from __future__ import annotations
from dataclasses import MISSING, fields, is_dataclass
from typing import Any, Generic
from typing_extensions import TypeGuard, get_type_hints
from polyfactory.factories.base import BaseFactory, T
from polyfactory.field_meta import FieldMeta, Null
[docs]class DataclassFactory(Generic[T], BaseFactory[T]):
"""Dataclass base factory"""
__is_base_factory__ = True
[docs] @classmethod
def is_supported_type(cls, value: Any) -> TypeGuard[type[T]]:
"""Determine whether the given value is supported by the factory.
:param value: An arbitrary value.
:returns: A typeguard
"""
return bool(is_dataclass(value))
[docs] @classmethod
def get_model_fields(cls) -> list["FieldMeta"]:
"""Retrieve a list of fields from the factory's model.
:returns: A list of field MetaData instances.
"""
fields_meta: list["FieldMeta"] = []
model_type_hints = get_type_hints(cls.__model__, include_extras=True)
for field in fields(cls.__model__): # type: ignore[arg-type]
if not field.init:
continue
if field.default_factory and field.default_factory is not MISSING:
default_value = field.default_factory()
elif field.default is not MISSING:
default_value = field.default
else:
default_value = Null
fields_meta.append(
FieldMeta.from_type(
annotation=model_type_hints[field.name],
name=field.name,
default=default_value,
random=cls.__random__,
),
)
return fields_meta
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