fix(chat): 拦截无依据的非业务问题

tests/test_chat_knowledge_context.py

@@ -1,7 +1,7 @@
 import pytest
 
 from review_agent.models import KnowledgeBaseDocument
-from review_agent.services import build_knowledge_context
+from review_agent.services import build_knowledge_context, send_message, stream_message
 
 
 pytestmark = pytest.mark.django_db
@@ -57,3 +57,67 @@ def test_build_knowledge_context_uses_full_document_when_name_matches(settings,
     assert "全文材料" in context
     assert "来源：用户知识库/孙之烨-260510.txt" in context
     assert "完整经历：曾组织技术分享并带队参加竞赛" in context
+
+
+def test_send_message_refuses_out_of_scope_answer_without_knowledge_context(monkeypatch, django_user_model):
+    from review_agent.models import Conversation
+
+    user = django_user_model.objects.create_user(username="owner", password="pass")
+    conversation = Conversation.objects.create(user=user, title="会话")
+    monkeypatch.setattr(
+        "review_agent.services.search_knowledge_base",
+        lambda query, n_results=5: {"query": query, "results": [], "error_message": ""},
+    )
+    monkeypatch.setattr(
+        "review_agent.services.generate_reply",
+        lambda *args, **kwargs: pytest.fail("out-of-scope answer without knowledge context must not call LLM"),
+    )
+
+    _, assistant_message = send_message(conversation, "孙之烨是谁")
+
+    assert "没有在当前启用的知识库材料中找到" in assistant_message.content
+    assert "与当前主营业务无关" in assistant_message.content
+
+
+def test_stream_message_refuses_out_of_scope_answer_without_knowledge_context(monkeypatch, django_user_model):
+    from review_agent.models import Conversation
+
+    user = django_user_model.objects.create_user(username="owner", password="pass")
+    conversation = Conversation.objects.create(user=user, title="会话")
+    monkeypatch.setattr(
+        "review_agent.services.search_knowledge_base",
+        lambda query, n_results=5: {"query": query, "results": [], "error_message": ""},
+    )
+    monkeypatch.setattr(
+        "review_agent.services.stream_reply",
+        lambda *args, **kwargs: pytest.fail("out-of-scope answer without knowledge context must not call streaming LLM"),
+    )
+    monkeypatch.setattr(
+        "review_agent.services.generate_reply",
+        lambda *args, **kwargs: pytest.fail("out-of-scope answer without knowledge context must not call fallback LLM"),
+    )
+
+    frames = list(stream_message(conversation, "给我一份红烧肉菜谱"))
+
+    assert any("没有在当前启用的知识库材料中找到" in frame for frame in frames)
+    assert any("与当前主营业务无关" in frame for frame in frames)
+    assert any("done" in frame for frame in frames)
+
+
+def test_business_question_without_knowledge_context_can_use_llm(monkeypatch, django_user_model):
+    from review_agent.models import Conversation
+
+    user = django_user_model.objects.create_user(username="owner", password="pass")
+    conversation = Conversation.objects.create(user=user, title="会话")
+    monkeypatch.setattr(
+        "review_agent.services.search_knowledge_base",
+        lambda query, n_results=5: {"query": query, "results": [], "error_message": ""},
+    )
+    monkeypatch.setattr(
+        "review_agent.services.generate_reply",
+        lambda *args, **kwargs: "注册检验报告通常用于证明产品性能符合要求。",
+    )
+
+    _, assistant_message = send_message(conversation, "注册检验报告有什么作用")
+
+    assert "注册检验报告" in assistant_message.content