skip PR creation if PR is already open

Author: Philip Keicher

.github/workflows/sync_overleaf.yml

@@ -33,8 +33,21 @@ jobs:
           env:
             OVERLEAF_TOKEN: ${{ secrets.OVERLEAF_TOKEN }}
             GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        - name: create pull request
+        - name: check for existing PRs
+          id: check_for_existing_PRs
           if: steps.sync_overleaf.outputs.commitDiffCount > 0
+          run: |
+            prs=$(gh pr list \
+                --repo "$GITHUB_REPOSITORY" \
+                --head 'sync_overleaf' \
+                --base 'master' \
+                --json 'Merge sync_overleaf into master' \
+                --jq 'length')
+            if ((prs > 0)); then
+                echo "skip=true" >> "$GITHUB_OUTPUT"
+            fi
+        - name: create pull request
+          if: ((steps.sync_overleaf.outputs.commitDiffCount > 0) && (steps.check_for_existing_PRs.outputs.skip != 'true'))
           run: gh pr create -B master -H sync_overleaf --title 'Merge sync_overleaf into master' --body 'Created by Github action'
           env:
               GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}