def test_mapping(self):

_loader = mapping(str, optional(is_type(int) | float))

assert _loader({'sdfjk': 1}) == {'sdfjk': 1}

assert _loader({'a': 1, 'b': 2.4, 'c': None}) == {'a': 1, 'b': 2.4, 'c': None}

with pytest.raises(MappingError) as ei:

_loader({'a': 1, 345: 'sdjfhk', 'b': [], None: 389450})

err = ei.value

assert len(err.key_errors()) == 2

assert len(err.value_errors()) == 2

assert len(err.errors()) == 4

assert {key for key, _ in err.key_errors()} == {345, None}

assert {key for key, _ in err.value_errors()} == {345, 'b'}

with pytest.raises(TypeError):

_loader(1)

with pytest.raises(TypeError):

_loader([])

def test_mpfilter(self):

_loader = mpfilter(lambda k, v: k in {'a', 'b', 'sum'})

assert _loader({'a': 1, 'b': 2, 'sum': 3, 'sdk': 4}) == {'a': 1, 'b': 2, 'sum': 3}

def test_mpkeys(self):

_loader = mpkeys()

assert _loader({'a': 1, 'b': 2, 'sum': 3, 'sdk': 4}) == {'a', 'b', 'sum', 'sdk'}

def test_mpvalues(self):

_loader = mpvalues()

assert _loader({'a': 1, 'b': 2, 'sum': 3, 'sdk': 4}) == {1, 2, 3, 4}

def test_mpitems(self):

_loader = mpitems()

assert _loader({'a': 1, 'b': 2, 'sum': 3, 'sdk': 4}) == {('a', 1), ('b', 2), ('sum', 3), ('sdk', 4)}

def test_item(self):

_loader = item('a') | item('b')

assert _loader({'a': 1}) == 1

assert _loader({'b': 2}) == 2

assert _loader({'a': 3, 'b': -2}) == 3

def test_item_or(self):

_loader = item_or('a', 0)

assert _loader({'a': 1}) == 1