def test_one_repr_empty(self) -> None:
        """The faulty empty string repr did trigger an unbound local error in _diff_text."""

        class A(str):
            def __repr__(self):
                return ""

        expl = callequal(A(), "")
        assert not expl
The faulty empty string repr did trigger an unbound local error in _diff_text.
testing/test_assertion.py