test_chat_prompt_template_from_messages_using_message_classes() — langchain Function Reference

Source Code

libs/core/tests/unit_tests/prompts/test_chat.py lines 317–338

def test_chat_prompt_template_from_messages_using_message_classes() -> None:
    """Test creating a chat prompt template using message class tuples."""
    template = ChatPromptTemplate.from_messages(
        [
            (SystemMessage, "You are a helpful AI bot. Your name is {name}."),
            (HumanMessage, "Hello, how are you doing?"),
            (AIMessage, "I'm doing well, thanks!"),
            (HumanMessage, "{user_input}"),
        ]
    )

    expected = [
        SystemMessage(
            content="You are a helpful AI bot. Your name is Bob.", additional_kwargs={}
        ),
        HumanMessage(content="Hello, how are you doing?", additional_kwargs={}),
        AIMessage(content="I'm doing well, thanks!", additional_kwargs={}),
        HumanMessage(content="What is your name?", additional_kwargs={}),
    ]

    messages = template.format_messages(name="Bob", user_input="What is your name?")
    assert messages == expected