Run ruff check on CI

Signed-off-by: Bernd Verst <[email protected]>

.github/workflows/build.yaml

@@ -20,7 +20,35 @@ on:
   merge_group:
 
 jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Python 3.9
+      uses: actions/setup-python@v5
+      with:
+        python-version: 3.9
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install setuptools wheel tox
+    - name: Run Autoformatter
+      run: |
+        tox -e ruff
+        statusResult=$(git status -u --porcelain)
+        if [ -z statusResult ]
+        then
+            exit 0
+        else
+            echo "Source files are not formatted correctly. Run 'tox -e ruff' to autoformat."
+            exit 1
+        fi
+    - name: Run Linter
+      run: |
+        tox -e flake8
+
   build:
+    needs: lint
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
@@ -36,9 +64,6 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install setuptools wheel tox
-    - name: Run Linter
-      run: |
-        tox -e flake8
     - name: Check Typing
       run: |
         tox -e type