test_apply_to_tool_results_block_strategy() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/implementations/test_pii.py lines 474–495

    def test_apply_to_tool_results_block_strategy(self) -> None:
        """Test that block strategy raises error for PII in tool results."""
        middleware = PIIMiddleware(
            "email", strategy="block", apply_to_input=False, apply_to_tool_results=True
        )

        state = AgentState[Any](
            messages=[
                HumanMessage("Search for user"),
                AIMessage(
                    content="",
                    tool_calls=[ToolCall(name="search", args={}, id="call_789", type="tool_call")],
                ),
                ToolMessage(content="User email: sensitive@example.com", tool_call_id="call_789"),
            ]
        )

        with pytest.raises(PIIDetectionError) as exc_info:
            middleware.before_model(state, Runtime())

        assert exc_info.value.pii_type == "email"
        assert len(exc_info.value.matches) == 1