Resolve path bindings through cross-class static helpers.

EntryPointBindingExpander follows single-arg normalize helpers declared on other types and accepts switch selectors wrapped by those helpers when extracting string case arms.

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

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

@@ -600,12 +600,43 @@ public final class EntryPointBindingExpander {
             MethodDeclaration ownerMethod,
             MethodInvocation helperInvocation,
             CodebaseContext context) {
-        ASTNode parent = ownerMethod.getParent();
-        if (!(parent instanceof TypeDeclaration typeDeclaration)) {
-            return null;
-        }
         String helperName = helperInvocation.getName().getIdentifier();
-        return context.findMethodDeclaration(typeDeclaration, helperName, true);
+        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;
+            }
+        }
+        return context.findMethodDeclaration(declaringType, helperName, true);
+    }
+
+    private static TypeDeclaration resolveHelperDeclaringType(
+            Expression receiver,
+            CompilationUnit compilationUnit,
+            CodebaseContext context) {
+        org.eclipse.jdt.core.dom.ITypeBinding binding = receiver.resolveTypeBinding();
+        if (binding != null) {
+            TypeDeclaration typeDeclaration = context.getTypeDeclaration(binding.getQualifiedName());
+            if (typeDeclaration != null) {
+                return typeDeclaration;
+            }
+        }
+        if (receiver instanceof QualifiedName qualifiedName) {
+            return context.getTypeDeclaration(qualifiedName.getFullyQualifiedName());
+        }
+        if (receiver instanceof SimpleName simpleName) {
+            return context.getTypeDeclaration(simpleName.getIdentifier(), compilationUnit);
+        }
+        return null;
     }
 
     private static boolean isTrivialSingleArgStringHelper(MethodDeclaration helper) {
@@ -668,13 +699,13 @@ public final class EntryPointBindingExpander {
         method.getBody().accept(new ASTVisitor() {
             @Override
             public boolean visit(SwitchStatement node) {
-                collectCasesFromSwitch(node.getExpression(), node.statements(), paramName, cases);
+                collectCasesFromSwitch(node.getExpression(), node.statements(), paramName, cases, method, context);
                 return super.visit(node);
             }
 
             @Override
             public boolean visit(SwitchExpression node) {
-                collectCasesFromSwitch(node.getExpression(), node.statements(), paramName, cases);
+                collectCasesFromSwitch(node.getExpression(), node.statements(), paramName, cases, method, context);
                 return super.visit(node);
             }
 
@@ -691,8 +722,10 @@ public final class EntryPointBindingExpander {
             Expression selector,
             List<?> statements,
             String paramName,
-            Set<String> cases) {
-        if (!(selector instanceof SimpleName simpleName) || !paramName.equals(simpleName.getIdentifier())) {
+            Set<String> cases,
+            MethodDeclaration ownerMethod,
+            CodebaseContext context) {
+        if (!switchSelectorReferencesParameter(selector, paramName, ownerMethod, context)) {
             return;
         }
         for (Object statementObj : statements) {
@@ -706,6 +739,20 @@ public final class EntryPointBindingExpander {
         }
     }
 
+    private static boolean switchSelectorReferencesParameter(
+            Expression selector,
+            String paramName,
+            MethodDeclaration ownerMethod,
+            CodebaseContext context) {
+        if (selector instanceof SimpleName simpleName) {
+            return paramName.equals(simpleName.getIdentifier());
+        }
+        if (ownerMethod != null && context != null && selector instanceof MethodInvocation invocation) {
+            return isSingleArgHelperForwardingParameter(invocation, paramName, ownerMethod, context);
+        }
+        return false;
+    }
+
     private static void collectCasesFromIfChain(IfStatement ifStatement, String paramName, Set<String> cases) {
         IfStatement current = ifStatement;
         while (current != null) {

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

@@ -579,4 +579,112 @@ class EntryPointBindingExpanderTest {
         assertThat(variants).extracting(map -> map.get("event"))
                 .containsExactlyInAnyOrder("PAY", "SHIP");
     }
+
+    @Test
+    void shouldExpandEventWhenParameterIsPassedThroughCrossClassStaticHelper(@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(EventNormalizer.normalize(event));
+                }
+            }
+            class EventNormalizer {
+                static String normalize(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");
+    }
+
+    @Test
+    void shouldExpandPathVariableFromSwitchOnCrossClassStaticHelper(@TempDir Path tempDir) throws Exception {
+        String source = """
+            package com.example;
+            public class GenericCommandController {
+                CommandGateway gateway;
+                public void execute(String commandKey) {
+                    gateway.executeViaMapper(commandKey);
+                }
+            }
+            class CommandGateway {
+                StringCommandMapper mapper;
+                void executeViaMapper(String commandKey) {
+                    mapper.fromString(commandKey);
+                }
+            }
+            class StringCommandMapper {
+                DomainCommand fromString(String commandKey) {
+                    return switch (CommandKeys.normalize(commandKey)) {
+                        case "order.pay" -> DomainCommand.ORDER_PAY;
+                        case "order.ship" -> DomainCommand.ORDER_SHIP;
+                        default -> throw new IllegalArgumentException(commandKey);
+                    };
+                }
+            }
+            class CommandKeys {
+                static String normalize(String raw) {
+                    return raw.trim();
+                }
+            }
+            enum DomainCommand { ORDER_PAY, ORDER_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.GenericCommandController")
+                .methodName("execute")
+                .name("POST /api/commands/{commandKey}")
+                .parameters(List.of(EntryPoint.Parameter.builder()
+                        .name("commandKey")
+                        .type("String")
+                        .annotations(List.of("PathVariable"))
+                        .build()))
+                .build();
+
+        List<Map<String, String>> variants =
+                EntryPointBindingExpander.expandPathVariableBindings(entryPoint, context, graph);
+
+        assertThat(variants).extracting(map -> map.get("commandKey"))
+                .containsExactlyInAnyOrder("order.pay", "order.ship");
+    }
 }