Use Codecov to report coverage

Author: jan-janssen

.github/workflows/pipeline.yml

@@ -194,3 +194,32 @@ jobs:
       run: |
         pip install . --no-deps --no-build-isolation
         python -m unittest discover tests
+
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Setup environment
+      shell: bash -l {0}
+      run: |
+        echo -e "channels:\n  - conda-forge\n" > .condarc
+        sed '/- python/d' binder/environment.yml > environment.yml
+        echo '- coverage' >> environment.yml
+    - name: Setup Mambaforge
+      uses: conda-incubator/setup-miniconda@v3
+      with:
+        python-version: '3.12'
+        miniforge-version: latest
+        condarc-file: .condarc
+        environment-file: environment.yml
+    - name: Test
+      shell: bash -l {0}
+      timeout-minutes: 30
+      run: |
+        pip install . --no-deps --no-build-isolation
+        coverage run -m unittest discover tests
+        coverage xml
+    - name: Upload coverage reports to Codecov
+      uses: codecov/codecov-action@v5
+      with:
+        token: ${{ secrets.CODECOV_TOKEN }}