Auto format code on non-protected branches.

.github/workflows/ruff-format.yml

@@ -0,0 +1,48 @@
+name: Automatically format the code with ruff
+on:
+  - push
+
+jobs:
+  ruff-format:
+    permissions:
+      contents: write
+      pull-requests: write
+    name: Format the code with ruff and push the changes
+    runs-on: ubuntu-latest
+    if: ! startsWith(github.ref, 'refs/tags/') && github.ref != 'refs/heads/main' && ! (startsWith(github.ref, 'refs/heads/') && endsWith(github.ref, '.x')) && ! startsWith(github.ref, 'refs/heads/release')
+    env:
+      GIT_COMMIT_MESSAGE: |
+        Format with ruff
+
+        See https://icalendar.readthedocs.io/en/stable/contribute/development.html#code-format
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          repository: ${{ github.event.pull_request.head.repo.full_name }}
+          ref: ${{ github.event.pull_request.head.ref }}
+          fetch-depth: 0
+      - name: Set up Python
+        uses: actions/setup-python@v6
+        with:
+          python-version: 3.14
+          cache: pip
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install . --group formatting
+      - name: Format the code with ruff
+        run: ruff format
+      - name: Format the code with ruff check
+        run: ruff check --fix
+      - name: Show the changes
+        run: |
+          git status
+          git diff
+          git config --local user.email "github-actions[bot]@users.noreply.github.com"
+          git config --local user.name "github-actions[bot]"
+          git commit -a -m "${GIT_COMMIT_MESSAGE}" || echo "No changes to commit"
+      - name: Push changes
+        uses: ad-m/github-push-action@v1.0.0
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          branch: ${{ github.ref_name }}

CHANGES.rst

@@ -27,7 +27,7 @@ We still recommend checking out the new features and giving feedback in the repo
 Minor changes
 ~~~~~~~~~~~~~
 
-- ...
+- Pull requests from remote forks are formatted automatically. :pr:`1208`
 
 Breaking changes
 ~~~~~~~~~~~~~~~~