Update llm library web interface

api/tests/test_llm.py

@@ -244,3 +244,55 @@ class TestLLMModelAPI:
         response = client.post("/api/llm", json=data)
         assert response.status_code == 200
         assert response.json()["type"] == "embedding"
+
+    def test_preview_llm_model_success(self, client, sample_llm_model_data, monkeypatch):
+        """Test LLM preview endpoint returns model reply."""
+        from app.routers import llm as llm_router
+
+        create_response = client.post("/api/llm", json=sample_llm_model_data)
+        model_id = create_response.json()["id"]
+
+        class DummyResponse:
+            status_code = 200
+
+            def json(self):
+                return {
+                    "choices": [{"message": {"content": "Preview OK"}}],
+                    "usage": {"prompt_tokens": 10, "completion_tokens": 2, "total_tokens": 12}
+                }
+
+            @property
+            def text(self):
+                return '{"ok":true}'
+
+        class DummyClient:
+            def __init__(self, *args, **kwargs):
+                pass
+
+            def __enter__(self):
+                return self
+
+            def __exit__(self, exc_type, exc, tb):
+                return False
+
+            def post(self, url, json=None, headers=None):
+                assert url.endswith("/chat/completions")
+                assert headers["Authorization"] == f"Bearer {sample_llm_model_data['api_key']}"
+                assert json["messages"][0]["role"] == "user"
+                return DummyResponse()
+
+        monkeypatch.setattr(llm_router.httpx, "Client", DummyClient)
+
+        response = client.post(f"/api/llm/{model_id}/preview", json={"message": "hello"})
+        assert response.status_code == 200
+        data = response.json()
+        assert data["success"] is True
+        assert data["reply"] == "Preview OK"
+
+    def test_preview_llm_model_reject_empty_message(self, client, sample_llm_model_data):
+        """Test LLM preview endpoint validates message."""
+        create_response = client.post("/api/llm", json=sample_llm_model_data)
+        model_id = create_response.json()["id"]
+
+        response = client.post(f"/api/llm/{model_id}/preview", json={"message": "   "})
+        assert response.status_code == 400