more fixes for django stubs, first attempt for a plugin

django-stubs/contrib/sessions/middleware.pyi

@@ -1,5 +1,6 @@
 from typing import Callable, Optional, Type
 
+from django.contrib.sessions.backends.base import SessionBase
 from django.core.handlers.wsgi import WSGIRequest
 from django.http.request import HttpRequest
 from django.http.response import HttpResponseBase
@@ -8,7 +9,7 @@ from django.utils.deprecation import MiddlewareMixin
 
 class SessionMiddleware(MiddlewareMixin):
     get_response: Callable[[WSGIRequest], HttpResponseBase] = ...
-    SessionStore: Type[SessionStore] = ...
+    SessionStore: Type[SessionBase] = ...
 
     def __init__(self, get_response: Optional[Callable] = ...) -> None: ...
 

django-stubs/core/cache/__init__.pyi

@@ -1,25 +1,32 @@
 from collections import OrderedDict
-from typing import Any, Callable, Dict, Optional, Union
+from typing import Any, Callable, Dict, Union
 
 from django.core.cache.backends.base import BaseCache as BaseCache
-from django.core.cache.backends.base import CacheKeyWarning as CacheKeyWarning
-from django.core.cache.backends.base import \
-    InvalidCacheBackendError as InvalidCacheBackendError
 
 DEFAULT_CACHE_ALIAS: str
 
+
 class CacheHandler:
     def __init__(self) -> None: ...
+
     def __getitem__(self, alias: str) -> BaseCache: ...
+
     def all(self): ...
 
+
 class DefaultCacheProxy:
     def __getattr__(
-        self, name: str
+            self, name: str
     ) -> Union[Callable, Dict[str, float], OrderedDict, int]: ...
+
     def __setattr__(self, name: str, value: Callable) -> None: ...
+
     def __delattr__(self, name: Any): ...
+
     def __contains__(self, key: str) -> bool: ...
+
     def __eq__(self, other: Any): ...
 
+
 cache: Any
+caches: CacheHandler

django-stubs/core/files/base.pyi

@@ -1,3 +1,4 @@
+from io import BufferedReader, StringIO
 from typing import Any, Iterator, Optional, Union
 
 from django.core.files.utils import FileProxyMixin
@@ -5,7 +6,7 @@ from django.core.files.utils import FileProxyMixin
 
 class File(FileProxyMixin):
     DEFAULT_CHUNK_SIZE: Any = ...
-    file: _io.BufferedReader = ...
+    file: BufferedReader = ...
     name: str = ...
     mode: str = ...
     def __init__(self, file: Any, name: Optional[str] = ...) -> None: ...
@@ -14,7 +15,7 @@ class File(FileProxyMixin):
     def size(self) -> int: ...
     def chunks(
         self, chunk_size: Optional[int] = ...
-    ) -> Iterator[Union[bytes, str]]: ...
+    ) -> Iterator[Union[bytes, bytearray]]: ...
     def multiple_chunks(self, chunk_size: Optional[Any] = ...): ...
     def __iter__(self) -> Iterator[Union[bytes, str]]: ...
     def __enter__(self) -> File: ...
@@ -23,7 +24,7 @@ class File(FileProxyMixin):
     def close(self) -> None: ...
 
 class ContentFile(File):
-    file: _io.StringIO
+    file: StringIO
     name: None
     size: Any = ...
     def __init__(

django-stubs/db/models/fields/related_descriptors.pyi

@@ -1,76 +1,110 @@
-from typing import Any, Callable, List, Optional, Tuple, Type, Union
+from typing import Any, Callable, List, Optional, Tuple, Type, Union, Generic, TypeVar
 
 from django.core.exceptions import ObjectDoesNotExist
 from django.db.models.base import Model
 from django.db.models.expressions import F
 from django.db.models.fields.mixins import FieldCacheMixin
-from django.db.models.fields.related import ForeignObject
+from django.db.models.fields.related import ForeignObject, RelatedField, OneToOneField
 from django.db.models.fields.reverse_related import ManyToManyRel, OneToOneRel
 from django.db.models.query import QuerySet
 
