pr-test.yaml

name: PR Test
on:
  pull_request:
    type:
      - opened
      - synchronize
      - reopened

jobs:

  ref-depth:
    runs-on: ubuntu-latest
    outputs:
      depth: ${{ steps.depth.outputs.depth }}
    steps:
      - uses: actions/checkout@v3

      # Fetch history up to base
      - run: |
          git fetch origin ${{ github.event.pull_request.base.sha }}
          COMMITTER_DATE=`git show ${{ github.event.pull_request.base.sha }} --format="%cD" -s`
          git fetch --shallow-since="${COMMITTER_DATE}" origin

      # Determine required depth by comparing base to head, then adding 1
      - id: depth
        run: |
          COUNT=`git rev-list ${{ github.event.pull_request.base.sha }}..HEAD --count`
          echo "::set-output name=depth::$(($COUNT + 1))"

  build-and-test:
    needs: ref-depth
    uses: ./.github/workflows/build-and-test.yaml
    with:
      depth: ${{ fromJSON(needs.ref-depth.outputs.depth) }}
      base-ref: ${{ github.event.pull_request.base.sha }}
      head-ref: ${{ github.event.pull_request.head.sha }}