ci: add PR squash message checker

.github/workflows/conventional-commits.yml

@@ -10,8 +10,42 @@ jobs:
     name: Conventional Commits
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - name: Checkout the PR
+        uses: actions/checkout@v3
 
       - uses: webiny/action-conventional-commits@v1.3.0
         with:
-          allowed-commit-types: "feat,fix,docs,ci,test,refactor,chore"
+          allowed-commit-types: "feat,fix,docs,ci,test,refactor,chore"
+
+
+      - name: Validate PR merge type and commit message
+        id: validate
+        run: |
+          # Extract the PR body
+          PR_BODY=$(curl -s -H "Authorization: Bearer ${{ secrets.GITHUB_TOKEN }}" \
+                          https://api.github.com/repos/${{ github.repository }}/pulls/${{ github.event.number }} | jq -r .body)
+
+          # Check if the "Squash merge" checkbox is selected
+          if echo "$PR_BODY" | grep -q "\- \[x\] Squash merge"; then
+            echo "Squash merge selected."
+
+            # Extract the proposed commit message block
+            COMMIT_MESSAGE=$(echo "$PR_BODY" | sed -n '/## Proposed Commit Message/,/##/p' | sed '1d;$d')
+
+            if [ -z "$COMMIT_MESSAGE" ]; then
+              echo "Error: Proposed commit message block is empty."
+              exit 1
+            fi
+
+            # Check if the commit message follows the conventional commits format
+            if ! echo "$COMMIT_MESSAGE" | grep -E '^(feat|fix|docs|ci|test|refactor|chore)(\(.+\))?: .{1,72}$'; then
+              echo "Error: Commit message does not follow the conventional commits format."
+              exit 1
+            fi
+          else
+            echo "Squash merge not selected. Skipping commit message check."
+          fi
+          
+      - name: Fail if validation failed
+        if: steps.validate.outputs.result != 'success'
+        run: exit 1