def test_output_wiht_crc(self):
""" Test crc and is_crc functions. """
field = Field.crc()
self.assertEqual('crc', field.name)
self.assertTrue(Field.is_crc(field))
field = Field.padding(1)
self.assertFalse(Field.is_crc(field))
def __check_crc(cmd, result, extended_crc=False):
# type: (MasterCommandSpec, Result, bool) -> bool
""" Calculate the CRC of the data for a certain master command.
:param cmd: instance of MasterCommandSpec.
:param result: A dict containing the result of the master command.
:param extended_crc: Indicates whether the action should be included in the crc
:returns: boolean
"""
crc = 0
if extended_crc:
crc += cmd.action[0]
crc += cmd.action[1]
for field in cmd.output_fields:
if Field.is_crc(field):
break
else:
for byte in field.encode(result[field.name]):
crc += byte
return result['crc'] == bytearray([67, (crc // 256), (crc % 256)])