test_tool_retry_succeeds_after_retries() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/implementations/test_tool_retry.py lines 287–325

def test_tool_retry_succeeds_after_retries() -> None:
    """Test ToolRetryMiddlewaresucceeds after temporary failures."""
    temp_fail = TemporaryFailureTool(fail_count=2)

    @tool
    def temp_failing_tool(value: str) -> str:
        """Tool that fails temporarily."""
        return temp_fail(value)

    model = FakeToolCallingModel(
        tool_calls=[
            [ToolCall(name="temp_failing_tool", args={"value": "test"}, id="1")],
            [],
        ]
    )

    retry = ToolRetryMiddleware(
        max_retries=3,
        initial_delay=0.01,
        jitter=False,
    )

    agent = create_agent(
        model=model,
        tools=[temp_failing_tool],
        middleware=[retry],
        checkpointer=InMemorySaver(),
    )

    result = agent.invoke(
        {"messages": [HumanMessage("Use temp failing tool")]},
        {"configurable": {"thread_id": "test"}},
    )

    tool_messages = [m for m in result["messages"] if isinstance(m, ToolMessage)]
    assert len(tool_messages) == 1
    # Should succeed on 3rd attempt
    assert "Success after 3 attempts" in tool_messages[0].content
    assert tool_messages[0].status != "error"