feat(typing): finalize annotations (#2338)

* typing: type jsonschema

* typing: add missing future annotation; add lint rule to check for it

* refactor: rename HeaderList to HeaderArg

* typing: type testing helpers

* typing: type testing client

* typing: properly type return value of test client simulate* methods.

fixes: #2207

* fix: assert is valid only after getting the data

* chore: ignore fa errors in tutorial

---------

Co-authored-by: Vytautas Liuolia <[email protected]>

falcon/app.py

@@ -14,6 +14,8 @@
 
 """Falcon App class."""
 
+from __future__ import annotations
+
 from functools import wraps
 from inspect import iscoroutinefunction
 import pathlib

falcon/asgi/app.py

@@ -14,6 +14,8 @@
 
 """ASGI application class."""
 
+from __future__ import annotations
+
 import asyncio
 from inspect import isasyncgenfunction
 from inspect import iscoroutinefunction

falcon/asgi/ws.py

@@ -17,7 +17,7 @@
 from falcon.constants import WebSocketPayloadType
 from falcon.typing import AsgiReceive
 from falcon.typing import AsgiSend
-from falcon.typing import HeaderList
+from falcon.typing import HeaderArg
 from falcon.util import misc
 
 __all__ = ('WebSocket',)
@@ -144,7 +144,7 @@ def supports_accept_headers(self) -> bool:
     async def accept(
         self,
         subprotocol: Optional[str] = None,
-        headers: Optional[HeaderList] = None,
+        headers: Optional[HeaderArg] = None,
     ) -> None:
         """Accept the incoming WebSocket connection.
 
@@ -166,7 +166,7 @@ async def accept(
                 client may choose to abandon the connection in this case,
                 if it does not receive an explicit protocol selection.
 
-            headers (HeaderList): An iterable of ``(name: str, value: str)``
+            headers (HeaderArg): An iterable of ``(name: str, value: str)``
                 two-item iterables, representing a collection of HTTP headers to
                 include in the handshake response. Both *name* and *value* must
                 be of type ``str`` and contain only US-ASCII characters.