def handle_identity_conversion(conversion: ResolvedConversion,
tp: AnyType) -> ResolvedConversion:
if (is_identity(conversion) and conversion.source == conversion.target
and is_type_var(conversion.source)):
return ResolvedConversion(replace(conversion, source=tp, target=tp))
else:
return conversion
def subtyping_substitution(
supertype: AnyType, subtype: AnyType
) -> Tuple[Mapping[AnyType, AnyType], Mapping[AnyType, AnyType]]:
supertype, subtype = with_parameters(supertype), with_parameters(subtype)
supertype_to_subtype, subtype_to_supertype = {}, {}
super_origin = get_origin_or_type2(supertype)
for base in generic_mro(subtype):
base_origin = get_origin_or_type2(base)
if base_origin == super_origin or (base_origin in ITERABLE_TYPES
and super_origin in ITERABLE_TYPES):
for base_arg, super_arg in zip(get_args(base),
get_args(supertype)):
if is_type_var(super_arg):
supertype_to_subtype[super_arg] = base_arg
if is_type_var(base_arg):
subtype_to_supertype[base_arg] = super_arg
break
return supertype_to_subtype, subtype_to_supertype
def get_parameters(tp: AnyType) -> Iterable[TV]:
if hasattr(tp, "__parameters__"):
return tp.__parameters__
elif hasattr(tp, "__orig_bases__"):
return _collect_type_vars(tp.__orig_bases__)
elif is_type_var(tp):
return (tp, )
else:
return _type_vars
def instance_checker(tp: AnyType) -> Callable[[Any], bool]:
tp = get_origin_or_type2(tp)
if isinstance(tp, type):
return lambda obj: isinstance(obj, tp)
elif is_new_type(tp):
return instance_checker(tp.__supertype__)
elif is_type_var(tp):
return lambda obj: True
else:
raise TypeError(f"{tp} is not supported in union serialization")
def check_type(self, tp: AnyType):
if is_type_var(tp):
raise TypeError("TypeVar cannot have a type_name")
if has_type_vars(tp):
if get_args(tp):
raise TypeError("Generic alias cannot have a type_name")
elif isinstance(self.json_schema, str) or isinstance(self.graphql, str):
raise TypeError(
"Unspecialized generic type must used factory type_name"
)
def substitute_type_vars(tp: AnyType, substitution: Mapping[TV, AnyType]) -> AnyType:
if is_type_var(tp):
try:
return substitution[tp]
except KeyError:
return Union[tp.__constraints__] if tp.__constraints__ else Any
elif getattr(tp, "__parameters__", ()):
return tp[tuple(substitution.get(p, p) for p in tp.__parameters__)]
else:
return tp
def has_type_vars(tp: AnyType) -> bool:
return is_type_var(tp) or bool(getattr(tp, "__parameters__", ()))
