Add Litellm support (#1493)

tests/llms/test_litellm.py

@@ -0,0 +1,90 @@
+import pytest
+from unittest.mock import Mock, patch
+
+from mem0.llms import litellm
+
+@pytest.fixture
+def mock_litellm():
+    with patch('mem0.llms.litellm.litellm') as mock_litellm:
+        yield mock_litellm
+
+def test_generate_response_with_unsupported_model(mock_litellm):
+    llm = litellm.LiteLLM(model="unsupported-model")
+    messages = [{"role": "user", "content": "Hello"}]
+    
+    mock_litellm.supports_function_calling.return_value = False
+
+    with pytest.raises(ValueError, match="Model 'unsupported-model' in litellm does not support function calling."):
+        llm.generate_response(messages)
+
+
+def test_generate_response_without_tools(mock_litellm):
+    llm = litellm.LiteLLM()
+    messages = [
+        {"role": "system", "content": "You are a helpful assistant."},
+        {"role": "user", "content": "Hello, how are you?"}
+    ]
+    
+    mock_response = Mock()
+    mock_response.choices = [Mock(message=Mock(content="I'm doing well, thank you for asking!"))]
+    mock_litellm.completion.return_value = mock_response
+    mock_litellm.supports_function_calling.return_value = True
+
+    response = llm.generate_response(messages)
+
+    mock_litellm.completion.assert_called_once_with(
+        model="gpt-4o",
+        messages=messages
+    )
+    assert response == "I'm doing well, thank you for asking!"
+
+
+def test_generate_response_with_tools(mock_litellm):
+    llm = litellm.LiteLLM()
+    messages = [
+        {"role": "system", "content": "You are a helpful assistant."},
+        {"role": "user", "content": "Add a new memory: Today is a sunny day."}
+    ]
+    tools = [
+        {
+            "type": "function",
+            "function": {
+                "name": "add_memory",
+                "description": "Add a memory",
+                "parameters": {
+                    "type": "object",
+                    "properties": {
+                        "data": {"type": "string", "description": "Data to add to memory"}
+                    },
+                    "required": ["data"],
+                },
+            },
+        }
+    ]
+    
+    mock_response = Mock()
+    mock_message = Mock()
+    mock_message.content = "I've added the memory for you."
+    
+    mock_tool_call = Mock()
+    mock_tool_call.function.name = "add_memory"
+    mock_tool_call.function.arguments = '{"data": "Today is a sunny day."}'
+    
+    mock_message.tool_calls = [mock_tool_call]
+    mock_response.choices = [Mock(message=mock_message)]
+    mock_litellm.completion.return_value = mock_response
+    mock_litellm.supports_function_calling.return_value = True
+
+    response = llm.generate_response(messages, tools=tools)
+
+    mock_litellm.completion.assert_called_once_with(
+        model="gpt-4o",
+        messages=messages,
+        tools=tools,
+        tool_choice="auto"
+    )
+    
+    assert response["content"] == "I've added the memory for you."
+    assert len(response["tool_calls"]) == 1
+    assert response["tool_calls"][0]["name"] == "add_memory"
+    assert response["tool_calls"][0]["arguments"] == {'data': 'Today is a sunny day.'}