Style: add type hints (#2217)

* style(routes): add_route argument, return typing

* style(listeners): typing

* style(views): typing as_view

* style(routes): change type hint

* style(listeners): change type hint

* style(routes): change type hint

* add some more types

* Change as_view typing

* Add some cleaner type annotations

Co-authored-by: Adam Hopkins <adam@amhopkins.com>

sanic/mixins/listeners.py

@@ -1,8 +1,9 @@
 from enum import Enum, auto
 from functools import partial
-from typing import Any, Callable, Coroutine, List, Optional, Union
+from typing import List, Optional, Union
 
 from sanic.models.futures import FutureListener
+from sanic.models.handler_types import ListenerType
 
 
 class ListenerEvent(str, Enum):
@@ -26,9 +27,7 @@ class ListenerMixin:
 
     def listener(
         self,
-        listener_or_event: Union[
-            Callable[..., Coroutine[Any, Any, None]], str
-        ],
+        listener_or_event: Union[ListenerType, str],
         event_or_none: Optional[str] = None,
         apply: bool = True,
     ):
@@ -63,20 +62,20 @@ class ListenerMixin:
         else:
             return partial(register_listener, event=listener_or_event)
 
-    def main_process_start(self, listener):
+    def main_process_start(self, listener: ListenerType) -> ListenerType:
         return self.listener(listener, "main_process_start")
 
-    def main_process_stop(self, listener):
+    def main_process_stop(self, listener: ListenerType) -> ListenerType:
         return self.listener(listener, "main_process_stop")
 
-    def before_server_start(self, listener):
+    def before_server_start(self, listener: ListenerType) -> ListenerType:
         return self.listener(listener, "before_server_start")
 
-    def after_server_start(self, listener):
+    def after_server_start(self, listener: ListenerType) -> ListenerType:
         return self.listener(listener, "after_server_start")
 
-    def before_server_stop(self, listener):
+    def before_server_stop(self, listener: ListenerType) -> ListenerType:
         return self.listener(listener, "before_server_stop")
 
-    def after_server_stop(self, listener):
+    def after_server_stop(self, listener: ListenerType) -> ListenerType:
         return self.listener(listener, "after_server_stop")

sanic/mixins/routes.py

@@ -5,7 +5,7 @@ from os import path
 from pathlib import PurePath
 from re import sub
 from time import gmtime, strftime
-from typing import Iterable, List, Optional, Set, Union
+from typing import Callable, Iterable, List, Optional, Set, Tuple, Union
 from urllib.parse import unquote
 
 from sanic_routing.route import Route  # type: ignore
@@ -21,10 +21,16 @@ from sanic.exceptions import (
 from sanic.handlers import ContentRangeHandler
 from sanic.log import error_logger
 from sanic.models.futures import FutureRoute, FutureStatic
+from sanic.models.handler_types import RouteHandler
 from sanic.response import HTTPResponse, file, file_stream
 from sanic.views import CompositionView
 
 
+RouteWrapper = Callable[
+    [RouteHandler], Union[RouteHandler, Tuple[Route, RouteHandler]]
+]
+
+
 class RouteMixin:
     name: str
 
@@ -55,7 +61,7 @@ class RouteMixin:
         unquote: bool = False,
         static: bool = False,
         version_prefix: str = "/v",
-    ):
+    ) -> RouteWrapper:
         """
         Decorate a function to be registered as a route
 
@@ -168,7 +174,7 @@ class RouteMixin:
 
     def add_route(
         self,
-        handler,
+        handler: RouteHandler,
         uri: str,
         methods: Iterable[str] = frozenset({"GET"}),
         host: Optional[str] = None,
@@ -177,7 +183,7 @@ class RouteMixin:
         name: Optional[str] = None,
         stream: bool = False,
         version_prefix: str = "/v",
-    ):
+    ) -> RouteHandler:
         """A helper method to register class instance or
         functions as a handler to the application url
         routes.
@@ -200,7 +206,8 @@ class RouteMixin:
             methods = set()
 
             for method in HTTP_METHODS:
-                _handler = getattr(handler.view_class, method.lower(), None)
+                view_class = getattr(handler, "view_class")
+                _handler = getattr(view_class, method.lower(), None)
                 if _handler:
                     methods.add(method)
                     if hasattr(_handler, "is_stream"):
@@ -239,7 +246,7 @@ class RouteMixin:
         name: Optional[str] = None,
         ignore_body: bool = True,
         version_prefix: str = "/v",
-    ):
+    ) -> RouteWrapper:
         """
         Add an API URL under the **GET** *HTTP* method
 
