Resolve path bindings through static-imported helper methods.

When helper invocations have no receiver, look up single static imports and static star imports before giving up; add cross-package, chained-helper, and fail-closed expander regressions.

Co-authored-by: Cursor <cursoragent@cursor.com>

state_machine_exporter/src/main/java/click/kamil/springstatemachineexporter/analysis/service/EntryPointBindingExpander.java

@@ -603,22 +603,70 @@ public final class EntryPointBindingExpander {
         String helperName = helperInvocation.getName().getIdentifier();
         CompilationUnit compilationUnit = ownerMethod.getRoot() instanceof CompilationUnit cu ? cu : null;
         Expression receiver = helperInvocation.getExpression();
-        TypeDeclaration declaringType;
         if (receiver == null) {
-            ASTNode parent = ownerMethod.getParent();
-            if (!(parent instanceof TypeDeclaration typeDeclaration)) {
-                return null;
-            }
-            declaringType = typeDeclaration;
-        } else {
-            declaringType = resolveHelperDeclaringType(receiver, compilationUnit, context);
-            if (declaringType == null) {
-                return null;
+            MethodDeclaration ownerHelper = findInstanceHelperOnOwnerType(ownerMethod, helperName, context);
+            if (ownerHelper != null) {
+                return ownerHelper;
             }
+            return findStaticImportHelper(helperName, compilationUnit, context);
+        }
+        TypeDeclaration declaringType = resolveHelperDeclaringType(receiver, compilationUnit, context);
+        if (declaringType == null) {
+            return null;
         }
         return context.findMethodDeclaration(declaringType, helperName, true);
     }
 
+    private static MethodDeclaration findInstanceHelperOnOwnerType(
+            MethodDeclaration ownerMethod,
+            String helperName,
+            CodebaseContext context) {
+        ASTNode parent = ownerMethod.getParent();
+        if (!(parent instanceof TypeDeclaration typeDeclaration)) {
+            return null;
+        }
+        return context.findMethodDeclaration(typeDeclaration, helperName, true);
+    }
+
+    private static MethodDeclaration findStaticImportHelper(
+            String helperName,
+            CompilationUnit compilationUnit,
+            CodebaseContext context) {
+        if (compilationUnit == null || helperName == null || helperName.isBlank()) {
+            return null;
+        }
+        for (Object importObject : compilationUnit.imports()) {
+            if (!(importObject instanceof ImportDeclaration importDeclaration) || !importDeclaration.isStatic()) {
+                continue;
+            }
+            String importedName = importDeclaration.getName().getFullyQualifiedName();
+            if (importDeclaration.isOnDemand()) {
+                MethodDeclaration helper = findHelperOnType(importedName, helperName, context);
+                if (helper != null) {
+                    return helper;
+                }
+                continue;
+            }
+            if (!importedName.endsWith("." + helperName)) {
+                continue;
+            }
+            String className = importedName.substring(0, importedName.lastIndexOf('.'));
+            return findHelperOnType(className, helperName, context);
+        }
+        return null;
+    }
+
+    private static MethodDeclaration findHelperOnType(
+            String typeName,
+            String helperName,
+            CodebaseContext context) {
+        TypeDeclaration typeDeclaration = context.getTypeDeclaration(typeName);
+        if (typeDeclaration == null) {
+            return null;
+        }
+        return context.findMethodDeclaration(typeDeclaration, helperName, true);
+    }
+
     private static TypeDeclaration resolveHelperDeclaringType(
             Expression receiver,
             CompilationUnit compilationUnit,

state_machine_exporter/src/test/java/click/kamil/springstatemachineexporter/analysis/service/EntryPointBindingExpanderTest.java

