add format check

.github/workflows/formatting.yml

@@ -0,0 +1,31 @@
+name: formatting
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  checks:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.9"]
+        poetry-version: ["1.2.1"]
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Set up Poetry ${{ matrix.poetry-version }}
+        uses: abatilo/actions-poetry@v2
+        with:
+          poetry-version: ${{ matrix.poetry-version }}
+      - name: Install packages
+        run: poetry install --with dev
+      - name: Check black
+        run: poetry run black --check .
+      - name: Check isort
+        run: poetry run isort --check-only .