test_sequential_application() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/implementations/test_pii.py lines 572–594

    def test_sequential_application(self) -> None:
        """Test that multiple PII types are detected when applied sequentially."""
        # First apply email middleware
        email_middleware = PIIMiddleware("email", strategy="redact")
        state = AgentState[Any](messages=[HumanMessage("Email: test@example.com, IP: 192.168.1.1")])
        result1 = email_middleware.before_model(state, Runtime())

        # Then apply IP middleware to the result
        ip_middleware = PIIMiddleware("ip", strategy="mask")
        assert result1 is not None
        state_with_email_redacted = AgentState[Any](messages=result1["messages"])
        result2 = ip_middleware.before_model(state_with_email_redacted, Runtime())

        assert result2 is not None
        content = result2["messages"][0].content

        # Email should be redacted
        assert "[REDACTED_EMAIL]" in content
        assert "test@example.com" not in content

        # IP should be masked
        assert "*.*.*.1" in content
        assert "192.168.1.1" not in content