test_filecallback() — langchain Function Reference

Architecture documentation for the test_filecallback() function in test_file.py from the langchain codebase.

Function python LangChainCore Runnables calls 1

Entity Profile

LangChainCore→ Runnables→ test_filecallback() — langchain Function Reference

Dependency Diagram

graph TD
  100acb5f_bd9c_a651_cfbb_009e1e585010["test_filecallback()"]
  208c1f71_5b87_0580_ea58_7fe3e9a67452["test_file.py"]
  100acb5f_bd9c_a651_cfbb_009e1e585010 -->|defined in| 208c1f71_5b87_0580_ea58_7fe3e9a67452
  dbd1329b_a843_29c6_04d5_0d55023c8909["strip_ansi()"]
  100acb5f_bd9c_a651_cfbb_009e1e585010 -->|calls| dbd1329b_a843_29c6_04d5_0d55023c8909
  style 100acb5f_bd9c_a651_cfbb_009e1e585010 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/langchain/tests/unit_tests/callbacks/test_file.py lines 47–71

def test_filecallback(tmp_path: pathlib.Path) -> None:
    """Test the file callback handler."""
    log1 = tmp_path / "output.log"
    handler = FileCallbackHandler(str(log1))
    chain_test = FakeChain(callbacks=[handler])
    chain_test.invoke({"foo": "bar"})
    handler.close()
    # Assert the output is as expected
    assert "Entering new FakeChain chain" in strip_ansi(log1.read_text())

    # Test using a callback manager
    log2 = tmp_path / "output2.log"

    with FileCallbackHandler(str(log2)) as handler_cm:
        chain_test = FakeChain(callbacks=[handler_cm])
        chain_test.invoke({"foo": "bar"})

    assert "Entering new FakeChain chain" in strip_ansi(log2.read_text())

    # Test passing via invoke callbacks
    log3 = tmp_path / "output3.log"

    with FileCallbackHandler(str(log3)) as handler_cm:
        chain_test.invoke({"foo": "bar"}, {"callbacks": [handler_cm]})
    assert "Entering new FakeChain chain" in strip_ansi(log3.read_text())