check-up-to-date.yml

name: Check if PR is up-to-date

on:
  pull_request:
    branches:
      - main  # Trigger on PRs targeting the main branch (change if necessary)

jobs:
  check-up-to-date:
    runs-on: ubuntu-latest

    steps:
    # Checkout the PR branch
    - name: Checkout PR branch
      uses: actions/checkout@v3
      with:
        fetch-depth: 0

    # Fetch the base branch (e.g., main) for comparison
    - name: Fetch base branch
      run: git fetch origin main

    # Compare the PR branch with the base branch
    - name: Check if PR is up-to-date
      run: |
        # Fetch and compare base and PR branch commits
        BASE_BRANCH="origin/main"
        PR_BRANCH=$(git rev-parse --abbrev-ref HEAD)
        
        # Check if the PR branch is behind the base branch
        BEHIND=$(git rev-list --count $PR_BRANCH..$BASE_BRANCH)
        
        if [ "$BEHIND" -ne 0 ]; then
          echo "::error::Your branch is behind the base branch by $BEHIND commit(s). Please pull the latest changes."
          exit 1
        else
          echo "Your branch is up-to-date."
        fi