def test_structuring_unsupported():
"""Loading unsupported classes should throw."""
converter = Converter()
with raises(ValueError):
converter.structure(1, Converter)
with raises(ValueError):
converter.structure(1, Union[int, str])
def test_structuring_optional_primitives(primitive_and_type):
"""Test structuring Optional primitive types."""
converter = Converter()
val, type = primitive_and_type
assert converter.structure(val, Optional[type]) == val
assert converter.structure(None, Optional[type]) is None
def test_structuring_lists_of_opt(list_and_type):
"""Test structuring lists of Optional primitive types."""
converter = Converter()
l, t = list_and_type
l.append(None)
args = t.__args__
is_optional = args[0] is Optional or (is_union_type(args[0])
and len(args[0].__args__) == 2
and args[0].__args__[1] is NoneType)
if not is_bare(t) and (args[0] not in (Any, str) and not is_optional):
with raises((TypeError, ValueError)):
converter.structure(l, t)
optional_t = Optional[args[0]]
# We want to create a generic type annotation with an optional
# type parameter.
t = change_type_param(t, optional_t)
converted = converter.structure(l, t)
for x, y in zip(l, converted):
assert x == y
t.__args__ = args
def test_union_field_roundtrip(cl_and_vals_a, cl_and_vals_b, strat):
"""
Classes with union fields can be unstructured and structured.
"""
converter = Converter(unstruct_strat=strat)
cl_a, vals_a = cl_and_vals_a
cl_b, vals_b = cl_and_vals_b
a_field_names = {a.name for a in fields(cl_a)}
b_field_names = {a.name for a in fields(cl_b)}
assume(a_field_names)
assume(b_field_names)
common_names = a_field_names & b_field_names
assume(len(a_field_names) > len(common_names))
@attr.s
class C(object):
a = attr.ib(type=Union[cl_a, cl_b])
inst = C(a=cl_a(*vals_a))
if strat is UnstructureStrategy.AS_DICT:
assert inst == converter.structure(converter.unstructure(inst), C)
else:
# Our disambiguation functions only support dictionaries for now.
with pytest.raises(ValueError):
converter.structure(converter.unstructure(inst), C)
def handler(obj, _):
return converter.structure(obj, cl_a)
converter.register_structure_hook(Union[cl_a, cl_b], handler)
assert inst == converter.structure(converter.unstructure(inst), C)
def test_simple_roundtrip_defaults(cls_and_vals, strat):
"""
Simple classes with metadata can be unstructured and restructured.
"""
a, _ = cls_and_vals
cl = make_class("HypClass", {"a": a})
converter = Converter(unstruct_strat=strat)
inst = cl()
assert converter.unstructure(converter.structure(
{}, cl)) == converter.unstructure(inst)
assert inst == converter.structure(converter.unstructure(inst), cl)
def test_structuring_unsupported():
"""Loading unsupported classes should throw."""
converter = Converter()
with raises(StructureHandlerNotFoundError) as exc:
converter.structure(1, Converter)
assert exc.value.type_ is Converter
with raises(StructureHandlerNotFoundError) as exc:
converter.structure(1, Union[int, str])
assert exc.value.type_ is Union[int, str]
def test_structuring_seqs(seq_and_type):
"""Test structuring sequence generic types."""
converter = Converter()
iterable, t = seq_and_type
converted = converter.structure(iterable, t)
for x, y in zip(iterable, converted):
assert x == y
def test_renaming(cl_and_vals, data):
converter = Converter()
cl, vals = cl_and_vals
attrs = fields(cl)
to_replace = data.draw(sampled_from(attrs))
u_fn = make_dict_unstructure_fn(
cl, converter, **{to_replace.name: override(rename="class")}
)
s_fn = make_dict_structure_fn(
cl, converter, **{to_replace.name: override(rename="class")}
)
converter.register_structure_hook(cl, s_fn)
converter.register_unstructure_hook(cl, u_fn)
inst = cl(*vals)
raw = converter.unstructure(inst)
assert "class" in raw
new_inst = converter.structure(raw, cl)
assert inst == new_inst
def test_simple_roundtrip(cls_and_vals, strat):
"""
Simple classes with metadata can be unstructured and restructured.
