Update mypy and various typing improvements

requirements.txt

@@ -48,9 +48,9 @@ markupsafe==2.1.2
     # via jinja2
 mccabe==0.7.0
     # via flake8
-mypy==1.0.1
+mypy==1.10.0
     # via -r requirements.in
-mypy-extensions==0.4.3
+mypy-extensions==1.0.0
     # via
     #   black
     #   mypy
@@ -111,9 +111,9 @@ sphinxcontrib-serializinghtml==1.1.5
     # via sphinx
 tox==4.6.0
     # via -r requirements.in
-types-pycurl==7.45.2.0
+types-pycurl==7.45.3.20240421
     # via -r requirements.in
-typing-extensions==4.4.0
+typing-extensions==4.12.1
     # via mypy
 urllib3==1.26.18
     # via requests

tornado/concurrent.py

@@ -145,7 +145,10 @@ def wrapper(self: Any, *args: Any, **kwargs: Any) -> Future:
 _NO_RESULT = object()
 
 
-def chain_future(a: "Future[_T]", b: "Future[_T]") -> None:
+def chain_future(
+    a: Union["Future[_T]", "futures.Future[_T]"],
+    b: Union["Future[_T]", "futures.Future[_T]"],
+) -> None:
     """Chain two futures together so that when one completes, so does the other.
 
     The result (success or failure) of ``a`` will be copied to ``b``, unless

tornado/httputil.py

@@ -62,6 +62,12 @@
     from asyncio import Future  # noqa: F401
     import unittest  # noqa: F401
 
+    # This can be done unconditionally in the base class of HTTPHeaders
+    # after we drop support for Python 3.8.
+    StrMutableMapping = collections.abc.MutableMapping[str, str]
+else:
+    StrMutableMapping = collections.abc.MutableMapping
+
 # To be used with str.strip() and related methods.
 HTTP_WHITESPACE = " \t"
 
@@ -76,7 +82,7 @@ def _normalize_header(name: str) -> str:
     return "-".join([w.capitalize() for w in name.split("-")])
 
 
-class HTTPHeaders(collections.abc.MutableMapping):
+class HTTPHeaders(StrMutableMapping):
     """A dictionary that maintains ``Http-Header-Case`` for all keys.
 
     Supports multiple values per key via a pair of new methods,

tornado/platform/asyncio.py

@@ -49,6 +49,9 @@
     Union,
 )
 
+if typing.TYPE_CHECKING:
+    from typing_extensions import TypeVarTuple, Unpack
+
 
 class _HasFileno(Protocol):
     def fileno(self) -> int:
@@ -59,6 +62,8 @@ def fileno(self) -> int:
 
 _T = TypeVar("_T")
 
+if typing.TYPE_CHECKING:
+    _Ts = TypeVarTuple("_Ts")
 
 # Collection of selector thread event loops to shut down on exit.
 _selector_loops: Set["SelectorThread"] = set()
@@ -702,12 +707,18 @@ def close(self) -> None:
         self._real_loop.close()
 
     def add_reader(
-        self, fd: "_FileDescriptorLike", callback: Callable[..., None], *args: Any
+        self,
+        fd: "_FileDescriptorLike",
+        callback: Callable[..., None],
+        *args: "Unpack[_Ts]",
     ) -> None:
         return self._selector.add_reader(fd, callback, *args)
 
     def add_writer(
-        self, fd: "_FileDescriptorLike", callback: Callable[..., None], *args: Any
+        self,
+        fd: "_FileDescriptorLike",
+        callback: Callable[..., None],
+        *args: "Unpack[_Ts]",
     ) -> None:
         return self._selector.add_writer(fd, callback, *args)
 

tornado/test/concurrent_test.py

@@ -21,6 +21,7 @@
 
 from tornado.concurrent import (
     Future,
+    chain_future,
     run_on_executor,
     future_set_result_unless_cancelled,
 )
@@ -47,6 +48,31 @@ def test_future_set_result_unless_cancelled(self):
             self.assertEqual(fut.result(), 42)
 
