feat(trace): isolate chat runs

src/test/java/com/superbiz/agent/controller/ChatControllerTest.java

@@ -0,0 +1,32 @@
+package com.superbiz.agent.controller;
+
+import com.superbiz.agent.service.ChatService;
+import org.junit.jupiter.api.Test;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.util.ReflectionTestUtils;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verifyNoInteractions;
+
+class ChatControllerTest {
+
+    @Test
+    void blankChatRequestReturnsErrorBeforeCreatingRun() {
+        ChatController controller = new ChatController();
+        ChatService chatService = mock(ChatService.class);
+        ReflectionTestUtils.setField(controller, "chatService", chatService);
+
+        ChatController.ChatRequest request = new ChatController.ChatRequest();
+        request.setId("invalid-chat-session");
+        request.setQuestion("   ");
+
+        ResponseEntity<ChatController.ApiResponse<ChatController.ChatResponse>> response = controller.chat(request);
+
+        ChatController.ChatResponse body = response.getBody().getData();
+        assertFalse(body.isSuccess());
+        assertEquals("问题内容不能为空", body.getErrorMessage());
+        verifyNoInteractions(chatService);
+    }
+}