Add GitHub action for coverage comment (#72)

.github/workflows/coverage.yml

@@ -0,0 +1,19 @@
+name: Post coverage comment
+
+on:
+  workflow_run:
+    workflows: ["run_unit_tests"]
+    types:
+      - completed
+
+jobs:
+  test:
+    name: Run tests & display coverage
+    runs-on: ubuntu-latest
+    if: github.event.workflow_run.event == 'pull_request' && github.event.workflow_run.conclusion == 'success'
+    steps:
+      - name: Post comment
+        uses: py-cov-action/python-coverage-comment-action@v3
+        with:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_PR_RUN_ID: ${{ github.event.workflow_run.id }}

.github/workflows/run_unit_tests.yml

@@ -1,5 +1,5 @@
+name: Unit tests/Coverage
 
-name: Unit Tests and Flake
 
 on:
   push:
@@ -38,7 +38,41 @@ jobs:
           # stop the build if there are Python syntax errors or undefined names
           flake8 . --count --select=E9,E402,E501,F63,F7,F82,F401,W291,W605 --max-line-length=100 --show-source --statistics
           # exit-zero treats all errors as warnings.
-          flake8 . --count --exit-zero --max-complexity=10 --statistics
+          flake8 . --count --exit-zero --max-complexity=10 --max-line-length=100 --statistics
 
       - name: Run unit tests
         run: PYTHONPATH=test python -m pytest test/
+        env:
+          COVERAGE_FILE: ".coverage.${{ matrix.python_version }}"
+
+      - name: Store coverage file
+        uses: actions/upload-artifact@v2
+        with:
+          name: coverage
+          path: .coverage.${{ matrix.python_version }}
+
+  coverage:
+    name: Coverage
+    runs-on: ubuntu-latest
+    needs: test
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: actions/download-artifact@v2
+        id: download
+        with:
+          name: 'coverage'
+
+      - name: Coverage comment
+        id: coverage_comment
+        uses: py-cov-action/python-coverage-comment-action@v3
+        with:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          MERGE_COVERAGE_FILES: true
+
+      - name: Store Pull Request comment to be posted
+        uses: actions/upload-artifact@v2
+        if: steps.coverage_comment.outputs.COMMENT_FILE_WRITTEN == 'true'
+        with:
+          name: python-coverage-comment-action
+          path: python-coverage-comment-action.txt

pyproject.toml

@@ -39,7 +39,8 @@ target-version = ["py38", "py39", "py310"]
 include = '\.pyi?$'
 
 [tool.pytest.ini_options]
-addopts = "--cov --cov-report html --cov-report term-missing --cov-fail-under 80"
+addopts = "--cov --cov-fail-under 80"
 
 [tool.coverage.run]
 source = ["src"]
+relative_files = true