test_chat_prompt_message_placeholder_partial() — langchain Function Reference

Architecture documentation for the test_chat_prompt_message_placeholder_partial() function in test_chat.py from the langchain codebase.

Function python LangChainCore LanguageModelBase

Entity Profile

LangChainCore→ LanguageModelBase→ test_chat_prompt_message_placeholder_partial() — langchain Function Reference

Dependency Diagram

graph TD
  b2b11531_6d42_06ab_6a5c_ceaeb2bf7162["test_chat_prompt_message_placeholder_partial()"]
  00c8bbe0_a31c_1ac8_487a_bfd5a9d6b117["test_chat.py"]
  b2b11531_6d42_06ab_6a5c_ceaeb2bf7162 -->|defined in| 00c8bbe0_a31c_1ac8_487a_bfd5a9d6b117
  style b2b11531_6d42_06ab_6a5c_ceaeb2bf7162 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/tests/unit_tests/prompts/test_chat.py lines 1074–1089

def test_chat_prompt_message_placeholder_partial() -> None:
    prompt = ChatPromptTemplate([MessagesPlaceholder("history")])
    prompt = prompt.partial(history=[("system", "foo")])
    assert prompt.format_messages() == [SystemMessage(content="foo")]
    assert prompt.format_messages(history=[("system", "bar")]) == [
        SystemMessage(content="bar")
    ]

    prompt = ChatPromptTemplate(
        [
            MessagesPlaceholder("history", optional=True),
        ]
    )
    assert prompt.format_messages() == []
    prompt = prompt.partial(history=[("system", "foo")])
    assert prompt.format_messages() == [SystemMessage(content="foo")]