@@ -273,7 +280,7 @@ class RouteMixin:
         version: Optional[int] = None,
         name: Optional[str] = None,
         version_prefix: str = "/v",
-    ):
+    ) -> RouteWrapper:
         """
         Add an API URL under the **POST** *HTTP* method
 
@@ -307,7 +314,7 @@ class RouteMixin:
         version: Optional[int] = None,
         name: Optional[str] = None,
         version_prefix: str = "/v",
-    ):
+    ) -> RouteWrapper:
         """
         Add an API URL under the **PUT** *HTTP* method
 
@@ -341,7 +348,7 @@ class RouteMixin:
         name: Optional[str] = None,
         ignore_body: bool = True,
         version_prefix: str = "/v",
-    ):
+    ) -> RouteWrapper:
         """
         Add an API URL under the **HEAD** *HTTP* method
 
@@ -383,7 +390,7 @@ class RouteMixin:
         name: Optional[str] = None,
         ignore_body: bool = True,
         version_prefix: str = "/v",
-    ):
+    ) -> RouteWrapper:
         """
         Add an API URL under the **OPTIONS** *HTTP* method
 
@@ -425,7 +432,7 @@ class RouteMixin:
         version: Optional[int] = None,
         name: Optional[str] = None,
         version_prefix: str = "/v",
-    ):
+    ) -> RouteWrapper:
         """
         Add an API URL under the **PATCH** *HTTP* method
 
@@ -469,7 +476,7 @@ class RouteMixin:
         name: Optional[str] = None,
         ignore_body: bool = True,
         version_prefix: str = "/v",
-    ):
+    ) -> RouteWrapper:
         """
         Add an API URL under the **DELETE** *HTTP* method
 
@@ -847,7 +854,7 @@ class RouteMixin:
             )
         )
 
-        route, _ = self.route(
+        route, _ = self.route(  # type: ignore
             uri=uri,
             methods=["GET", "HEAD"],
             name=name,

sanic/models/handler_types.py

@@ -21,5 +21,5 @@ MiddlewareType = Union[RequestMiddlewareType, ResponseMiddlewareType]
 ListenerType = Callable[
     [Sanic, AbstractEventLoop], Optional[Coroutine[Any, Any, None]]
 ]
-RouteHandler = Callable[..., Coroutine[Any, Any, HTTPResponse]]
+RouteHandler = Callable[..., Coroutine[Any, Any, Optional[HTTPResponse]]]
 SignalHandler = Callable[..., Coroutine[Any, Any, None]]

sanic/views.py

@@ -13,6 +13,7 @@ from warnings import warn
 
 from sanic.constants import HTTP_METHODS
 from sanic.exceptions import InvalidUsage
+from sanic.models.handler_types import RouteHandler
 
 
 if TYPE_CHECKING:
@@ -86,7 +87,7 @@ class HTTPMethodView:
         return handler(request, *args, **kwargs)
 
     @classmethod
-    def as_view(cls, *class_args, **class_kwargs):
+    def as_view(cls, *class_args: Any, **class_kwargs: Any) -> RouteHandler:
         """Return view function for use with the routing system, that
         dispatches request to appropriate handler method.
         """
@@ -100,7 +101,7 @@ class HTTPMethodView:
             for decorator in cls.decorators:
                 view = decorator(view)
 
-        view.view_class = cls
+        view.view_class = cls  # type: ignore
         view.__doc__ = cls.__doc__
         view.__module__ = cls.__module__
         view.__name__ = cls.__name__