Add build artifact verification and fix script error handling

- Add verification step to check build artifacts exist before measuring
- Remove unreachable return statement before process.exit(1)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: AbanoubGhadban

.github/workflows/bundle-size.yml

@@ -72,9 +72,25 @@ jobs:
       - name: Install base dependencies
         run: pnpm install --frozen-lockfile
 
-      - name: Build and measure base branch
+      - name: Build base branch
+        run: pnpm run build
+
+      - name: Verify build artifacts
+        run: |
+          missing=0
+          for pkg in react-on-rails react-on-rails-pro react-on-rails-pro-node-renderer; do
+            if ! ls packages/$pkg/lib/*.js >/dev/null 2>&1; then
+              echo "::error::Missing build artifacts in packages/$pkg/lib/"
+              missing=1
+            fi
+          done
+          if [ $missing -eq 1 ]; then
+            exit 1
+          fi
+          echo "All build artifacts verified"
+
+      - name: Measure base branch sizes
         run: |
-          pnpm run build
           pnpm exec size-limit --json > /tmp/base-sizes.json
           echo "Base branch sizes:"
           cat /tmp/base-sizes.json

scripts/bundle-size.mjs

@@ -88,7 +88,7 @@ function readJsonFileOrExit(filePath) {
     return readJsonFile(filePath);
   } catch (error) {
     console.error(`${colors.red}Error reading ${filePath}: ${error.message}${colors.reset}`);
-    return process.exit(1);
+    process.exit(1);
   }
 }