Function open

t/unit/conftest.py:718–733

Patch builtins.open so that it returns StringIO object. :param side_effect: Additional side effect for when the open context is entered. Example:: >>> with mock.open(io.BytesIO) as open_fh: ... something_opening_and_writing_bytes_to_a_file() ... self.a

(side_effect=None)

@contextmanager
def open(side_effect=None):
    """Patch builtins.open so that it returns StringIO object.
    :param side_effect: Additional side effect for when the open context
        is entered.
    Example::
        >>> with mock.open(io.BytesIO) as open_fh:
        ...     something_opening_and_writing_bytes_to_a_file()
        ...     self.assertIn(b'foo', open_fh.getvalue())
    """
    with patch('builtins.open') as open_:
        with _mock_context(open_) as context:
            if side_effect is not None:
                context.__enter__.side_effect = side_effect
            val = context.__enter__.return_value = WhateverIO()
            val.__exit__ = Mock()
            yield val


@contextmanager