def test_read_file_return(mocker, get_sample):
data = get_sample('ifconfig.out')
mock_open = mocker.mock_open(read_data=data)
if PY2:
mocker.patch('__builtin__.open', mock_open)
else:
mocker.patch('builtins.open', mock_open)
assert getmac._read_file('ifconfig.out') == data
mock_open.assert_called_once_with('ifconfig.out')
def test_read_file_not_exist():
assert getmac._read_file('DOESNOTEXIST') is None