Abort if resulting pull would end up with no changes

.github/workflows/automerge.yml

@@ -26,14 +26,16 @@ jobs:
           git add package.json
           git -c user.name="GitHub" -c user.email="[email protected]" commit --author="github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>" -m"Fix package.json" | sed -n 1p || true
           git push
-          if [[ $(git status --porcelain | tee /dev/stderr | head -c1 | wc -c) -ne 0 || $(git clean -dffx | tee /dev/stderr | head -c1 | wc -c) -ne 0 ]]; then
-            exit 1
+          if [[ $(git diff --stat "$(git log -1 --skip=2 --format=%H)" "$(git log -1 --format=%H)") -eq 0 ]]; then
+            echo "automerge_pull_action=close" >> "$GITHUB_ENV"
+            exit 0
           fi
+          echo "automerge_pull_action=merge" >> "$GITHUB_ENV"
         fi
   automerge:
     runs-on: ubuntu-latest
     needs: package_json
-    if: ${{ github.actor == 'dependabot[bot]' && needs.package_json.result == 'success' }}
+    if: ${{ needs.package_json.result == 'success' && github.actor == 'dependabot[bot]' && env.automerge_pull_action == 'merge' }}
     steps:
     - name: automerge
       uses: actions/[email protected]
@@ -48,10 +50,9 @@ jobs:
   close:
     runs-on: ubuntu-latest
     needs: package_json
-    if: ${{ github.actor == 'renovate[bot]' && needs.package_json.result == 'success' }}
+    if: ${{ needs.package_json.result == 'success' && (github.actor == 'renovate[bot]' || (github.actor == 'dependabot[bot]' && env.automerge_pull_action == 'close')) }}
     steps:
     - name: Close Pull
       uses: peter-evans/[email protected]
-      continue-on-error: true
       with:
         delete-branch: true