 
+class ChainFutureTest(AsyncTestCase):
+    @gen_test
+    async def test_asyncio_futures(self):
+        fut: Future[int] = Future()
+        fut2: Future[int] = Future()
+        chain_future(fut, fut2)
+        fut.set_result(42)
+        result = await fut2
+        self.assertEqual(result, 42)
+
+    @gen_test
+    async def test_concurrent_futures(self):
+        # A three-step chain: two concurrent futures (showing that both arguments to chain_future
+        # can be concurrent futures), and then one from a concurrent future to an asyncio future so
+        # we can use it in await.
+        fut: futures.Future[int] = futures.Future()
+        fut2: futures.Future[int] = futures.Future()
+        fut3: Future[int] = Future()
+        chain_future(fut, fut2)
+        chain_future(fut2, fut3)
+        fut.set_result(42)
+        result = await fut3
+        self.assertEqual(result, 42)
+
+
 # The following series of classes demonstrate and test various styles
 # of use, with and without generators and futures.
 

tornado/web.py

@@ -192,7 +192,15 @@ class RequestHandler(object):
 
     """
 
-    SUPPORTED_METHODS = ("GET", "HEAD", "POST", "DELETE", "PATCH", "PUT", "OPTIONS")
+    SUPPORTED_METHODS: Tuple[str, ...] = (
+        "GET",
+        "HEAD",
+        "POST",
+        "DELETE",
+        "PATCH",
+        "PUT",
+        "OPTIONS",
+    )
 
     _template_loaders = {}  # type: Dict[str, template.BaseLoader]
     _template_loader_lock = threading.Lock()
@@ -1596,14 +1604,14 @@ def check_xsrf_cookie(self) -> None:
         # information please see
         # http://www.djangoproject.com/weblog/2011/feb/08/security/
         # http://weblog.rubyonrails.org/2011/2/8/csrf-protection-bypass-in-ruby-on-rails
-        token = (
+        input_token = (
             self.get_argument("_xsrf", None)
             or self.request.headers.get("X-Xsrftoken")
             or self.request.headers.get("X-Csrftoken")
         )
-        if not token:
+        if not input_token:
             raise HTTPError(403, "'_xsrf' argument missing from POST")
-        _, token, _ = self._decode_xsrf_token(token)
+        _, token, _ = self._decode_xsrf_token(input_token)
         _, expected_token, _ = self._get_raw_xsrf_token()
         if not token:
             raise HTTPError(403, "'_xsrf' argument has invalid format")
@@ -1886,7 +1894,7 @@ def render(*args, **kwargs) -> str:  # type: ignore
             if name not in self._active_modules:
                 self._active_modules[name] = module(self)
             rendered = self._active_modules[name].render(*args, **kwargs)
-            return rendered
+            return _unicode(rendered)
 
         return render
 
@@ -3323,7 +3331,7 @@ def __init__(self, handler: RequestHandler) -> None:
     def current_user(self) -> Any:
         return self.handler.current_user
 
-    def render(self, *args: Any, **kwargs: Any) -> str:
+    def render(self, *args: Any, **kwargs: Any) -> Union[str, bytes]:
         """Override in subclasses to return this module's output."""
         raise NotImplementedError()
 
@@ -3371,12 +3379,12 @@ def render_string(self, path: str, **kwargs: Any) -> bytes:
 
 
 class _linkify(UIModule):
-    def render(self, text: str, **kwargs: Any) -> str:  # type: ignore
+    def render(self, text: str, **kwargs: Any) -> str:
         return escape.linkify(text, **kwargs)
 
 
 class _xsrf_form_html(UIModule):
-    def render(self) -> str:  # type: ignore
+    def render(self) -> str:
         return self.handler.xsrf_form_html()
 
 
@@ -3402,7 +3410,7 @@ def __init__(self, handler: RequestHandler) -> None:
         self._resource_list = []  # type: List[Dict[str, Any]]
         self._resource_dict = {}  # type: Dict[str, Dict[str, Any]]
 
-    def render(self, path: str, **kwargs: Any) -> bytes:  # type: ignore
+    def render(self, path: str, **kwargs: Any) -> bytes:
         def set_resources(**kwargs) -> str:  # type: ignore
             if path not in self._resource_dict:
                 self._resource_list.append(kwargs)

tornado/websocket.py

@@ -1380,7 +1380,7 @@ def __init__(
             {
                 "Upgrade": "websocket",
                 "Connection": "Upgrade",
-                "Sec-WebSocket-Key": self.key,
+                "Sec-WebSocket-Key": to_unicode(self.key),
                 "Sec-WebSocket-Version": "13",
             }
         )