Use PR comments instead of GitHub annotations

Author: numbata

.github/workflows/danger.yml

@@ -15,7 +15,33 @@ jobs:
         ruby-version: 3.4
         bundler-cache: true
     - name: Run Danger
+      id: danger
       env:
         BASE_SHA: ${{ github.event.pull_request.base.sha }}
         HEAD_SHA: ${{ github.event.pull_request.head.sha }}
-      run: bundle exec danger dry_run --base=$BASE_SHA --head=$HEAD_SHA --verbose
+        DANGER_REPORT_PATH: danger_report.md
+      run: |
+        bundle exec danger dry_run --base=$BASE_SHA --head=$HEAD_SHA --verbose
+        # Check if report contains errors
+        if grep -q "### Errors" danger_report.md 2>/dev/null; then
+          echo "has_errors=true" >> $GITHUB_OUTPUT
+        fi
+    - name: Find existing comment
+      if: always()
+      uses: peter-evans/find-comment@v3
+      id: find-comment
+      with:
+        issue-number: ${{ github.event.pull_request.number }}
+        comment-author: 'github-actions[bot]'
+        body-includes: '## Danger Report'
+    - name: Post or update PR comment
+      if: always()
+      uses: peter-evans/create-or-update-comment@v4
+      with:
+        comment-id: ${{ steps.find-comment.outputs.comment-id }}
+        issue-number: ${{ github.event.pull_request.number }}
+        body-path: danger_report.md
+        edit-mode: replace
+    - name: Fail if errors found
+      if: steps.danger.outputs.has_errors == 'true'
+      run: exit 1

Dangerfile

@@ -30,34 +30,33 @@ end
   end
 end
 
-# Output as GitHub Actions annotations (since we can't post PR comments without token)
-# Using print instead of puts to avoid Danger's "You used puts" warning
-if ENV['GITHUB_ACTIONS']
-  violation_report[:errors].each do |v|
-    if v.file && v.line
-      print "::error file=#{v.file},line=#{v.line}::#{v.message}\n"
-    else
-      print "::error::#{v.message}\n"
-    end
+# Output markdown report for GitHub Actions to post as PR comment
+if ENV['DANGER_REPORT_PATH']
+  report = []
+  report << '## Danger Report'
+  report << ''
+
+  if violation_report[:errors].any?
+    report << '### Errors'
+    violation_report[:errors].each { |v| report << "- :no_entry_sign: #{v.message}" }
+    report << ''
   end
 
-  violation_report[:warnings].each do |v|
-    if v.file && v.line
-      print "::warning file=#{v.file},line=#{v.line}::#{v.message}\n"
-    else
-      print "::warning::#{v.message}\n"
-    end
+  if violation_report[:warnings].any?
+    report << '### Warnings'
+    violation_report[:warnings].each { |v| report << "- :warning: #{v.message}" }
+    report << ''
   end
 
-  violation_report[:messages].each do |v|
-    if v.file && v.line
-      print "::notice file=#{v.file},line=#{v.line}::#{v.message}\n"
-    else
-      print "::notice::#{v.message}\n"
-    end
+  if violation_report[:messages].any?
+    report << '### Messages'
+    violation_report[:messages].each { |v| report << "- :book: #{v.message}" }
+    report << ''
   end
 
-  # Debug: show counts
-  total = violation_report[:errors].count + violation_report[:warnings].count + violation_report[:messages].count
-  print "::notice::Danger completed: #{violation_report[:errors].count} errors, #{violation_report[:warnings].count} warnings, #{violation_report[:messages].count} messages\n"
+  if violation_report[:errors].empty? && violation_report[:warnings].empty? && violation_report[:messages].empty?
+    report << ':white_check_mark: All checks passed!'
+  end
+
+  File.write(ENV['DANGER_REPORT_PATH'], report.join("\n"))
 end