(rfc) chat models (#1424)

Co-authored-by: Ankush Gola <ankush.gola@gmail.com>

tests/integration_tests/chat_models/test_openai.py

@@ -0,0 +1,89 @@
+"""Test ChatOpenAI wrapper."""
+
+import pytest
+
+from langchain.callbacks.base import CallbackManager
+from langchain.chat_models.openai import ChatOpenAI
+from langchain.schema import (
+    BaseMessage,
+    ChatGeneration,
+    ChatResult,
+    HumanMessage,
+    LLMResult,
+    SystemMessage,
+)
+from tests.unit_tests.callbacks.fake_callback_handler import FakeCallbackHandler
+
+
+def test_chat_openai() -> None:
+    """Test ChatOpenAI wrapper."""
+    chat = ChatOpenAI(max_tokens=10)
+    message = HumanMessage(content="Hello")
+    response = chat([message])
+    assert isinstance(response, BaseMessage)
+    assert isinstance(response.content, str)
+
+
+def test_chat_openai_system_message() -> None:
+    """Test ChatOpenAI wrapper with system message."""
+    chat = ChatOpenAI(max_tokens=10)
+    system_message = SystemMessage(content="You are to chat with the user.")
+    human_message = HumanMessage(content="Hello")
+    response = chat([system_message, human_message])
+    assert isinstance(response, BaseMessage)
+    assert isinstance(response.content, str)
+
+
+def test_chat_openai_generate() -> None:
+    """Test ChatOpenAI wrapper with generate."""
+    chat = ChatOpenAI(max_tokens=10, n=2)
+    message = HumanMessage(content="Hello")
+    response = chat.generate([[message], [message]])
+    assert isinstance(response, LLMResult)
+    assert len(response.generations) == 2
+    for generations in response.generations:
+        assert len(generations) == 2
+        for generation in generations:
+            assert isinstance(generation, ChatGeneration)
+            assert isinstance(generation.text, str)
+            assert generation.text == generation.message.content
+
+
+def test_chat_openai_multiple_completions() -> None:
+    """Test ChatOpenAI wrapper with multiple completions."""
+    chat = ChatOpenAI(max_tokens=10, n=5)
+    message = HumanMessage(content="Hello")
+    response = chat._generate([message])
+    assert isinstance(response, ChatResult)
+    assert len(response.generations) == 5
+    for generation in response.generations:
+        assert isinstance(generation.message, BaseMessage)
+        assert isinstance(generation.message.content, str)
+
+
+def test_chat_openai_streaming() -> None:
+    """Test that streaming correctly invokes on_llm_new_token callback."""
+    callback_handler = FakeCallbackHandler()
+    callback_manager = CallbackManager([callback_handler])
+    chat = ChatOpenAI(
+        max_tokens=10,
+        streaming=True,
+        temperature=0,
+        callback_manager=callback_manager,
+        verbose=True,
+    )
+    message = HumanMessage(content="Hello")
+    response = chat([message])
+    assert callback_handler.llm_streams > 0
+    assert isinstance(response, BaseMessage)
+
+
+def test_chat_openai_invalid_streaming_params() -> None:
+    """Test that streaming correctly invokes on_llm_new_token callback."""
+    with pytest.raises(ValueError):
+        ChatOpenAI(
+            max_tokens=10,
+            streaming=True,
+            temperature=0,
+            n=5,
+        )