Class BadStringIO

IPython/utils/tests/test_io.py:69–73

        """IOStream initializes from a file-like object missing attributes. """
        # Cause a failure from getattr and dir(). (Issue #6386)
        class BadStringIO(StringIO):
            def __dir__(self):
                attrs = super().__dir__()
                attrs.append('name')
                return attrs
        with self.assertWarns(DeprecationWarning):
            iostream = IOStream(BadStringIO())
            iostream.write('hi, bad iostream\n')