def test_Field__encode_mask__normal_one_byte():
"""
mask: 0b11110000
encoded: 0b00000011 <- input
shifted: 0b00110000 <- output
"""
f = Field("", bit_mask=0b11110000)
input_bytes = bytes([0b00000011])
expected = bytes([0b00110000])
actual = f._encode_mask(input_bytes)
assert actual == expected
def test_Field__encode_mask__normal_multi_byte():
"""
mask: 0x0FFFF0
encoded: 0x00FF00 <- input
shifted: 0x0FF000 <- output
"""
f = Field("", byte_index=(0, 1, 2), bit_mask=0x0FFFF0)
input_bytes = (0x00FF00).to_bytes(3, "big")
expected = (0x0FF000).to_bytes(3, "big")
actual = f._encode_mask(input_bytes)
assert actual == expected
def test_Field__encode_mask__condition_bit_mask_is_None():
f = Field("", bit_mask=None)
input_bytes = bytes(list(range(3)))
expected = input_bytes
actual = f._encode_mask(input_bytes)
assert actual == expected