Validate llm_config passed to ConversableAgent

Based on microsoft#1522, this commit implements the additional validation checks in
`ConversableAgent.`

Add the following validation and `raise ValueError` if:

 - The `llm_config` is `None` (validated in `ConversableAgent`).
 - The `llm_config` has no `model` specified and `config_list` is empty
   (validated in `OpenAIWrapper`).
 - The `config_list` has at least one entry, but not all the entries have
   the `model` is specified (validated in `OpenAIWrapper`).

The rest of the changes are code churn to adjust or add the test cases.

autogen/agentchat/assistant_agent.py

@@ -33,7 +33,7 @@ def __init__(
         self,
         name: str,
         system_message: Optional[str] = DEFAULT_SYSTEM_MESSAGE,
-        llm_config: Optional[Union[Dict, Literal[False]]] = None,
+        llm_config: Optional[Union[Dict, Literal[False]]] = False,
         is_termination_msg: Optional[Callable[[Dict], bool]] = None,
         max_consecutive_auto_reply: Optional[int] = None,
         human_input_mode: Optional[str] = "NEVER",

autogen/agentchat/conversable_agent.py

@@ -78,8 +78,8 @@ def __init__(
         human_input_mode: Optional[str] = "TERMINATE",
         function_map: Optional[Dict[str, Callable]] = None,
         code_execution_config: Union[Dict, Literal[False]] = False,
-        llm_config: Optional[Union[Dict, Literal[False]]] = None,
-        default_auto_reply: Optional[Union[str, Dict, None]] = "",
+        llm_config: Optional[Union[Dict, Literal[False]]] = False,
+        default_auto_reply: Union[str, Dict] = "",
         description: Optional[str] = None,
     ):
         """
@@ -121,7 +121,7 @@ def __init__(
                 Please refer to [OpenAIWrapper.create](/docs/reference/oai/client#create)
                 for available options.
                 To disable llm-based auto reply, set to False.
-            default_auto_reply (str or dict or None): default auto reply when no code execution or llm-based reply is generated.
+            default_auto_reply (str or dict): default auto reply when no code execution or llm-based reply is generated.
             description (str): a short description of the agent. This description is used by other agents
                 (e.g. the GroupChatManager) to decide when to call upon this agent. (Default: system_message)
         """

autogen/oai/client.py

@@ -365,7 +365,7 @@ def __init__(self, *, config_list: Optional[List[Dict[str, Any]]] = None, **base
                 if "model" in config:
                     model = config["model"]
                 if model is None or len(model) == 0:
-                    raise ValueError("Please specify a value for the 'model' in 'config_list'.")
+                    raise ValueError("Please specify a non-empty 'model' value for every item in 'config_list'.")
                 self._register_default_client(config, openai_config)  # could modify the config
                 self._config_list.append(
                     {**extra_kwargs, **{k: v for k, v in config.items() if k not in self.openai_kwargs}}

test/agentchat/test_conversable_agent.py

@@ -794,7 +794,7 @@ def test_register_for_llm_without_model_name():
         ConversableAgent(name="agent", llm_config={"config_list": [{"model": "", "api_key": ""}]})
         assert False, "Expected ConversableAgent to throw ValueError."
     except ValueError as e:
-        assert e.args[0] == "Please specify a value for the 'model' in 'config_list'."
+        assert e.args[0] == "Please specify a non-empty 'model' value for every item in 'config_list'."
 
 
 def test_register_for_execution():