FakeChain Class — langchain Architecture

Architecture documentation for the FakeChain class in test_stdout.py from the langchain codebase.

Class python

Entity Profile

Dependency Diagram

graph TD
  3b3bfe11_acb4_d9c3_69b8_a09187c9e744["FakeChain"]
  f3cef70e_11b0_61c9_7ec0_7308f4b45056["Chain"]
  3b3bfe11_acb4_d9c3_69b8_a09187c9e744 -->|extends| f3cef70e_11b0_61c9_7ec0_7308f4b45056
  e88cb48a_5344_bda0_2779_e219af1a998b["test_stdout.py"]
  3b3bfe11_acb4_d9c3_69b8_a09187c9e744 -->|defined in| e88cb48a_5344_bda0_2779_e219af1a998b
  9ab365f8_7def_5d28_1b30_f97d418c8afb["input_keys()"]
  3b3bfe11_acb4_d9c3_69b8_a09187c9e744 -->|method| 9ab365f8_7def_5d28_1b30_f97d418c8afb
  dafa871c_646a_5f3a_dc66_745a2520e6fd["output_keys()"]
  3b3bfe11_acb4_d9c3_69b8_a09187c9e744 -->|method| dafa871c_646a_5f3a_dc66_745a2520e6fd
  d4912d4b_1690_a42d_11f2_e8963097770c["_call()"]
  3b3bfe11_acb4_d9c3_69b8_a09187c9e744 -->|method| d4912d4b_1690_a42d_11f2_e8963097770c

Relationship Graph

Source Code

libs/langchain/tests/unit_tests/callbacks/test_stdout.py lines 11–34

class FakeChain(Chain):
    """Fake chain class for testing purposes."""

    be_correct: bool = True
    the_input_keys: list[str] = ["foo"]
    the_output_keys: list[str] = ["bar"]

    @property
    def input_keys(self) -> list[str]:
        """Input keys."""
        return self.the_input_keys

    @property
    def output_keys(self) -> list[str]:
        """Output key of bar."""
        return self.the_output_keys

    @override
    def _call(
        self,
        inputs: dict[str, str],
        run_manager: CallbackManagerForChainRun | None = None,
    ) -> dict[str, str]:
        return {"bar": "bar"}