Use TypeAlias where possible for type aliases (#7630)

stdlib/asyncio/base_events.pyi

@@ -9,7 +9,7 @@ from asyncio.transports import BaseTransport, ReadTransport, SubprocessTransport
 from collections.abc import Iterable
 from socket import AddressFamily, SocketKind, _Address, _RetAddress, socket
 from typing import IO, Any, Awaitable, Callable, Coroutine, Generator, Sequence, TypeVar, overload
-from typing_extensions import Literal
+from typing_extensions import Literal, TypeAlias
 
 if sys.version_info >= (3, 7):
     from contextvars import Context
@@ -23,10 +23,10 @@ else:
 
 _T = TypeVar("_T")
 _ProtocolT = TypeVar("_ProtocolT", bound=BaseProtocol)
-_Context = dict[str, Any]
-_ExceptionHandler = Callable[[AbstractEventLoop, _Context], Any]
-_ProtocolFactory = Callable[[], BaseProtocol]
-_SSLContext = bool | None | ssl.SSLContext
+_Context: TypeAlias = dict[str, Any]
+_ExceptionHandler: TypeAlias = Callable[[AbstractEventLoop, _Context], Any]
+_ProtocolFactory: TypeAlias = Callable[[], BaseProtocol]
+_SSLContext: TypeAlias = bool | None | ssl.SSLContext
 
 class Server(AbstractServer):
     if sys.version_info >= (3, 7):

stdlib/asyncio/base_subprocess.pyi

@@ -1,10 +1,11 @@
 import subprocess
 from collections import deque
 from typing import IO, Any, Callable, Sequence
+from typing_extensions import TypeAlias
 
 from . import events, futures, protocols, transports
 
-_File = int | IO[Any] | None
+_File: TypeAlias = int | IO[Any] | None
 
 class BaseSubprocessTransport(transports.SubprocessTransport):
 

stdlib/asyncio/events.pyi

@@ -4,7 +4,7 @@ from _typeshed import FileDescriptorLike, Self
 from abc import ABCMeta, abstractmethod
 from socket import AddressFamily, SocketKind, _Address, _RetAddress, socket
 from typing import IO, Any, Awaitable, Callable, Coroutine, Generator, Sequence, TypeVar, overload
-from typing_extensions import Literal
+from typing_extensions import Literal, TypeAlias
 
 from .base_events import Server
 from .futures import Future
@@ -75,10 +75,10 @@ else:
 
 _T = TypeVar("_T")
 _ProtocolT = TypeVar("_ProtocolT", bound=BaseProtocol)
-_Context = dict[str, Any]
-_ExceptionHandler = Callable[[AbstractEventLoop, _Context], Any]
-_ProtocolFactory = Callable[[], BaseProtocol]
-_SSLContext = bool | None | ssl.SSLContext
+_Context: TypeAlias = dict[str, Any]
+_ExceptionHandler: TypeAlias = Callable[[AbstractEventLoop, _Context], Any]
+_ProtocolFactory: TypeAlias = Callable[[], BaseProtocol]
+_SSLContext: TypeAlias = bool | None | ssl.SSLContext
 
 class Handle:
     _cancelled: bool

stdlib/asyncio/format_helpers.pyi

@@ -2,11 +2,12 @@ import functools
 import traceback
 from types import FrameType, FunctionType
 from typing import Any, Iterable, overload
+from typing_extensions import TypeAlias
 
 class _HasWrapper:
     __wrapper__: _HasWrapper | FunctionType
 
-_FuncType = FunctionType | _HasWrapper | functools.partial[Any] | functools.partialmethod[Any]
+_FuncType: TypeAlias = FunctionType | _HasWrapper | functools.partial[Any] | functools.partialmethod[Any]
 
 @overload
 def _get_function_source(func: _FuncType) -> tuple[str, int]: ...

stdlib/asyncio/streams.pyi

@@ -1,6 +1,7 @@
 import sys
 from _typeshed import Self, StrPath
 from typing import Any, AsyncIterator, Awaitable, Callable, Iterable, Sequence
+from typing_extensions import TypeAlias
 
 from . import events, protocols, transports
 from .base_events import Server
@@ -64,7 +65,7 @@ else:
             "start_unix_server",
         ]
 
-_ClientConnectedCallback = Callable[[StreamReader, StreamWriter], Awaitable[None] | None]
+_ClientConnectedCallback: TypeAlias = Callable[[StreamReader, StreamWriter], Awaitable[None] | None]
 
 if sys.version_info < (3, 8):
     class IncompleteReadError(EOFError):

stdlib/asyncio/subprocess.pyi

@@ -3,7 +3,7 @@ import sys
 from _typeshed import StrOrBytesPath
 from asyncio import events, protocols, streams, transports
 from typing import IO, Any, Callable
-from typing_extensions import Literal
+from typing_extensions import Literal, TypeAlias
 
 if sys.version_info >= (3, 7):
     __all__ = ("create_subprocess_exec", "create_subprocess_shell")
@@ -11,9 +11,9 @@ else:
     __all__ = ["create_subprocess_exec", "create_subprocess_shell"]
 
 if sys.version_info >= (3, 8):
-    _ExecArg = StrOrBytesPath
+    _ExecArg: TypeAlias = StrOrBytesPath
 else:
-    _ExecArg = str | bytes
+    _ExecArg: TypeAlias = str | bytes
 
 PIPE: int
 STDOUT: int

stdlib/asyncio/tasks.pyi

@@ -3,7 +3,7 @@ import sys
 from collections.abc import Awaitable, Generator, Iterable, Iterator
 from types import FrameType
 from typing import Any, Coroutine, Generic, TextIO, TypeVar, overload
-from typing_extensions import Literal
+from typing_extensions import Literal, TypeAlias
 
 from .events import AbstractEventLoop
 from .futures import Future
@@ -56,8 +56,8 @@ _T3 = TypeVar("_T3")
 _T4 = TypeVar("_T4")
 _T5 = TypeVar("_T5")
 _FT = TypeVar("_FT", bound=Future[Any])
-_FutureT = Future[_T] | Generator[Any, None, _T] | Awaitable[_T]
-_TaskYieldType = Future[object] | None
+_FutureT: TypeAlias = Future[_T] | Generator[Any, None, _T] | Awaitable[_T]
+_TaskYieldType: TypeAlias = Future[object] | None
 
 FIRST_COMPLETED = concurrent.futures.FIRST_COMPLETED
 FIRST_EXCEPTION = concurrent.futures.FIRST_EXCEPTION

stdlib/asyncio/trsock.pyi

@@ -3,12 +3,13 @@ import sys
 from builtins import type as Type  # alias to avoid name clashes with property named "type"
 from types import TracebackType
 from typing import Any, BinaryIO, Iterable, NoReturn, overload
+from typing_extensions import TypeAlias
 
 # These are based in socket, maybe move them out into _typeshed.pyi or such
-_Address = tuple[Any, ...] | str
-_RetAddress = Any
-_WriteBuffer = bytearray | memoryview
-_CMSG = tuple[int, int, bytes]
+_Address: TypeAlias = tuple[Any, ...] | str
+_RetAddress: TypeAlias = Any
+_WriteBuffer: TypeAlias = bytearray | memoryview
+_CMSG: TypeAlias = tuple[int, int, bytes]
 
 class TransportSocket:
     def __init__(self, sock: socket.socket) -> None: ...