Add typechecking for 'file_storage', 'files' test folders (#101)

* add typechecking for 'file_storage', 'files' test folders

* fix File class annotations

django-stubs/core/files/base.pyi

@@ -1,12 +1,13 @@
 from io import StringIO
-from typing import Any, Iterator, Optional, Union
+from typing import Any, Iterator, Optional, Union, IO, Type
+from types import TracebackType
 
 from django.core.files.utils import FileProxyMixin
 
-class File(FileProxyMixin):
+class File(FileProxyMixin, IO[Any]):
     DEFAULT_CHUNK_SIZE: Any = ...
     file: StringIO = ...
-    name: Optional[str] = ...
+    name: str = ...
     mode: str = ...
     def __init__(self, file: Any, name: Optional[str] = ...) -> None: ...
     def __bool__(self) -> bool: ...
@@ -15,8 +16,11 @@ class File(FileProxyMixin):
     def chunks(self, chunk_size: Optional[int] = ...) -> Iterator[Union[bytes, bytearray]]: ...
     def multiple_chunks(self, chunk_size: Optional[Any] = ...): ...
     def __iter__(self) -> Iterator[Union[bytes, str]]: ...
+    def __next__(self) -> Union[bytes, str]: ...
     def __enter__(self) -> File: ...
-    def __exit__(self, exc_type: None, exc_value: None, tb: None) -> None: ...
+    def __exit__(
+        self, exc_type: Optional[Type[BaseException]], exc_value: Optional[BaseException], tb: Optional[TracebackType]
+    ) -> bool: ...
     def open(self, mode: Optional[str] = ...) -> File: ...
     def close(self) -> None: ...
 

django-stubs/core/files/images.pyi

@@ -1,5 +1,4 @@
-from io import BytesIO
-from typing import Any, Union
+from typing import Any, IO, Union
 
 from django.core.files import File
 
@@ -11,4 +10,4 @@ class ImageFile(File):
     @property
     def height(self) -> int: ...
 
-def get_image_dimensions(file_or_path: Union[BytesIO, str], close: bool = ...) -> Any: ...
+def get_image_dimensions(file_or_path: Union[str, IO[bytes]], close: bool = ...) -> Any: ...

django-stubs/core/files/storage.pyi

@@ -1,5 +1,5 @@
 from datetime import datetime
-from typing import Any, IO, List, Optional, Tuple
+from typing import Any, List, Optional, Tuple, IO
 
 from django.core.files.base import File
 from django.utils.functional import LazyObject