from __future__ import annotations
from typing import Any, Callable, Generic, TypedDict, TypeVar, cast
from typing_extensions import ParamSpec
T = TypeVar("T")
P = ParamSpec("P")
[docs]
class WrappedCallable(TypedDict):
"""A ref storing a callable. This class is a utility meant to prevent binding of methods."""
value: Callable
[docs]
class Require:
"""A factory field that marks an attribute as a required build-time kwarg."""
[docs]
class Ignore:
"""A factory field that marks an attribute as ignored."""
[docs]
class Use(Generic[P, T]):
"""Factory field used to wrap a callable.
The callable will be invoked whenever building the given factory attribute.
"""
__slots__ = ("args", "fn", "kwargs")
[docs]
def __init__(self, fn: Callable[P, T], *args: P.args, **kwargs: P.kwargs) -> None:
"""Wrap a callable.
:param fn: A callable to wrap.
:param args: Any args to pass to the callable.
:param kwargs: Any kwargs to pass to the callable.
"""
self.fn: WrappedCallable = {"value": fn}
self.kwargs = kwargs
self.args = args
[docs]
def to_value(self) -> T:
"""Invoke the callable.
:returns: The output of the callable.
"""
return cast("T", self.fn["value"](*self.args, **self.kwargs))
[docs]
class PostGenerated:
"""Factory field that allows generating values after other fields are generated by the factory."""
__slots__ = ("args", "fn", "kwargs")
[docs]
def __init__(self, fn: Callable, *args: Any, **kwargs: Any) -> None:
"""Designate field as post-generated.
:param fn: A callable.
:param args: Args for the callable.
:param kwargs: Kwargs for the callable.
"""
self.fn: WrappedCallable = {"value": fn}
self.kwargs = kwargs
self.args = args
[docs]
def to_value(self, name: str, values: dict[str, Any]) -> Any:
"""Invoke the post-generation callback passing to it the build results.
:param name: Field name.
:param values: Generated values.
:returns: An arbitrary value.
"""
return self.fn["value"](name, values, *self.args, **self.kwargs)
polyfactory