add litellm chat test

tests/litellm_test.py

@@ -0,0 +1,61 @@
+# -*- coding: utf-8 -*-
+"""litellm test"""
+import unittest
+from unittest.mock import patch, MagicMock
+
+import agentscope
+from agentscope.models import load_model_by_config_name
+
+
+class TestLiteLLMChatWrapper(unittest.TestCase):
+    """Test LiteLLM Chat Wrapper"""
+
+    def setUp(self) -> None:
+        self.api_key = "test_api_key.secret_key"
+        self.messages = [
+            {"role": "user", "content": "Hello, litellm!"},
+            {"role": "assistant", "content": "How can I assist you?"},
+        ]
+
+    @patch("agentscope.models.litellm_model.litellm")
+    def test_chat(self, mock_litellm: MagicMock) -> None:
+        """
+        Test chat"""
+        mock_response = MagicMock()
+        mock_response.model_dump.return_value = {
+            "choices": [
+                {"message": {"content": "Hello, this is a mocked response!"}},
+            ],
+            "usage": {
+                "prompt_tokens": 100,
+                "completion_tokens": 5,
+                "total_tokens": 105,
+            },
+        }
+        mock_response.choices[
+            0
+        ].message.content = "Hello, this is a mocked response!"
+
+        mock_litellm.completion.return_value = mock_response
+
+        agentscope.init(
+            model_configs={
+                "config_name": "test_config",
+                "model_type": "litellm_chat",
+                "model_name": "ollama/llama3:8b",
+                "api_key": self.api_key,
+            },
+        )
+
+        model = load_model_by_config_name("test_config")
+
+        response = model(
+            messages=self.messages,
+            api_base="http://localhost:11434",
+        )
+
+        self.assertEqual(response.text, "Hello, this is a mocked response!")
+
+
+if __name__ == "__main__":
+    unittest.main()