+_T = TypeVar('_T')
+
 
 class ForwardManyToOneDescriptor:
-    RelatedObjectDoesNotExist: Type[django.core.exceptions.ObjectDoesNotExist]
-    field: django.db.models.fields.related.ForeignObject = ...
+    RelatedObjectDoesNotExist: Type[ObjectDoesNotExist]
+    field: ForeignObject = ...
+
     def __init__(self, field_with_rel: ForeignObject) -> None: ...
-    def RelatedObjectDoesNotExist(self) -> Type[ObjectDoesNotExist]: ...
+
     def is_cached(self, instance: Model) -> bool: ...
+
     def get_queryset(self, **hints: Any) -> QuerySet: ...
+
     def get_prefetch_queryset(
-        self, instances: List[Model], queryset: Optional[QuerySet] = ...
+            self, instances: List[Model], queryset: Optional[QuerySet] = ...
     ) -> Tuple[QuerySet, Callable, Callable, bool, str, bool]: ...
+
     def get_object(self, instance: Model) -> Model: ...
+
     def __get__(
-        self, instance: Optional[Model], cls: Type[Model] = ...
+            self, instance: Optional[Model], cls: Type[Model] = ...
     ) -> Optional[Union[Model, ForwardManyToOneDescriptor]]: ...
+
     def __set__(
-        self, instance: Model, value: Optional[Union[Model, F]]
+            self, instance: Model, value: Optional[Union[Model, F]]
     ) -> None: ...
+
     def __reduce__(self) -> Tuple[Callable, Tuple[Type[Model], str]]: ...
 
+
 class ForwardOneToOneDescriptor(ForwardManyToOneDescriptor):
-    RelatedObjectDoesNotExist: Type[django.core.exceptions.ObjectDoesNotExist]
-    field: django.db.models.fields.related.OneToOneField
+    RelatedObjectDoesNotExist: Type[ObjectDoesNotExist]
+    field: OneToOneField
+
     def get_object(self, instance: Model) -> Model: ...
+
     def __set__(self, instance: Model, value: Optional[Model]) -> None: ...
 
+
 class ReverseOneToOneDescriptor:
-    RelatedObjectDoesNotExist: Type[django.core.exceptions.ObjectDoesNotExist]
-    related: django.db.models.fields.reverse_related.OneToOneRel = ...
+    RelatedObjectDoesNotExist: Type[ObjectDoesNotExist]
+    related: OneToOneRel = ...
+
     def __init__(self, related: OneToOneRel) -> None: ...
-    def RelatedObjectDoesNotExist(self) -> Type[ObjectDoesNotExist]: ...
+
     def is_cached(self, instance: Model) -> bool: ...
+
     def get_queryset(self, **hints: Any) -> QuerySet: ...
+
     def get_prefetch_queryset(
-        self, instances: List[Model], queryset: Optional[QuerySet] = ...
+            self, instances: List[Model], queryset: Optional[QuerySet] = ...
     ) -> Tuple[QuerySet, Callable, Callable, bool, str, bool]: ...
+
     def __get__(
-        self, instance: Optional[Model], cls: Type[Model] = ...
+            self, instance: Optional[Model], cls: Type[Model] = ...
     ) -> Union[Model, ReverseOneToOneDescriptor]: ...
+
     def __set__(self, instance: Model, value: Optional[Model]) -> None: ...
+
     def __reduce__(self) -> Tuple[Callable, Tuple[Type[Model], str]]: ...
 
+
 class ReverseManyToOneDescriptor:
-    rel: django.db.models.fields.mixins.FieldCacheMixin = ...
-    field: django.db.models.fields.mixins.FieldCacheMixin = ...
+    rel: FieldCacheMixin = ...
+    field: FieldCacheMixin = ...
+
     def __init__(self, rel: FieldCacheMixin) -> None: ...
+
     def related_manager_cls(self): ...
+
     def __get__(
-        self, instance: Optional[Model], cls: Type[Model] = ...
+            self, instance: Optional[Model], cls: Type[Model] = ...
     ) -> ReverseManyToOneDescriptor: ...
+
     def __set__(self, instance: Model, value: List[Model]) -> Any: ...
 
