from __future__ import annotations
from inspect import isclass
from typing import TYPE_CHECKING, Any, Callable, Generic, TypeVar
from typing_extensions import get_type_hints
from polyfactory.exceptions import MissingDependencyException
from polyfactory.factories.base import BaseFactory
from polyfactory.field_meta import FieldMeta, Null
from polyfactory.utils.cache import copying_lru_cache
from polyfactory.value_generators.constrained_numbers import handle_constrained_int
from polyfactory.value_generators.primitives import create_random_bytes
if TYPE_CHECKING:
from typing_extensions import TypeGuard
try:
import msgspec
from msgspec.structs import fields
except ImportError as e:
msg = "msgspec is not installed"
raise MissingDependencyException(msg) from e
T = TypeVar("T", bound=msgspec.Struct)
[docs]class MsgspecFactory(Generic[T], BaseFactory[T]):
"""Base factory for msgspec Structs."""
__is_base_factory__ = True
[docs] @classmethod
@copying_lru_cache
def get_provider_map(cls) -> dict[Any, Callable[[], Any]]:
def get_msgpack_ext() -> msgspec.msgpack.Ext:
code = handle_constrained_int(cls.__random__, ge=-128, le=127)
data = create_random_bytes(cls.__random__)
return msgspec.msgpack.Ext(code, data)
msgspec_provider_map = {msgspec.UnsetType: lambda: msgspec.UNSET, msgspec.msgpack.Ext: get_msgpack_ext}
provider_map = super().get_provider_map()
provider_map.update(msgspec_provider_map)
return provider_map
[docs] @classmethod
def is_supported_type(cls, value: Any) -> TypeGuard[type[T]]:
return isclass(value) and hasattr(value, "__struct_fields__")
[docs] @classmethod
@copying_lru_cache
def get_model_fields(cls) -> list[FieldMeta]:
fields_meta: list[FieldMeta] = []
type_hints = get_type_hints(cls.__model__, include_extras=True)
for field in fields(cls.__model__):
annotation = type_hints[field.name]
if field.default is not msgspec.NODEFAULT:
default_value = field.default
elif field.default_factory is not msgspec.NODEFAULT:
default_value = field.default_factory()
else:
default_value = Null
fields_meta.append(
FieldMeta.from_type(
annotation=annotation,
name=field.name,
default=default_value,
random=cls.__random__,
),
)
return fields_meta
polyfactory