Merge pull request #261741 from tweag/mergeable

    runs-on: ubuntu-latest

    steps:

      - name: Resolving the merge commit

        env:

          GH_TOKEN: ${{ github.token }}

        run: |

          if result=$(git ls-remote --exit-code ${{ github.event.pull_request.base.repo.clone_url }} refs/pull/${{ github.event.pull_request.number }}/merge 2>&1); then

            mergedSha=$(cut -f1 <<< "$result")

            echo "The PR appears to not have any conflicts, checking the merge commit $mergedSha"

          # This checks for mergeability of a pull request as recommended in

          # https://docs.github.com/en/rest/guides/using-the-rest-api-to-interact-with-your-git-database?apiVersion=2022-11-28#checking-mergeability-of-pull-requests

          while true; do

            echo "Checking whether the pull request can be merged"

            prInfo=$(gh api \

              -H "Accept: application/vnd.github+json" \

              -H "X-GitHub-Api-Version: 2022-11-28" \

              /repos/"$GITHUB_REPOSITORY"/pulls/${{ github.event.pull_request.number }})

            mergeable=$(jq -r .mergeable <<< "$prInfo")

            mergedSha=$(jq -r .merge_commit_sha <<< "$prInfo")

            if [[ "$mergeable" == "null" ]]; then

              # null indicates that GitHub is still computing whether it's mergeable

              # Wait a couple seconds before trying again

              echo "GitHub is still computing whether this PR can be merged, waiting 5 seconds before trying again"

              sleep 5

            else

              break

            fi

          done

          if [[ "$mergeable" == "true" ]]; then

            echo "The PR can be merged, checking the merge commit $mergedSha"

          else

            echo "The PR may have a merge conflict"

            echo "'git ls-remote' output was:"

            echo "$result"

            echo "The PR cannot be merged, it has a merge conflict"

            exit 1

          fi

          echo "mergedSha=$mergedSha" >> "$GITHUB_ENV"