"""
converter = Converter(unstruct_strat=strat)
cl, vals = cls_and_vals
inst = cl(*vals)
assert inst == converter.structure(converter.unstructure(inst), cl)
def test_stringifying_dicts(dict_and_type):
converter = Converter()
d, t = dict_and_type
converted = converter.structure(d, Dict[str, str])
for k, v in d.items():
assert converted[str(k)] == str(v)
def test_structuring_dicts(dict_and_type):
converter = Converter()
d, t = dict_and_type
converted = converter.structure(d, t)
assert converted == d
assert converted is not d
def test_nested_roundtrip(cls_and_vals, strat):
"""
Nested classes with metadata can be unstructured and restructured.
"""
converter = Converter(unstruct_strat=strat)
cl, vals = cls_and_vals
# Vals are a tuple, convert into a dictionary.
inst = cl(*vals)
assert inst == converter.structure(converter.unstructure(inst), cl)
def test_optional_field_roundtrip(cl_and_vals):
"""
Classes with optional fields can be unstructured and structured.
"""
converter = Converter()
cl, vals = cl_and_vals
@attr.s
class C(object):
a = attr.ib(type=Optional[cl])
inst = C(a=cl(*vals))
assert inst == converter.structure(converter.unstructure(inst), C)
inst = C(a=None)
unstructured = converter.unstructure(inst)
assert inst == converter.structure(unstructured, C)
def test_310_optional_field_roundtrip(cl_and_vals):
"""
Classes with optional fields can be unstructured and structured.
"""
converter = Converter()
cl, vals = cl_and_vals
@define
class C:
a: cl | None
inst = C(a=cl(*vals))
assert inst == converter.structure(converter.unstructure(inst), C)
inst = C(a=None)
unstructured = converter.unstructure(inst)
assert inst == converter.structure(unstructured, C)
def test_structuring_sets(set_and_type, set_type):
"""Test structuring generic sets."""
converter = Converter()
set_, input_set_type = set_and_type
if input_set_type not in (Set, FrozenSet, MutableSet):
set_type = set_type[input_set_type.__args__[0]]
converted = converter.structure(set_, set_type)
assert converted == set_
# Set[int] can't be used with isinstance any more.
non_generic = (set_type.__origin__
if set_type.__origin__ is not None else set_type)
assert isinstance(converted, non_generic)
converted = converter.structure(set_, Any)
assert converted == set_
assert isinstance(converted, type(set_))
def test_subclass_registration_is_honored():
"""If a subclass is registered after a superclass,
that subclass handler should be dispatched for
structure
"""
converter = Converter()
class Foo(object):
def __init__(self, value):
self.value = value
class Bar(Foo):
pass
converter.register_structure_hook(Foo, lambda obj, cls: cls("foo"))
assert converter.structure(None, Foo).value == "foo"
assert converter.structure(None, Bar).value == "foo"
converter.register_structure_hook(Bar, lambda obj, cls: cls("bar"))
assert converter.structure(None, Foo).value == "foo"
assert converter.structure(None, Bar).value == "bar"
def test_structuring_dicts_opts(dict_and_type, data):
"""Structure dicts, but with optional primitives."""
converter = Converter()
d, t = dict_and_type
assume(not is_bare(t))
t.__args__ = (t.__args__[0], Optional[t.__args__[1]])
d = {k: v if data.draw(booleans()) else None for k, v in d.items()}
converted = converter.structure(d, t)
assert converted == d
assert converted is not d
def test_structure_hook_func():
""" testing the hook_func method """
converter = Converter()
def can_handle(cls):
return cls.__name__.startswith("F")
def handle(obj, cls):
return "hi"
class Foo(object):
pass
class Bar(object):
pass
converter.register_structure_hook_func(can_handle, handle)
assert converter.structure(10, Foo) == "hi"
with raises(ValueError):
converter.structure(10, Bar)
def deserialize(*, data: str, structure: TStructure,
converter: cattr.Converter) -> TDeserializeReturn:
"""Translate API data into models."""
