action.yml

name: 'PR Up to Date'
description: 'Check if branches are up to date and merge the base branch into the pull request branch if necessary.'

inputs:
  baseBranch:
    required: true
    description: 'The base branch to compare and merge.'

runs:
  using: 'composite'
  steps:
    - name: Checkout
      uses: actions/checkout@v2

    - uses: fregante/setup-git-user@v2

    - name: Fetch branches and update working directory
      shell: bash
      run: |
        git fetch origin ${{ github.event.pull_request.head.ref }}
        git fetch origin ${{ github.event.pull_request.base.ref }}

    - name: Check if branches are up to date
      shell: bash
      id: checkBranches
      run: |
        git checkout ${{ github.event.pull_request.head.ref }}
        BASE=$(git merge-base origin/${{ github.event.pull_request.base.ref }} HEAD)
        if [ $BASE = $(git rev-parse origin/${{ github.event.pull_request.base.ref }}) ]; then
          echo "Branches are up to date, skipping merge."
          echo "::set-output name=mergeRequired::false"
        else
          echo "Branches are not up to date, merge is required."
          echo "::set-output name=mergeRequired::true"
        fi

    - name: Merge base branch into PR branch
      shell: bash
      if: steps.checkBranches.outputs.mergeRequired == 'true'
      run: |
        git merge --no-edit --no-commit origin/${{ github.event.pull_request.base.ref }}
        if [ $? -ne 0 ]; then
          echo "Merge conflict detected. Please resolve conflicts before merging."
          exit 1
        fi
        git commit -m "Merge ${{ github.event.pull_request.base.ref }} into ${{ github.event.pull_request.head.ref }}"

    - name: Push changes
      shell: bash
      if: steps.checkBranches.outputs.mergeRequired == 'true'
      run: |
        git push origin ${{ github.event.pull_request.head.ref }}

branding:
  icon: 'git-pull-request'
  color: 'blue'