From 74a4e66a330bd7bbc0fd043a0f56711dbbb78cec Mon Sep 17 00:00:00 2001
From: Kamil Patryk Kozakowski <kamil.p.kozakowski@gmail.com>
Date: Sat, 27 Jun 2026 20:09:14 +0200
Subject: [PATCH] update

---
 .../analysis/service/AbstractCallGraphEngine.java              | 3 +++
 .../analysis/service/JdtCallGraphEngine.java                   | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/state_machine_exporter/src/main/java/click/kamil/springstatemachineexporter/analysis/service/AbstractCallGraphEngine.java b/state_machine_exporter/src/main/java/click/kamil/springstatemachineexporter/analysis/service/AbstractCallGraphEngine.java
index 6cb62cd..435967b 100644
--- a/state_machine_exporter/src/main/java/click/kamil/springstatemachineexporter/analysis/service/AbstractCallGraphEngine.java
+++ b/state_machine_exporter/src/main/java/click/kamil/springstatemachineexporter/analysis/service/AbstractCallGraphEngine.java
@@ -629,6 +629,9 @@ public abstract class AbstractCallGraphEngine implements CallGraphEngine {
     }
 
     protected String resolveArgument(Expression expr) {
+        if (expr == null) {
+            return "null";
+        }
         if (expr instanceof LambdaExpression le) {
             ASTNode body = le.getBody();
             if (body instanceof Expression bodyExpr) {
diff --git a/state_machine_exporter/src/main/java/click/kamil/springstatemachineexporter/analysis/service/JdtCallGraphEngine.java b/state_machine_exporter/src/main/java/click/kamil/springstatemachineexporter/analysis/service/JdtCallGraphEngine.java
index 5e99222..a56074b 100644
--- a/state_machine_exporter/src/main/java/click/kamil/springstatemachineexporter/analysis/service/JdtCallGraphEngine.java
+++ b/state_machine_exporter/src/main/java/click/kamil/springstatemachineexporter/analysis/service/JdtCallGraphEngine.java
@@ -124,6 +124,9 @@ public class JdtCallGraphEngine extends AbstractCallGraphEngine {
 
     @Override
     protected String resolveArgument(org.eclipse.jdt.core.dom.Expression expr) {
+        if (expr == null) {
+            return "null";
+        }
         // Extract from constructor args (e.g., new CustomMessage(OrderEvent.PROCESS, ...))
         org.eclipse.jdt.core.dom.Expression unwrappedBuilder = unwrapMessageBuilder(expr);
         if (unwrappedBuilder != expr) {