try:
data = json.loads(data)
except json.JSONDecodeError as ex:
raise DeserializeError(f"Bad json {ex}")
try:
response: TDeserializeReturn = converter.structure( # type: ignore
data, structure)
except (TypeError, AttributeError) as ex:
raise DeserializeError(f"Bad data {ex}")
return response
def test_stringifying_sets(set_and_type):
"""Test structuring generic sets and converting the contents to str."""
converter = Converter()
set_, input_set_type = set_and_type
if is_bare(input_set_type):
input_set_type = input_set_type[str]
else:
input_set_type.__args__ = (str, )
converted = converter.structure(set_, input_set_type)
assert len(converted) == len(set_)
for e in set_:
assert str(e) in converted
def test_stringifying_lists_of_opt(list_and_type):
"""Test structuring Optional primitive types into strings."""
converter = Converter()
l, t = list_and_type
l.append(None)
converted = converter.structure(l, List[Optional[str]])
for x, y in zip(l, converted):
if x is None:
assert x is y
else:
assert str(x) == y
def test_unmodified_generated_structuring(cl_and_vals):
converter = Converter()
cl, vals = cl_and_vals
fn = make_dict_structure_fn(cl, converter)
inst = cl(*vals)
unstructured = converter.unstructure(inst)
converter.register_structure_hook(cl, fn)
res = converter.structure(unstructured, cl)
assert inst == res
def test_structuring_hetero_tuples(list_of_vals_and_types):
"""Test structuring heterogenous tuples."""
converter = Converter()
types = tuple(e[1] for e in list_of_vals_and_types)
vals = [e[0] for e in list_of_vals_and_types]
t = Tuple[types]
converted = converter.structure(vals, t)
assert isinstance(converted, tuple)
for x, y in zip(vals, converted):
assert x == y
for x, y in zip(types, converted):
assert isinstance(y, x)
def test_stringifying_tuples(list_of_vals_and_types):
"""Stringify all elements of a heterogeneous tuple."""
converter = Converter()
vals = [e[0] for e in list_of_vals_and_types]
t = Tuple[(str, ) * len(list_of_vals_and_types)]
converted = converter.structure(vals, t)
assert isinstance(converted, tuple)
for x, y in zip(vals, converted):
assert str(x) == y
for x in converted:
# this should just be unicode, but in python2, '' is not unicode
assert isinstance(x, str)
def test_structuring_primitive_union_hook(ints):
"""Registering a union loading hook works."""
converter = Converter()
def structure_hook(val, cl):
"""Even ints are passed through, odd are stringified."""
return val if val % 2 == 0 else str(val)
converter.register_structure_hook(Union[str, int], structure_hook)
converted = converter.structure(ints, List[Union[str, int]])
for x, y in zip(ints, converted):
if x % 2 == 0:
assert x == y
else:
assert str(x) == y
def test_structure_union_edge_case():
converter = Converter()
@attr.s(auto_attribs=True)
class A:
a1: Any
a2: Optional[Any] = None
@attr.s(auto_attribs=True)
class B:
b1: Any
b2: Optional[Any] = None
assert converter.structure([{
"a1": "foo"
}, {
"b1": "bar"
}], List[Union[A, B]]) == [A("foo"), B("bar")]
def test_able_to_structure_generics(converter: Converter, t, t2, result):
res = converter.structure(asdict(result), TClass[t, t2])
assert res == result
def test_structuring_enums(data, enum):
"""Test structuring enums by their values."""
converter = Converter()
val = data.draw(sampled_from(list(enum)))
assert converter.structure(val.value, enum) == val
def test_structuring_primitives(primitive_and_type):
"""Test just structuring a primitive value."""
converter = Converter()
val, t = primitive_and_type
assert converter.structure(val, t) == val
assert converter.structure(val, Any) == val
