Introduce python pre-commit

.github/workflows/ci.yml

@@ -31,6 +31,27 @@ jobs:
       PERSONAL_ACCESS_TOKEN: ${{ secrets.PERSONAL_ACCESS_TOKEN }}
     with:
       DRY_RUN: true
+  pre-commit:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: checkout
+      # From https://github.com/actions/checkout/issues/438#issuecomment-1114110354
+      # Required to fetch enough depth for diffs with master in the pre-commit step.
+      # Alternative is to use the checkout action with fetch-depth: 0, but that would
+      # fetch the whole history, potentially slowing down the CI pipeline.
+      run: |
+        commits=${{ github.event.pull_request.commits }}
+        if [[ -n "$commits" ]]; then
+          # Prepare enough depth for diffs with master
+          git fetch --depth="$(( commits + 1 ))"
+        fi
+    - uses: actions/setup-python@v3
+      with:
+          python-version: '3.11'
+    - uses: pre-commit/[email protected]
+      with:
+        extra_args: '--from-ref origin/master --to-ref ${{ github.sha }}'
   build:
     name: Build
     uses: dargmuesli/github-actions/.github/workflows/[email protected]

.pre-commit-config.yaml

@@ -0,0 +1,20 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v3.2.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-added-large-files
+  - repo: https://github.com/psf/black
+    rev: 24.8.0
+    hooks:
+      - id: black
+  - repo: https://github.com/pycqa/flake8
+    rev: '7.1.1'
+    hooks:
+      - id: flake8
+        language: python
+        language_version: python3.11

README.md

@@ -17,9 +17,22 @@ Digital replacement for the drinks tally list featuring a touchscreen, user mana
 docker compose -f docker-compose.dev.yml up
 ```
 
-- Reading mails via mailpit: http://localhost:8025/
+Reading mails via mailpit: http://localhost:8025/
 
+The project is using poetry. Install the dependencies with:
 
+```sh
+poetry install
+```
+
+Python `pre-commit` helps to detect and fix common issues before committing. Install the git hooks with:
+
+```sh
+pre-commit install
+```
+
+It is also being run in the CI pipeline. If you see any rules that don't make sense for us, feel free
+to adjust the `.pre-commit-config.yaml` file or comment out invocation in the `ci.yml` file.
 
 This project is deployed within the [drinks-touch_stack](https://github.com/flipdot/drinks-touch_stack/) in accordance to the [DargStack template](https://github.com/dargstack/dargstack_template/) to make deployment a breeze.