+
 def create_reverse_many_to_one_manager(superclass: Any, rel: Any): ...
 
+
 class ManyToManyDescriptor(ReverseManyToOneDescriptor):
-    field: django.db.models.fields.related.RelatedField
-    rel: django.db.models.fields.reverse_related.ManyToManyRel
+    field: RelatedField
+    rel: ManyToManyRel
     reverse: bool = ...
+
     def __init__(self, rel: ManyToManyRel, reverse: bool = ...) -> None: ...
+
     @property
     def through(self) -> Type[Model]: ...
+
     def related_manager_cls(self): ...
 
+
+class _ForwardManyToManyManager(Generic[_T]):
+    def all(self) -> QuerySet: ...
+
+
 def create_forward_many_to_many_manager(
-    superclass: Any, rel: Any, reverse: Any
-): ...
+        superclass: Any, rel: Any, reverse: Any
+) -> _ForwardManyToManyManager: ...

django-stubs/db/models/query.pyi

@@ -138,12 +138,7 @@ class QuerySet(Generic[_T]):
 
     def get(
             self, *args: Any, **kwargs: Any
-    ) -> Union[
-        Dict[str, Union[date, Decimal, float, str]],
-        Tuple[Union[Decimal, str]],
-        Model,
-        str,
-    ]: ...
+    ) -> _T: ...
 
     def create(self, **kwargs: Any) -> _T: ...
 

django-stubs/middleware/cache.pyi

@@ -1,5 +1,6 @@
 from typing import Any, Callable, Optional, Union
 
+from django.core.cache import BaseCache
 from django.http.request import HttpRequest
 from django.http.response import HttpResponse, HttpResponseBase
 from django.utils.deprecation import MiddlewareMixin
@@ -9,32 +10,39 @@ class UpdateCacheMiddleware(MiddlewareMixin):
     cache_timeout: float = ...
     key_prefix: str = ...
     cache_alias: str = ...
-    cache: django.core.cache.backends.base.BaseCache = ...
+    cache: BaseCache = ...
     get_response: Optional[Callable] = ...
+
     def __init__(self, get_response: Optional[Callable] = ...) -> None: ...
+
     def process_response(
-        self, request: HttpRequest, response: Union[HttpResponseBase, str]
+            self, request: HttpRequest, response: Union[HttpResponseBase, str]
     ) -> Union[HttpResponseBase, str]: ...
 
+
 class FetchFromCacheMiddleware(MiddlewareMixin):
     key_prefix: str = ...
     cache_alias: str = ...
-    cache: django.core.cache.backends.base.BaseCache = ...
+    cache: BaseCache = ...
     get_response: Optional[Callable] = ...
+
     def __init__(self, get_response: Optional[Callable] = ...) -> None: ...
+
     def process_request(
-        self, request: HttpRequest
+            self, request: HttpRequest
     ) -> Optional[HttpResponse]: ...
 
+
 class CacheMiddleware(UpdateCacheMiddleware, FetchFromCacheMiddleware):
     get_response: None = ...
     key_prefix: str = ...
     cache_alias: str = ...
     cache_timeout: float = ...
-    cache: django.core.cache.backends.locmem.LocMemCache = ...
+    cache: BaseCache = ...
+
     def __init__(
-        self,
-        get_response: None = ...,
-        cache_timeout: Optional[float] = ...,
-        **kwargs: Any
+            self,
+            get_response: None = ...,
+            cache_timeout: Optional[float] = ...,
+            **kwargs: Any
     ) -> None: ...

django-stubs/test/__init__.pyi

@@ -2,4 +2,8 @@ from .testcases import (
     TestCase as TestCase,
     TransactionTestCase as TransactionTestCase,
     SimpleTestCase as SimpleTestCase
+)
+
+from .utils import (
+    override_settings as override_settings
 )