feat: type more falcon modules (#2171)

* feat: Type app helpers module

* feat: Add typing to errors module

* feat: Add typings to forwarded module

* feat: Add typing to hooks

* feat: Add typing to falcon hooks

* feat: Add typing to http_error module

* feat: Extract RawHeaders and NormalizedHeaders to typing module

* feat: Extract status to typing module

* feat: Add typing to http_status module

* feat: Add typing to inspect module

* feat: Add typing to middleware module

* feat: Replace protocol with interface

* feat: Add typing to redirects

* feat: Type vendor mimeparse

* Changed RawHeaders to not include None

* Reformated imports

* Test that interface raises not implemented

* Type algorithm int values as float

* Changed allowed methods to Iterable

* Imported annotations in hooks

* Change argnames type to list of strings

* Changed Dict to mutable mapping

* Fixed formatting

* Remove unused imports

* Fix typing

* Replaced assert with cast

* Fix blue

* Type resource as object

* Fix style

* Revert "Type algorithm int values as float"

This reverts commit ca1df71.

* Revert "feat: Type vendor mimeparse"

This reverts commit 11ca7ca.

* Ignore vendore package

* Use async package instead of importing AsyncRequest and AsyncResponse and aliasing them

* Solve circular imports while typing

* Fix style

* Changed inspect obj type to Any

* Import annotations where missing

* Replace Union with | where future annotations imported

* Revert "Replace Union with | where future annotations imported"

This reverts commit fd8b3be.

* Improve imports to avoid them inside functions

* Fix typo

* Rename Kwargs to HTTPErrorKeywordArgs

* Import whole package insted of specific types

* Fix style

* Replace Serializer and MediaHandler with protocol

* Add assertion reason message

* Fix import issue

* Fix import order

* Fix coverage issues

* Add ResponderOrResource and Action types

* style: run ruff

* typing: apply review feedmack

* typing: avoid protocols for handlers

* typing: improve type alias name

* fix: restore support to python 3.8 and 3.7

---------

Co-authored-by: Federico Caselli <cfederico87@gmail.com>

Author: copalco

falcon/app.py

@@ -674,7 +674,7 @@ def add_static_route(
         self._static_routes.insert(0, (sr, sr, False))
         self._update_sink_and_static_routes()
 
-    def add_sink(self, sink: Callable, prefix: SinkPrefix = r'/'):
+    def add_sink(self, sink: Callable, prefix: SinkPrefix = r'/') -> None:
         """Register a sink method for the App.
 
         If no route matches a request, but the path in the requested URI

falcon/app_helpers.py

@@ -14,6 +14,8 @@
 
 """Utilities for the App class."""
 
+from __future__ import annotations
+
 from inspect import iscoroutinefunction
 from typing import IO, Iterable, List, Tuple
 
@@ -202,7 +204,7 @@ def prepare_middleware_ws(middleware: Iterable) -> Tuple[list, list]:
     return request_mw, resource_mw
 
 
-def default_serialize_error(req: Request, resp: Response, exception: HTTPError):
+def default_serialize_error(req: Request, resp: Response, exception: HTTPError) -> None:
     """Serialize the given instance of HTTPError.
 
     This function determines which of the supported media types, if
@@ -281,22 +283,22 @@ class CloseableStreamIterator:
         block_size (int): Number of bytes to read per iteration.
     """
 
-    def __init__(self, stream: IO, block_size: int):
+    def __init__(self, stream: IO, block_size: int) -> None:
         self._stream = stream
         self._block_size = block_size
 
-    def __iter__(self):
+    def __iter__(self) -> CloseableStreamIterator:
         return self
 
-    def __next__(self):
+    def __next__(self) -> bytes:
         data = self._stream.read(self._block_size)
 
         if data == b'':
             raise StopIteration
         else:
             return data
 
-    def close(self):
+    def close(self) -> None:
         try:
             self._stream.close()
         except (AttributeError, TypeError):

falcon/asgi_spec.py

@@ -14,6 +14,8 @@
 
 """Constants, etc. defined by the ASGI specification."""
 
+from __future__ import annotations
+
 
 class EventType:
     """Standard ASGI event type strings."""