test_obj.py

#!/usr/bin/env python

from pytest import raises
from msgpack import packb, unpackb


def _decode_complex(obj):
    if b"__complex__" in obj:
        return complex(obj[b"real"], obj[b"imag"])
    return obj


def _encode_complex(obj):
    if isinstance(obj, complex):
        return {b"__complex__": True, b"real": 1, b"imag": 2}
    return obj


def test_encode_hook():
    packed = packb([3, 1 + 2j], default=_encode_complex)
    unpacked = unpackb(packed, use_list=1)
    assert unpacked[1] == {b"__complex__": True, b"real": 1, b"imag": 2}


def test_decode_hook():
    packed = packb([3, {b"__complex__": True, b"real": 1, b"imag": 2}])
    unpacked = unpackb(packed, object_hook=_decode_complex, use_list=1)
    assert unpacked[1] == 1 + 2j


def test_decode_pairs_hook():
    packed = packb([3, {1: 2, 3: 4}])
    prod_sum = 1 * 2 + 3 * 4
    unpacked = unpackb(
        packed,
        object_pairs_hook=lambda lst: sum(k * v for k, v in lst),
        use_list=1,
        strict_map_key=False,
    )
    assert unpacked[1] == prod_sum


def test_only_one_obj_hook():
    with raises(TypeError):
        unpackb(b"", object_hook=lambda x: x, object_pairs_hook=lambda x: x)


def test_bad_hook():
    with raises(TypeError):
        packed = packb([3, 1 + 2j], default=lambda o: o)
        unpackb(packed, use_list=1)


def _arr_to_str(arr):
    return "".join(str(c) for c in arr)


def test_array_hook():
    packed = packb([1, 2, 3])
    unpacked = unpackb(packed, list_hook=_arr_to_str, use_list=1)
    assert unpacked == "123"


class DecodeError(Exception):
    pass


def bad_complex_decoder(o):
    raise DecodeError("Ooops!")


def test_an_exception_in_objecthook1():
    with raises(DecodeError):
        packed = packb({1: {"__complex__": True, "real": 1, "imag": 2}})
        unpackb(packed, object_hook=bad_complex_decoder, strict_map_key=False)


def test_an_exception_in_objecthook2():
    with raises(DecodeError):
        packed = packb({1: [{"__complex__": True, "real": 1, "imag": 2}]})
        unpackb(packed, list_hook=bad_complex_decoder, use_list=1, strict_map_key=False)