test_runnable_branch_invoke_call_counts() — langchain Function Reference

Architecture documentation for the test_runnable_branch_invoke_call_counts() function in test_runnable.py from the langchain codebase.

Function python LangChainCore Runnables calls 1

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LangChainCore→ Runnables→ test_runnable_branch_invoke_call_counts() — langchain Function Reference

Dependency Diagram

graph TD
  38d73f31_4fab_d6b5_9f26_47973d8974fc["test_runnable_branch_invoke_call_counts()"]
  26df6ad8_0189_51d0_c3c1_6c3248893ff5["test_runnable.py"]
  38d73f31_4fab_d6b5_9f26_47973d8974fc -->|defined in| 26df6ad8_0189_51d0_c3c1_6c3248893ff5
  fb618d44_c03b_ea8b_385b_2278dfb173d4["invoke()"]
  38d73f31_4fab_d6b5_9f26_47973d8974fc -->|calls| fb618d44_c03b_ea8b_385b_2278dfb173d4
  style 38d73f31_4fab_d6b5_9f26_47973d8974fc fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/tests/unit_tests/runnables/test_runnable.py lines 4511–4536

def test_runnable_branch_invoke_call_counts(mocker: MockerFixture) -> None:
    """Verify that runnables are invoked only when necessary."""
    # Test with single branch
    add = RunnableLambda[int, int](lambda x: x + 1)
    sub = RunnableLambda[int, int](lambda x: x - 1)
    condition = RunnableLambda[int, bool](lambda x: x > 0)
    spy = mocker.spy(condition, "invoke")
    add_spy = mocker.spy(add, "invoke")

    branch = RunnableBranch[int, int]((condition, add), (condition, add), sub)
    assert spy.call_count == 0
    assert add_spy.call_count == 0

    assert branch.invoke(1) == 2
    assert add_spy.call_count == 1
    assert spy.call_count == 1

    assert branch.invoke(2) == 3
    assert spy.call_count == 2
    assert add_spy.call_count == 2

    assert branch.invoke(-3) == -4
    # Should fall through to default branch with condition being evaluated twice!
    assert spy.call_count == 4
    # Add should not be invoked
    assert add_spy.call_count == 2