Implement exercise T6L1/branch-previous #327

	name: CI
	on:
	pull_request:
	branches:
	- main
	push:
	branches:
	- main
	workflow_dispatch:

	jobs:
	validate_exercise_configurations:
	runs-on: ubuntu-latest
	steps:
	- name: Checkout repository
	uses: actions/checkout@v4
	- name: Setup Python
	uses: actions/setup-python@v5
	with:
	python-version: "3.13"
	- name: Run validation script
	run: \|
	python validate-exercise-config.py

	unit_tests:
	runs-on: ubuntu-latest
	steps:
	- name: Checkout repository
	uses: actions/checkout@v4
	- name: Setup Python
	uses: actions/setup-python@v5
	with:
	python-version: "3.13"
	- name: Install dependencies
	run: \|
	pip install -r requirements.txt
	- name: Set up Git
	run: \|
	git config --global user.name "github-actions"
	git config --global user.email "github-actions@github.com"
	git config --global init.defaultBranch main
	- name: Run unit tests
	run: \|
	python -m pytest -s -vv

	format:
	runs-on: ubuntu-latest
	if: github.event_name == 'push' && github.ref == 'refs/heads/main'
	steps:
	- name: Checkout repository
	uses: actions/checkout@v4
	with:
	ref: main
	fetch-depth: 0
	- name: Setup Python
	uses: actions/setup-python@v5
	with:
	python-version: "3.13"
	- name: Install dependencies
	run: \|
	pip install -r requirements.txt
	- name: Run formatter using ruff
	run: \|
	ruff check --fix
	ruff format
	- name: Saving changes
	run: \|
	git config --global user.name "github-actions"
	git config --global user.email "github-actions@github.com"
	git config --global init.defaultBranch main
	git add .
	git diff-index --quiet HEAD \|\| git commit -m "[github-actions] Apply auto-formatting using ruff"
	git push

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