name: 'Get pull_request number for commit, if any'
description: 'Returns pull_request number or -1 if no pull_request associated with commit'
inputs:
  commit-sha:
    description: 'Commit SHA'
    required: true

outputs:
  pull-number:
    description: Pull request number
    value: ${{ steps.set-output.outputs.pull-number }}

runs:
  using: 'composite'
  steps:
    - uses: actions/checkout@v3

    - name: Fetch pull_request data associated with commit SHA
      uses: actions/github-script@v4
      id: fetch-pull-number-for-commit
      # assummption: we only care about the latest PR associated with the commit?
      with:
        script: |
          const { data } = await github.request(
            "GET /repos/{owner}/{repo}/commits/{commit_sha}/pulls",
            {
              owner: context.repo.owner,
              repo: context.repo.repo,
              commit_sha: '${{ inputs.commit-sha }}'
            })
          return data.length === 0 ? -1 : data[data.length-1].number

    - name: Set output
      id: set-output
      run: echo "::set-output name=pull-number::$PR_NUMBER"
      shell: bash
      env:
        PR_NUMBER: ${{ steps.fetch-pull-number-for-commit.outputs.result }}