Improve REST path binding for enum path variables and valueOf

Treat enum @PathVariable parameters as internal triggers, expand multiple path placeholders via cartesian bindings, derive event cases from proven Enum.valueOf chains, and add enterprise HTML regression coverage.

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

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

@@ -198,4 +198,50 @@ class EntryPointBindingExpanderTest {
         assertThat(variants).extracting(map -> map.get("machineType"))
                 .containsExactlyInAnyOrder("ORDER", "DOCUMENT");
     }
+
+    @Test
+    void shouldExpandEventPathVariableFromPreservedEnumValueOfParam(@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(event.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");
+        assertThat(EntryPointBindingExpander.withResolvedPath(entryPoint, variants.get(0)).getName())
+                .isEqualTo("POST /api/order/PAY");
+    }
 }

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

@@ -35,6 +35,43 @@ class ExternalTriggerPolicyTest {
                 entryPoint, trigger, "com.example.Api.trigger", "event", null)).isTrue();
     }
 
+    @Test
+    void pathVariableEnumParameterShouldBeInternal(@TempDir Path tempDir) throws Exception {
+        String source = """
+            package com.example;
+            import org.springframework.web.bind.annotation.*;
+            public class Api {
+                @PostMapping("/api/order/{event}")
+                public void transition(@PathVariable OrderEvent event) {
+                    fire(event);
+                }
+                void fire(OrderEvent event) {}
+            }
+            enum OrderEvent { PAY, SHIP }
+            """;
+        Files.writeString(tempDir.resolve("Api.java"), source);
+        CodebaseContext context = new CodebaseContext();
+        context.scan(tempDir);
+
+        EntryPoint entryPoint = EntryPoint.builder()
+                .type(EntryPoint.Type.REST)
+                .name("POST /api/order/{event}")
+                .className("com.example.Api")
+                .methodName("transition")
+                .parameters(List.of(EntryPoint.Parameter.builder()
+                        .name("event")
+                        .type("com.example.OrderEvent")
+                        .annotations(List.of("PathVariable"))
+                        .build()))
+                .build();
+        TriggerPoint trigger = TriggerPoint.builder()
+                .event("event")
+                .build();
+
+        assertThat(ExternalTriggerPolicy.isExternalFromSource(
+                entryPoint, trigger, "com.example.Api.transition", "event", context)).isFalse();
+    }
+
     @Test
     void requestBodyEnumShouldBeInternal(@TempDir Path tempDir) throws Exception {
         String source = """