@@ -687,4 +687,206 @@ class EntryPointBindingExpanderTest {
         assertThat(variants).extracting(map -> map.get("commandKey"))
                 .containsExactlyInAnyOrder("order.pay", "order.ship");
     }
+
+    @Test
+    void shouldExpandEventWhenParameterIsPassedThroughImportedCrossPackageHelper(@TempDir Path tempDir) throws Exception {
+        Files.createDirectories(tempDir.resolve("com/example/util"));
+        Files.writeString(tempDir.resolve("com/example/util/EventNormalizer.java"), """
+            package com.example.util;
+            public class EventNormalizer {
+                public static String normalize(String raw) {
+                    return raw.toUpperCase();
+                }
+            }
+            """);
+        Files.writeString(tempDir.resolve("com/example/OrderGateway.java"), """
+            package com.example;
+            import com.example.util.EventNormalizer;
+            public class OrderController {
+                OrderGateway gateway;
+                public void transition(String event) {
+                    gateway.trigger(event);
+                }
+            }
+            class OrderGateway {
+                void trigger(String event) {
+                    OrderEvent.valueOf(EventNormalizer.normalize(event));
+                }
+            }
+            enum OrderEvent { PAY, SHIP }
+            """);
+
+        CodebaseContext context = new CodebaseContext();
+        context.setResolveBindings(true);
+        context.scan(tempDir);
+
+        HeuristicCallGraphEngine engine = new HeuristicCallGraphEngine(context);
+        Map<String, List<click.kamil.springstatemachineexporter.analysis.model.CallEdge>> graph = engine.buildCallGraph();
+
+        EntryPoint entryPoint = EntryPoint.builder()
+                .className("com.example.OrderController")
+                .methodName("transition")
+                .name("POST /api/order/{event}")
+                .parameters(List.of(EntryPoint.Parameter.builder()
+                        .name("event")
+                        .type("String")
+                        .annotations(List.of("PathVariable"))
+                        .build()))
+                .build();
+
+        List<Map<String, String>> variants =
+                EntryPointBindingExpander.expandPathVariableBindings(entryPoint, context, graph);
+
+        assertThat(variants).extracting(map -> map.get("event"))
+                .containsExactlyInAnyOrder("PAY", "SHIP");
+    }
+
+    @Test
+    void shouldNotExpandWhenSingleArgHelperReturnsConstantInsteadOfForwarding(@TempDir Path tempDir) throws Exception {
+        String source = """
+            package com.example;
+            public class OrderController {
+                OrderGateway gateway;
+                public void transition(String event) {
+                    gateway.trigger(event);
+                }
+            }
+            class OrderGateway {
+                void trigger(String event) {
+                    OrderEvent.valueOf(spoof(event));
+                }
+                String spoof(String raw) {
+                    return "PAY";
+                }
+            }
+            enum OrderEvent { PAY, SHIP }
+            """;
+        Files.writeString(tempDir.resolve("App.java"), source);
+
+        CodebaseContext context = new CodebaseContext();
+        context.setResolveBindings(true);
+        context.scan(tempDir);
+
+        HeuristicCallGraphEngine engine = new HeuristicCallGraphEngine(context);
+        Map<String, List<click.kamil.springstatemachineexporter.analysis.model.CallEdge>> graph = engine.buildCallGraph();
+
+        EntryPoint entryPoint = EntryPoint.builder()
+                .className("com.example.OrderController")
+                .methodName("transition")
+                .name("POST /api/order/{event}")
+                .parameters(List.of(EntryPoint.Parameter.builder()
+                        .name("event")
+                        .type("String")
+                        .annotations(List.of("PathVariable"))
+                        .build()))
+                .build();
+
+        List<Map<String, String>> variants =
+                EntryPointBindingExpander.expandPathVariableBindings(entryPoint, context, graph);
+
+        assertThat(variants).isEmpty();
+    }
+
+    @Test
+    void shouldExpandEventWhenParameterIsPassedThroughStaticImportHelper(@TempDir Path tempDir) throws Exception {
+        Files.createDirectories(tempDir.resolve("com/example/util"));
+        Files.writeString(tempDir.resolve("com/example/util/EventNormalizer.java"), """
+            package com.example.util;
+            public class EventNormalizer {
+                public static String normalize(String raw) {
+                    return raw.toUpperCase();
+                }
+            }
+            """);
+        Files.writeString(tempDir.resolve("com/example/OrderGateway.java"), """
+            package com.example;
+            import static com.example.util.EventNormalizer.normalize;
+            public class OrderController {
+                OrderGateway gateway;
+                public void transition(String event) {
+                    gateway.trigger(event);
+                }
+            }
+            class OrderGateway {
+                void trigger(String event) {
+                    OrderEvent.valueOf(normalize(event));
+                }
+            }
+            enum OrderEvent { PAY, SHIP }
+            """);
+
+        CodebaseContext context = new CodebaseContext();
+        context.setResolveBindings(true);
+        context.scan(tempDir);
+
+        HeuristicCallGraphEngine engine = new HeuristicCallGraphEngine(context);
+        Map<String, List<click.kamil.springstatemachineexporter.analysis.model.CallEdge>> graph = engine.buildCallGraph();
+
+        EntryPoint entryPoint = EntryPoint.builder()
+                .className("com.example.OrderController")
+                .methodName("transition")
+                .name("POST /api/order/{event}")
+                .parameters(List.of(EntryPoint.Parameter.builder()
+                        .name("event")
+                        .type("String")
+                        .annotations(List.of("PathVariable"))
+                        .build()))
+                .build();
+
+        List<Map<String, String>> variants =
+                EntryPointBindingExpander.expandPathVariableBindings(entryPoint, context, graph);
+
+        assertThat(variants).extracting(map -> map.get("event"))
+                .containsExactlyInAnyOrder("PAY", "SHIP");
+    }
+
+    @Test
+    void shouldExpandEventWhenParameterIsPassedThroughChainedSingleArgHelpers(@TempDir Path tempDir) throws Exception {
+        String source = """
+            package com.example;
+            public class OrderController {
+                OrderGateway gateway;
+                public void transition(String event) {
+                    gateway.trigger(event);
+                }
+            }
+            class OrderGateway {
+                void trigger(String event) {
+                    OrderEvent.valueOf(toUpperCase(trim(event)));
+                }
+                String trim(String raw) {
+                    return raw.trim();
+                }
+                String toUpperCase(String raw) {
+                    return raw.toUpperCase();
+                }
+            }
+            enum OrderEvent { PAY, SHIP }
+            """;
+        Files.writeString(tempDir.resolve("App.java"), source);
+
+        CodebaseContext context = new CodebaseContext();
+        context.setResolveBindings(true);
+        context.scan(tempDir);
+
+        HeuristicCallGraphEngine engine = new HeuristicCallGraphEngine(context);
+        Map<String, List<click.kamil.springstatemachineexporter.analysis.model.CallEdge>> graph = engine.buildCallGraph();
+
+        EntryPoint entryPoint = EntryPoint.builder()
+                .className("com.example.OrderController")
+                .methodName("transition")
+                .name("POST /api/order/{event}")
+                .parameters(List.of(EntryPoint.Parameter.builder()
+                        .name("event")
+                        .type("String")
+                        .annotations(List.of("PathVariable"))
+                        .build()))
+                .build();
+
+        List<Map<String, String>> variants =
+                EntryPointBindingExpander.expandPathVariableBindings(entryPoint, context, graph);
+
+        assertThat(variants).extracting(map -> map.get("event"))
+                .containsExactlyInAnyOrder("PAY", "SHIP");
+    }
 }