Expand route maps from static factory methods with single Map.of return.

Follow one-return static factories that directly yield compile-time map literals for field initializers, static-block assignments, and putAll sources while failing closed on runtime-built maps or multiple returns.

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

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

@@ -638,6 +638,13 @@ public final class EntryPointBindingExpander {
         if (direct != null) {
             return direct;
         }
+        if (receiver instanceof MethodInvocation methodCall) {
+            Map<String, String> factory = extractCompileTimeMapFromStaticMethodCall(
+                    methodCall, literalDeclaringType, compilationUnit, context);
+            if (factory != null) {
+                return factory;
+            }
+        }
         String fieldName = null;
         TypeDeclaration declaringType = null;
         if (receiver instanceof FieldAccess fieldAccess) {
@@ -712,6 +719,12 @@ public final class EntryPointBindingExpander {
                         if (doubleBrace != null) {
                             return doubleBrace;
                         }
+                        CompilationUnit compilationUnit = typeDecl.getRoot() instanceof CompilationUnit cu ? cu : null;
+                        Map<String, String> factory = extractCompileTimeMapFromStaticMethodCall(
+                                initializer, typeDecl, compilationUnit, context);
+                        if (factory != null) {
+                            return factory;
+                        }
                     }
                     return extractStaticBlockMapPutEntries(typeDecl, fieldName, context);
                 }
@@ -773,6 +786,14 @@ public final class EntryPointBindingExpander {
                         foundPut[0] = true;
                         return super.visit(node);
                     }
+                    CompilationUnit compilationUnit = block.getRoot() instanceof CompilationUnit cu ? cu : null;
+                    Map<String, String> factory = extractCompileTimeMapFromStaticMethodCall(
+                            right, typeDecl, compilationUnit, context);
+                    if (factory != null) {
+                        entries.putAll(factory);
+                        foundPut[0] = true;
+                        return super.visit(node);
+                    }
                     if (right instanceof SimpleName localName
                             && mapBuilderLocals.contains(localName.getIdentifier())) {
                         linkedLocals.add(localName.getIdentifier());
@@ -945,6 +966,65 @@ public final class EntryPointBindingExpander {
         return false;
     }
 
+    private static Map<String, String> extractCompileTimeMapFromStaticMethodCall(
+            Expression expression,
+            TypeDeclaration defaultDeclaringType,
+            CompilationUnit compilationUnit,
+            CodebaseContext context) {
+        if (!(expression instanceof MethodInvocation invocation)) {
+            return null;
+        }
+        org.eclipse.jdt.core.dom.IMethodBinding binding = invocation.resolveMethodBinding();
+        if (binding == null || !Modifier.isStatic(binding.getModifiers())) {
+            return null;
+        }
+        TypeDeclaration declaringType = null;
+        if (binding.getDeclaringClass() != null) {
+            declaringType = context.getTypeDeclaration(binding.getDeclaringClass().getQualifiedName());
+        }
+        Expression receiver = invocation.getExpression();
+        if (declaringType == null && receiver != null) {
+            declaringType = resolveHelperDeclaringType(receiver, compilationUnit, context);
+        }
+        if (declaringType == null) {
+            declaringType = defaultDeclaringType;
+        }
+        if (declaringType == null) {
+            return null;
+        }
+        MethodDeclaration method = context.findMethodDeclaration(
+                declaringType, invocation.getName().getIdentifier(), true);
+        if (method == null || method.getBody() == null) {
+            return null;
+        }
+        Expression returnExpression = extractSingleReturnExpression(method.getBody());
+        if (returnExpression == null) {
+            return null;
+        }
+        Map<String, String> direct = extractMapOfLiteralEntries(returnExpression, declaringType, context);
+        if (direct != null) {
+            return direct;
+        }
+        return extractDoubleBraceMapPutEntries(returnExpression, declaringType, context);
+    }
+
+    private static Expression extractSingleReturnExpression(Block body) {
+        Expression[] found = {null};
+        boolean[] multiple = {false};
+        body.accept(new ASTVisitor() {
+            @Override
+            public boolean visit(ReturnStatement node) {
+                if (found[0] != null) {
+                    multiple[0] = true;
+                } else {
+                    found[0] = node.getExpression();
+                }
+                return super.visit(node);
+            }
+        });
+        return multiple[0] ? null : found[0];
+    }
+
     private static Map<String, String> extractMapOfLiteralEntries(
             Expression expression,
             TypeDeclaration declaringType,

