action.yml

name: 'Update Submodule'
description: 'This action creates a pull request in a parent repository to update one of its submodules.'

inputs:
  github-token:
    required: true
  submodule-path:
    required: true
  parent-repository:
    required: true
  parent-branch:
    required: true
runs:
  using: 'composite'
  steps:
    - name: Checkout parent repository
      uses: actions/checkout@v3
      with:
        fetch-depth: 0
        ref: ${{ inputs.parent-branch }}
        repository: ${{ inputs.parent-repository }}
        submodules: true
        token: ${{ inputs.github-token }}

    - name: Update submodule and create pull request if needed
      env:
        GH_TOKEN: ${{ inputs.github-token }}
      shell: bash
      run: |
        submodule_path=${{ inputs.submodule-path }}
        branch_name=sync/${submodule_path##*/}

        git config user.name 'vtisweden-bot[bot]'
        git config user.email 'vtisweden-bot[bot]@users.noreply.github.com'

        if gh pr list | cut -f 3 -d $'\t' | grep -q "^$branch_name$"
        then
          git checkout $branch_name
          create_pr=false
        else
          git checkout -b $branch_name
          create_pr=true
        fi

        git submodule update --remote -- ${{ inputs.submodule-path }}
        git add -- ${{ inputs.submodule-path }}

        if git status | grep -q "Changes to be committed"
        then
          git commit ${{ inputs.submodule-path }} -m"Update submodule ${{ inputs.submodule-path }}"
          git push --set-upstream origin $branch_name
        else
          create_pr=false
        fi

        if $create_pr
        then
          gh pr create --title "Update submodule ${{ inputs.submodule-path }}" --body "" --base "${{ inputs.parent-branch }}" --head "$branch_name"
        fi