fix: avoid null check exception in the analyzer

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 5.2.1
+
+* fix: avoid null check exception in the analyzer.
+
 ## 5.2.0
 
 * fix: remove recursive traversal for [`ban-name`](https://dartcodemetrics.dev/docs/rules/common/ban-name) rule.

lib/src/analyzers/unused_code_analyzer/used_code_visitor.dart

@@ -157,7 +157,8 @@ class UsedCodeVisitor extends RecursiveAstVisitor<void> {
   }
 
   bool _recordConditionalElement(Element element) {
-    final elementPath = element.source?.fullName;
+    // ignore: deprecated_member_use
+    final elementPath = element.enclosingElement3?.source?.fullName;
     if (elementPath == null) {
       return false;
     }