def test_check_for_error_response_returns_none_on_normal_response(self):
serial_packet = module.SerialPacket(
command=0x20,
data_bytes_count=0x00,
data_bytes=b"",
**PREFIX_AND_ADDR_DEFAULTS,
)
assert module._check_for_error_response(serial_packet) is None
def test_check_for_error_response_identifies_echoed_command(self):
serial_packet = module.SerialPacket(
command=0x0F,
data_bytes_count=0x02,
data_bytes=b"\x03\x99",
**PREFIX_AND_ADDR_DEFAULTS,
)
with pytest.raises(module.ErrorResponse) as e:
module._check_for_error_response(serial_packet)
assert f"0x{0x99:02X}" in str(e.value)
def test_check_for_error_response_identifies_bad_command_error_type(self):
serial_packet = module.SerialPacket(
command=0x0F,
data_bytes_count=0x02,
data_bytes=b"\x01\x99",
**PREFIX_AND_ADDR_DEFAULTS,
)
with pytest.raises(module.ErrorResponse) as e:
module._check_for_error_response(serial_packet)
assert "Bad Command" in str(e.value)
def test_repr(self):
packet = module.SerialPacket(
prefix=0xCA,
device_address_msb=0x00,
device_address_lsb=0x01,
command=0x20,
data_bytes_count=0x03,
data_bytes=b"\x11\x02\x71",
checksum=0x57,
)
assert "0xCA 0x00 0x01 0x20 0x03 0x11 0x02 0x71 0x57" in repr(packet)
def test_returns_response_serial_packet_from_bytes(
self, mock_serial_and_response):
mock_command_packet = Mock()
mock_serial_and_response.return_value = b"\xCA\x00\x01\x20\x03\x11\x02\x71\x57"
actual = module.send_command(sentinel.port, mock_command_packet)
expected_response_packet = module.SerialPacket(
command=0x20,
data_bytes_count=0x03,
data_bytes=b"\x11\x02\x71",
**PREFIX_AND_ADDR_DEFAULTS,
)
assert actual == expected_response_packet
class TestSerialPacket:
@pytest.mark.parametrize(
"name, packet_bytes, expected_packet",
[
(
"packet with data bytes",
b"\xCA\x00\x01\x20\x03\x11\x02\x71\x57",
module.SerialPacket(
prefix=0xCA,
device_address_msb=0x00,
device_address_lsb=0x01,
command=0x20,
data_bytes_count=0x03,
data_bytes=b"\x11\x02\x71",
checksum=0x57,
),
),
(
"packet with no data bytes",
b"\xCA\x00\x01\x20\x00\xDE",
module.SerialPacket(
prefix=0xCA,
device_address_msb=0x00,
device_address_lsb=0x01,
command=0x20,
data_bytes_count=0x00,
data_bytes=b"",
checksum=0xDE,
),
),
],
)
def test_init_from_bytes(self, name, packet_bytes, expected_packet):
actual_packet = module.SerialPacket.from_bytes(packet_bytes)
assert actual_packet == expected_packet
@pytest.mark.parametrize(
"name, response_bytes",
[
("incorrect prefix", b"\xAA\x00\x01\x20\x04\x11\x02\x71\x57"),
("incorrect address msb", b"\xCA\x01\x01\x20\x04\x11\x02\x71\x57"),
("incorrect address lsb", b"\xCA\x00\x99\x20\x04\x11\x02\x71\x57"),
("data byte count mismatch",
b"\xCA\x00\x01\x20\x04\x11\x02\x71\x57"),
("incorrect checksum", b"\xCA\x00\x01\x20\x03\x11\x02\x71\x58"),
],
)
def test_init_from_bytes_raises_if_invalid(self, name, response_bytes):
with pytest.raises(ValueError):
module.SerialPacket.from_bytes(response_bytes)
@pytest.mark.parametrize(
"name, command, data_bytes, expected_packet",
[
(
"command with data bytes",
0x20,
b"\x11\x02\x71",
module.SerialPacket(
prefix=0xCA,
device_address_msb=0x00,
device_address_lsb=0x01,
command=0x20,
data_bytes_count=0x03,
data_bytes=b"\x11\x02\x71",
checksum=0x57,
),
),
(
"command with no data bytes",
0x20,
b"",
module.SerialPacket(
prefix=0xCA,
device_address_msb=0x00,
device_address_lsb=0x01,
command=0x20,
data_bytes_count=0x00,
data_bytes=b"",
checksum=0xDE,
),
),
],
)
def test_init_from_command(self, name, command, data_bytes,
expected_packet):
actual_packet = module.SerialPacket.from_command(command, data_bytes)
assert actual_packet == expected_packet
@pytest.mark.parametrize(
"packet_bytes",
[
b"\xCA\x00\x01\x20\x03\x11\x02\x71\x57",
b"\xCA\x00\x01\x20\x00\xDE",
b"\xCA\x00\x01\x00\x00\xFE",
b"\xCA\x00\x01\x09\x00\xF5",
b"\xCA\x00\x01\x20\x03\x11\x02\x71\x57",
b"\xCA\x00\x01\xF0\x02\x01\x2C\xDF",
b"\xCA\x00\x01\xF0\x03\x11\x01\x2C\xCD",
],
)
def test_init_from_bytes_round_trip_to_bytes(self, packet_bytes):
packet = module.SerialPacket.from_bytes(packet_bytes)
# hexlify to make error message more readable
assert hexlify(packet.to_bytes()) == hexlify(packet_bytes)
def test_str(self):
packet = module.SerialPacket(
prefix=0xCA,
device_address_msb=0x00,
device_address_lsb=0x01,
command=0x20,
data_bytes_count=0x03,
data_bytes=b"\x11\x02\x71",
checksum=0x57,
)
assert "0xCA 0x00 0x01 0x20 0x03 0x11 0x02 0x71 0x57" in str(packet)
def test_repr(self):
packet = module.SerialPacket(
prefix=0xCA,
device_address_msb=0x00,
device_address_lsb=0x01,
command=0x20,
data_bytes_count=0x03,
data_bytes=b"\x11\x02\x71",
checksum=0x57,
)
assert "0xCA 0x00 0x01 0x20 0x03 0x11 0x02 0x71 0x57" in repr(packet)