Trigger conflict-detection on push on main (#14479)

Author: koppor

.github/ghprcomment.yml

@@ -148,7 +148,7 @@
 
     In future, **please avoid that**. For now, you can continue working.
 - jobName: 'Conflicts with target branch'
-  workflowName: 'On PR opened/updated'
+  workflowName: 'On PR opened/updated (check)'
   message: >
     Your pull request conflicts with the target branch.
 

.github/workflows/on-pr-opened-updated-check.yml

@@ -5,27 +5,69 @@ on:
   pull_request_target:
   # default: opened, synchronize, reopened
 
+  workflow_dispatch:
+    inputs:
+      pr_number:
+        description: 'PR number'
+        required: true
+
 jobs:
   conflicts_with_target:
     if: github.repository == 'JabRef/jabref'
     name: Conflicts with target branch
     runs-on: ubuntu-latest
     permissions:
-      contents: read
       actions: write
+      contents: read
+      pull-requests: write
     steps:
       - uses: actions/checkout@v6
         with:
           show-progress: 'false'
       - name: Check PR mergeability
         id: check_mergeable
         run: |
-          MERGEABLE=$(gh pr view --json mergeable ${{ github.event.pull_request.number }} --template '{{.mergeable}}')
+          set -e
+          MERGEABLE=$(gh pr view --json mergeable $PR_NUMBER --template '{{.mergeable}}')
           if [ "$MERGEABLE" == "CONFLICTING" ]; then
             echo "❌ Merge conflicts"
-            gh issue --repo $REPO edit $PR_NUMBER --remove-label "status: ready-for-review" --add-label "status: changes-required"
+            echo "❌ Merge conflicts at PR [#$PR_NUMBER](https://github.com/JabRef/jabref/pull/$PR_NUMBER)" >> $GITHUB_STEP_SUMMARY
+            gh issue edit $PR_NUMBER --remove-label "status: ready-for-review" --add-label "status: changes-required"
+
+            # "workflow dispatch" does not trigger subsequent "on completion" runs
+            # Therefore, we emulate ghprcomment here
+            if [ "$EVENT" = "workflow_dispatch" ]; then
+              HAS_CONFLICT_COMMENT=$(gh api repos/jabref/JabRef/issues/$PR_NUMBER/comments | jq '.[].body | contains("Conflicts with target branch")' | grep true || true)
+
+              if [ -n "$HAS_CONFLICT_COMMENT" ]; then
+                echo "Already commented about conflicts."
+                # When triggered by another workflow, success is also if there is a merge conflict
+                exit 0;
+              fi
+
+              echo "Commenting on PR..."
+              cat > body.txt <<EOF
+          Your pull request conflicts with the target branch.
+
+          Please [merge `upstream/main`](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork#syncing-a-fork-branch-from-the-command-line) with your code. For a step-by-step guide to resolve merge conflicts, see <https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/addressing-merge-conflicts/resolving-a-merge-conflict-using-the-command-line>.
+
+          <!-- ghprcomment
+          On PR opened/updated (check)
+          Conflicts with target branch
+          -->
+          EOF
+              gh issue comment "$PR_NUMBER" --body-file body.txt
+              echo "Commented on PR" >> $GITHUB_STEP_SUMMARY
+
+              # When triggered by another workflow, success is also if there is a merge conflict
+              exit 0;
+            fi;
+
             exit 1
           fi
           echo "✅ No merge conflicts"
+          echo "✅ No merge conflicts at PR [#$PR_NUMBER](https://github.com/JabRef/jabref/pull/$PR_NUMBER)" >> $GITHUB_STEP_SUMMARY
         env:
+          EVENT: ${{ github.event_name }}
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          PR_NUMBER: ${{ github.event.pull_request.number || inputs.pr_number }}

.github/workflows/pr-comment.yml

@@ -8,7 +8,7 @@ name: Comment on PR
 on:
   workflow_run:
     # note when updating via a PR and testing - `workflow_run` executes from the `main` branch and not the PR branch
-    workflows: ["Source Code Tests", "On PR opened/updated", "Check PR Format", "Link PR to Issue", "Check PR Modifications", "Check PR CHANGELOG.md"]
+    workflows: ["Source Code Tests", "On PR opened/updated (check)", "Check PR Format", "Link PR to Issue", "Check PR Modifications", "Check PR CHANGELOG.md"]
     # https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#running-a-workflow-based-on-the-conclusion-of-another-workflow
     types: [completed]
   workflow_dispatch:

.github/workflows/rerun-merge-conflict-check.yml

@@ -0,0 +1,29 @@
+name: Rerun PR merge conclicts check
+
+on:
+  push:
+    branches:
+      - add-rerun
+  schedule:
+    - cron: "0 3 * * *"
+  workflow_dispatch:
+
+jobs:
+  rerun:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          show-progress: 'false'
+      - name: Trigger "On PR opened/updated (check)" for all open PRs
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          workflow_name="On PR opened/updated (check)"
+
+          gh pr list --state open --json number --jq '.[] | "\(.number)"' |
+          while read pr; do
+            echo "Triggering '$workflow_name' for PR #$pr"
+            gh workflow run "$workflow_name" --ref add-rerun --field pr_number="$pr"
+            echo "Triggered '$workflow_name' for PR [#$pr](https://github.com/JabRef/jabref/pull/$pr)" >> $GITHUB_STEP_SUMMARY
+          done