add coverage to project

We add a separate tox environment for the coverage because it cannot track
the selenium tests. In the coverage environment the tests/notebooks/*py
are just run, so the coverage through selenium actions is not covered.

Author: agoscinski

.codecov.yml

@@ -0,0 +1,10 @@
+coverage:
+  status:
+    project:
+      default:
+        target: 80%
+    patch:
+      default:
+        target: 80%
+
+comment: on

.github/workflows/tests.yml

@@ -28,3 +28,11 @@ jobs:
 
     - name: run Python tests
       run: tox -e tests
+
+    - name: run Python tests for coverage
+      run: tox -e coverage
+    - uses: codecov/codecov-action@v3
+      with:
+        files: coverage.xml
+        verbose: true
+

tox.ini

@@ -19,18 +19,34 @@ setenv =
     JUPYTER_CONFIG_DIR={envdir}/etc/jupyter
     JUPYTER_DATA_DIR={envdir}/share/jupyter
 deps =
-    notebook==7.0.2
     pytest
+    # selenium juypter notebook tests
+    notebook==7.0.2
     # fixing selenium version to have backwards-compatibility with pytest-selenium
     # see https://github.com/robotframework/SeleniumLibrary/issues/1835#issuecomment-1581426365
-    selenium==4.9.0 
+    selenium==4.9.0
     pytest-selenium
     jupytext==1.15.0
 commands =
     # converts the python files to ipython notebooks
     jupytext tests/notebooks/*.py --to ipynb
     pytest {posargs:-s -v} --driver Firefox
 
+[testenv:coverage]
+# We do coverage in a separate environment that skips the selenium tests but
+# includes the jupytext notebook files, because coverage is incompatible with
+# selenium
+deps =
+    pytest
+    pytest-cov
+    coverage[toml]
+    selenium==4.9.0
+commands =
+   pytest --cov=scwidgets --ignore=tests/test_widgets.py -o testpaths="tests tests/notebooks/*py"
+
+commands_post =
+    coverage xml
+
 [testenv:docs]
 deps =
     -r docs/requirements.txt