TestEscapingEfficiency Class — langchain Architecture

Source Code

libs/core/tests/unit_tests/load/test_secret_injection.py lines 317–363

class TestEscapingEfficiency:
    """Tests that escaping doesn't cause excessive nesting."""

    def test_no_triple_escaping(self) -> None:
        """Verify dumpd doesn't cause triple/multiple escaping."""
        h = HumanMessage(
            "Hello",
            additional_kwargs={"bar": [MALICIOUS_SECRET_DICT]},
        )
        a = AIMessage("foo", additional_kwargs={"bar": [dumpd(h)]})
        d = dumpd(a)

        serialized = json.dumps(d)
        # Count nested escape markers -
        # should be max 2 (one for HumanMessage, one for secret)
        # Not 3+ which would indicate re-escaping of already-escaped content
        escape_count = len(re.findall(r"__lc_escaped__", serialized))

        # The HumanMessage dict gets escaped (1), the secret inside gets escaped (1)
        # Total should be 2, not 4 (which would mean triple nesting)
        assert escape_count <= 2, (
            f"Found {escape_count} escape markers, expected <= 2. "
            f"This indicates unnecessary re-escaping.\n{serialized}"
        )

    def test_double_nesting_no_quadruple_escape(self) -> None:
        """Verify double dumpd nesting doesn't explode escape markers."""
        h = HumanMessage(
            "Hello",
            additional_kwargs={"secret": MALICIOUS_SECRET_DICT},
        )
        a = AIMessage("middle", additional_kwargs={"nested": [dumpd(h)]})
        outer = AIMessage("outer", additional_kwargs={"deep": [dumpd(a)]})
        d = dumpd(outer)

        serialized = json.dumps(d)
        escape_count = len(re.findall(r"__lc_escaped__", serialized))

        # Should be:
        # outer escapes middle (1),
        # middle escapes h (1),
        # h escapes secret (1) = 3
        # Not 6+ which would indicate re-escaping
        assert escape_count <= 3, (
            f"Found {escape_count} escape markers, expected <= 3. "
            f"This indicates unnecessary re-escaping."
        )