stack overflow fixes

state_machine_exporter/src/test/java/click/kamil/springstatemachineexporter/ResolutionRobustnessTest.java

@@ -0,0 +1,91 @@
+package click.kamil.springstatemachineexporter;
+
+import click.kamil.springstatemachineexporter.ast.common.CodebaseContext;
+import org.eclipse.jdt.core.dom.CompilationUnit;
+import org.eclipse.jdt.core.dom.TypeDeclaration;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ResolutionRobustnessTest {
+
+    @Test
+    void testStackOverflowPreventionWithCyclicInheritance(@TempDir Path tempDir) throws IOException {
+        Path fooDir = tempDir.resolve("com/foo");
+        Files.createDirectories(fooDir);
+        // Cyclic inheritance: Config extends Config
+        Files.writeString(fooDir.resolve("Config.java"), 
+            "package com.foo;\n" +
+            "public class Config extends Config {\n" +
+            "    public void configure() {}\n" +
+            "}");
+
+        CodebaseContext context = new CodebaseContext();
+        context.scan(tempDir);
+
+        TypeDeclaration td = context.getTypeDeclaration("com.foo.Config");
+        assertThat(td).isNotNull();
+
+        // This should not throw StackOverflowError
+        boolean result = context.extendsStateMachineConfigurerAdapter(td);
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void testShadowingResolution(@TempDir Path tempDir) throws IOException {
+        // Package com.foo has a class Config
+        Path fooDir = tempDir.resolve("com/foo");
+        Files.createDirectories(fooDir);
+        Files.writeString(fooDir.resolve("Config.java"), "package com.foo; public class Config {}");
+
+        // Package com.bar also has a class Config
+        Path barDir = tempDir.resolve("com/bar");
+        Files.createDirectories(barDir);
+        Files.writeString(barDir.resolve("Config.java"), "package com.bar; public class Config {}");
+
+        // App class imports com.bar.Config
+        Path appDir = tempDir.resolve("com/app");
+        Files.createDirectories(appDir);
+        String appSource = "package com.app;\n" +
+                           "import com.bar.Config;\n" +
+                           "public class App extends Config {}";
+        Path appFile = appDir.resolve("App.java");
+        Files.writeString(appFile, appSource);
+
+        CodebaseContext context = new CodebaseContext();
+        context.scan(tempDir);
+
+        TypeDeclaration appTd = context.getTypeDeclaration("com.app.App");
+        assertThat(appTd).isNotNull();
+
+        // Resolution in App.java context should pick com.bar.Config due to import
+        TypeDeclaration resolvedTd = context.getTypeDeclaration("Config", (CompilationUnit) appTd.getRoot());
+        assertThat(context.getFqn(resolvedTd)).isEqualTo("com.bar.Config");
+    }
+
+    @Test
+    void testAmbiguityHandling(@TempDir Path tempDir) throws IOException {
+        // Two classes with same name in different packages, no imports in context
+        Files.createDirectories(tempDir.resolve("p1"));
+        Files.writeString(tempDir.resolve("p1/X.java"), "package p1; public class X {}");
+
+        Files.createDirectories(tempDir.resolve("p2"));
+        Files.writeString(tempDir.resolve("p2/X.java"), "package p2; public class X {}");
+
+        CodebaseContext context = new CodebaseContext();
+        context.scan(tempDir);
+
+        // Ambiguous simple name should return null to prevent incorrect resolution
+        TypeDeclaration td = context.getTypeDeclaration("X");
+        assertThat(td).isNull();
+
+        // Exact FQN should still work
+        assertThat(context.getTypeDeclaration("p1.X")).isNotNull();
+        assertThat(context.getTypeDeclaration("p2.X")).isNotNull();
+    }
+}