Mark stub-only private symbols as @type_check_only in third-party stubs (#14545)

stubs/WTForms/wtforms/fields/core.pyi

@@ -1,6 +1,6 @@
 from builtins import type as _type  # type is being shadowed in Field
 from collections.abc import Callable, Iterable, Sequence
-from typing import Any, Generic, Protocol, TypeVar, overload
+from typing import Any, Generic, Protocol, TypeVar, overload, type_check_only
 from typing_extensions import Self, TypeAlias
 
 from markupsafe import Markup
@@ -16,9 +16,11 @@ _FieldT_contra = TypeVar("_FieldT_contra", bound=Field, contravariant=True)
 # trust, that people won't use it to change the type of data in a field...
 _Filter: TypeAlias = Callable[[Any], Any]
 
+@type_check_only
 class _Validator(Protocol[_FormT_contra, _FieldT_contra]):
     def __call__(self, form: _FormT_contra, field: _FieldT_contra, /) -> object: ...
 
+@type_check_only
 class _Widget(Protocol[_FieldT_contra]):
     def __call__(self, field: _FieldT_contra, **kwargs: Any) -> Markup: ...
 

stubs/WTForms/wtforms/form.pyi

@@ -1,6 +1,6 @@
 from _typeshed import SupportsItems
 from collections.abc import Iterable, Iterator, Mapping, Sequence
-from typing import Any, ClassVar, Protocol, TypeVar, overload
+from typing import Any, ClassVar, Protocol, TypeVar, overload, type_check_only
 from typing_extensions import TypeAlias
 
 from wtforms.fields.core import Field, UnboundField
@@ -12,6 +12,7 @@ _FormErrors: TypeAlias = dict[str, Sequence[str] | _FormErrors]
 # _unbound_fields will always be a list on an instance, but on a
 # class it might be None, if it never has been instantiated, or
 # not instantianted after a new field had been added/removed
+@type_check_only
 class _UnboundFields(Protocol):
     @overload
     def __get__(self, obj: None, owner: type[object] | None = None, /) -> list[tuple[str, UnboundField[Any]]] | None: ...

stubs/WTForms/wtforms/i18n.pyi

@@ -1,9 +1,10 @@
 from collections.abc import Callable, Iterable
 from gettext import GNUTranslations
-from typing import Protocol, TypeVar, overload
+from typing import Protocol, TypeVar, overload, type_check_only
 
 _T = TypeVar("_T")
 
+@type_check_only
 class _SupportsUgettextAndUngettext(Protocol):
     def ugettext(self, string: str, /) -> str: ...
     def ungettext(self, singular: str, plural: str, n: int, /) -> str: ...

stubs/WTForms/wtforms/meta.pyi

@@ -1,6 +1,6 @@
 from _typeshed import SupportsItems
 from collections.abc import Collection, Iterator, MutableMapping
-from typing import Any, Literal, Protocol, TypeVar, overload
+from typing import Any, Literal, Protocol, TypeVar, overload, type_check_only
 from typing_extensions import TypeAlias
 
 from markupsafe import Markup
@@ -9,6 +9,7 @@ from wtforms.form import BaseForm
 
 _FieldT = TypeVar("_FieldT", bound=Field)
 
+@type_check_only
 class _SupportsGettextAndNgettext(Protocol):
     def gettext(self, string: str, /) -> str: ...
     def ngettext(self, singular: str, plural: str, n: int, /) -> str: ...
@@ -16,6 +17,7 @@ class _SupportsGettextAndNgettext(Protocol):
 # these are the methods WTForms depends on, the dict can either provide
 # a getlist or getall, if it only provides getall, it will wrapped, to
 # provide getlist instead
+@type_check_only
 class _MultiDictLikeBase(Protocol):
     def __iter__(self) -> Iterator[str]: ...
     def __len__(self) -> int: ...
@@ -24,9 +26,11 @@ class _MultiDictLikeBase(Protocol):
 # since how file uploads are represented in formdata is implementation-specific
 # we have to be generous in what we accept in the return of getlist/getall
 # we can make this generic if we ever want to be more specific
+@type_check_only
 class _MultiDictLikeWithGetlist(_MultiDictLikeBase, Protocol):
     def getlist(self, key: str, /) -> list[Any]: ...
 
+@type_check_only
 class _MultiDictLikeWithGetall(_MultiDictLikeBase, Protocol):
     def getall(self, key: str, /) -> list[Any]: ...