Add test to import all modules to check validity of stubs (#56)

* add import_all.test builder

* fix errors

* fix typechecking errors

* fix migrations typechecking

django-stubs/contrib/messages/storage/base.pyi

@@ -16,7 +16,7 @@ class Message:
     def level_tag(self) -> str: ...
 
 class BaseStorage:
-    request: Any = ...
+    request: HttpRequest = ...
     used: bool = ...
     added_new: bool = ...
     def __init__(self, request: HttpRequest, *args: Any, **kwargs: Any) -> None: ...

django-stubs/contrib/messages/storage/cookie.pyi

@@ -1,49 +1,20 @@
 import json
-from typing import Any, Dict, List, Optional, Union
+from typing import Any
 
-from django.contrib.messages.storage.base import BaseStorage, Message
+from django.contrib.messages.storage.base import BaseStorage
 
 class MessageEncoder(json.JSONEncoder):
     allow_nan: bool
     check_circular: bool
     ensure_ascii: bool
-    indent: None
-    item_separator: str
-    key_separator: str
     skipkeys: bool
     sort_keys: bool
     message_key: str = ...
-    def default(self, obj: Message) -> List[Union[int, str]]: ...
 
 class MessageDecoder(json.JSONDecoder):
-    def process_messages(
-        self,
-        obj: Union[
-            Dict[
-                str, Union[List[Union[Dict[str, List[Union[int, str]]], List[Union[int, str]]]], List[Union[int, str]]]
-            ],
-            List[Union[List[Union[int, str]], str]],
-            str,
-        ],
-    ) -> Union[
-        Dict[str, Union[List[Union[Dict[str, Message], Message]], Message]],
-        List[Union[Dict[str, Union[List[Union[Dict[str, Message], Message]], Message]], Message]],
-        List[Union[Message, str]],
-        Message,
-        str,
-    ]: ...
-    def decode(
-        self, s: str, **kwargs: Any
-    ) -> Union[
-        List[Union[Dict[str, Union[List[Union[Dict[str, Message], Message]], Message]], Message]],
-        List[Union[Message, str]],
-        Message,
-    ]: ...
+    def process_messages(self, obj: Any) -> Any: ...
 
 class CookieStorage(BaseStorage):
-    added_new: bool
-    request: WSGIRequest
-    used: bool
     cookie_name: str = ...
     max_cookie_size: int = ...
     not_finished: str = ...

django-stubs/contrib/messages/storage/fallback.pyi

@@ -1,11 +1,8 @@
-from typing import Any, Optional
+from typing import Any
 
 from django.contrib.messages.storage.base import BaseStorage
 
 class FallbackStorage(BaseStorage):
-    added_new: bool
-    request: WSGIRequest
-    used: bool
     storage_classes: Any = ...
     storages: Any = ...
     def __init__(self, *args: Any, **kwargs: Any) -> None: ...

django-stubs/contrib/messages/storage/session.pyi

@@ -1,15 +1,10 @@
-from typing import Any, List, Optional, Union
+from typing import Any, List, Optional, Sequence, Union
 
-from django.contrib.messages.storage.base import BaseStorage, Message
+from django.contrib.messages.storage.base import BaseStorage
 from django.http.request import HttpRequest
 
 class SessionStorage(BaseStorage):
-    added_new: bool
-    request: WSGIRequest
-    used: bool
     session_key: str = ...
     def __init__(self, request: HttpRequest, *args: Any, **kwargs: Any) -> None: ...
-    def serialize_messages(self, messages: Union[List[Message], List[str]]) -> str: ...
-    def deserialize_messages(
-        self, data: Optional[Union[List[Any], str]]
-    ) -> Optional[Union[List[Message], List[str]]]: ...
+    def serialize_messages(self, messages: Sequence[Any]) -> str: ...
+    def deserialize_messages(self, data: Optional[Union[List[Any], str]]) -> Optional[List[Any]]: ...