands =
-    coverage report --show-missing
-    coverage html
+    pytest --no-cov {posargs: tests/}