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

@@ -4044,4 +4044,281 @@ class EntryPointBindingExpanderTest {
         assertThat(variants).extracting(map -> map.get("commandKey"))
                 .containsExactlyInAnyOrder("order.pay", "order.ship");
     }
+
+    @Test
+    void shouldExpandCommandKeyFromStaticFactoryMethodReturningMapOf(@TempDir Path tempDir) throws Exception {
+        String source = """
+            package com.example;
+            import java.util.Map;
+            public class GenericCommandController {
+                OrderGateway gateway;
+                public void execute(String commandKey) {
+                    gateway.trigger(commandKey);
+                }
+            }
+            class OrderGateway {
+                private static final Map<String, OrderEvent> ROUTES = routes();
+                static Map<String, OrderEvent> routes() {
+                    return Map.of(
+                        "order.pay", OrderEvent.PAY,
+                        "order.ship", OrderEvent.SHIP
+                    );
+                }
+                void trigger(String commandKey) {
+                    StateMachine sm = new StateMachine();
+                    sm.sendEvent(ROUTES.get(commandKey));
+                }
+            }
+            class StateMachine { void sendEvent(OrderEvent event) {} }
+            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.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");
+    }
+
+    @Test
+    void shouldExpandCommandKeyFromCrossClassStaticFactoryMethodReturningMapOf(@TempDir Path tempDir) throws Exception {
+        String source = """
+            package com.example;
+            import java.util.Map;
+            public class GenericCommandController {
+                OrderGateway gateway;
+                public void execute(String commandKey) {
+                    gateway.trigger(commandKey);
+                }
+            }
+            class OrderGateway {
+                private static final Map<String, OrderEvent> ROUTES = CommandRoutes.seed();
+                void trigger(String commandKey) {
+                    StateMachine sm = new StateMachine();
+                    sm.sendEvent(ROUTES.get(commandKey));
+                }
+            }
+            class CommandRoutes {
+                static Map<String, OrderEvent> seed() {
+                    return Map.of(
+                        "order.pay", OrderEvent.PAY,
+                        "order.ship", OrderEvent.SHIP
+                    );
+                }
+            }
+            class StateMachine { void sendEvent(OrderEvent event) {} }
+            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.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");
+    }
+
+    @Test
+    void shouldExpandCommandKeyFromStaticBlockStaticFactoryAssignment(@TempDir Path tempDir) throws Exception {
+        String source = """
+            package com.example;
+            import java.util.Map;
+            public class GenericCommandController {
+                OrderGateway gateway;
+                public void execute(String commandKey) {
+                    gateway.trigger(commandKey);
+                }
+            }
+            class OrderGateway {
+                private static final Map<String, OrderEvent> ROUTES;
+                static {
+                    ROUTES = routes();
+                }
+                static Map<String, OrderEvent> routes() {
+                    return Map.of(
+                        "order.pay", OrderEvent.PAY,
+                        "order.ship", OrderEvent.SHIP
+                    );
+                }
+                void trigger(String commandKey) {
+                    StateMachine sm = new StateMachine();
+                    sm.sendEvent(ROUTES.get(commandKey));
+                }
+            }
+            class StateMachine { void sendEvent(OrderEvent event) {} }
+            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.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");
+    }
+
+    @Test
+    void shouldNotExpandCommandKeyFromStaticFactoryBuildingMapAtRuntime(@TempDir Path tempDir) throws Exception {
+        String source = """
+            package com.example;
+            import java.util.HashMap;
+            import java.util.Map;
+            public class GenericCommandController {
+                OrderGateway gateway;
+                public void execute(String commandKey) {
+                    gateway.trigger(commandKey);
+                }
+            }
+            class OrderGateway {
+                private static final Map<String, OrderEvent> ROUTES = routes();
+                static Map<String, OrderEvent> routes() {
+                    Map<String, OrderEvent> built = new HashMap<>();
+                    built.put("order.pay", OrderEvent.PAY);
+                    built.put("order.ship", OrderEvent.SHIP);
+                    return built;
+                }
+                void trigger(String commandKey) {
+                    StateMachine sm = new StateMachine();
+                    sm.sendEvent(ROUTES.get(commandKey));
+                }
+            }
+            class StateMachine { void sendEvent(OrderEvent event) {} }
+            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.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).isEmpty();
+    }
+
+    @Test
+    void shouldNotExpandCommandKeyFromStaticFactoryWithMultipleReturns(@TempDir Path tempDir) throws Exception {
+        String source = """
+            package com.example;
+            import java.util.Map;
+            public class GenericCommandController {
+                OrderGateway gateway;
+                public void execute(String commandKey) {
+                    gateway.trigger(commandKey);
+                }
+            }
+            class OrderGateway {
+                private static final Map<String, OrderEvent> ROUTES = routes(true);
+                static Map<String, OrderEvent> routes(boolean full) {
+                    if (full) {
+                        return Map.of(
+                            "order.pay", OrderEvent.PAY,
+                            "order.ship", OrderEvent.SHIP
+                        );
+                    }
+                    return Map.of("order.pay", OrderEvent.PAY);
+                }
+                void trigger(String commandKey) {
+                    StateMachine sm = new StateMachine();
+                    sm.sendEvent(ROUTES.get(commandKey));
+                }
+            }
+            class StateMachine { void sendEvent(OrderEvent event) {} }
+            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.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).isEmpty();
+    }
 }