asyncio.events: various fixes (#3931)

- connect_accepted_socket isn't a member of AbstractEventLoop, only
BaseEventLoop
- fix types of arguments with defaults. some of these functions could
have their signatures improved with overloads to reduce false negatives
- correctly mark a positional-only argument
- remove abstractmethod from methods that don't have abstractmethod and
go unimplemented in practice

stdlib/3/asyncio/events.pyi

@@ -192,18 +192,13 @@ class AbstractEventLoop(metaclass=ABCMeta):
                                 family: int = ..., flags: int = ..., sock: socket = ..., backlog: int = ...,
                                 ssl: _SSLContext = ..., reuse_address: Optional[bool] = ..., reuse_port: Optional[bool] = ...,
                                 ssl_handshake_timeout: Optional[float] = ..., start_serving: bool = ...) -> AbstractServer: ...
-        @abstractmethod
-        async def create_unix_connection(self, protocol_factory: _ProtocolFactory, path: str, *, ssl: _SSLContext = ...,
-                                         sock: Optional[socket] = ..., server_hostname: str = ...,
+        async def create_unix_connection(self, protocol_factory: _ProtocolFactory, path: Optional[str] = ..., *, ssl: _SSLContext = ...,
+                                         sock: Optional[socket] = ..., server_hostname: Optional[str] = ...,
                                          ssl_handshake_timeout: Optional[float] = ...) -> _TransProtPair: ...
-        @abstractmethod
-        async def create_unix_server(self, protocol_factory: _ProtocolFactory, path: str, *, sock: Optional[socket] = ...,
+        async def create_unix_server(self, protocol_factory: _ProtocolFactory, path: Optional[str] = ..., *, sock: Optional[socket] = ...,
                                      backlog: int = ..., ssl: _SSLContext = ..., ssl_handshake_timeout: Optional[float] = ...,
                                      start_serving: bool = ...) -> AbstractServer: ...
         @abstractmethod
-        async def connect_accepted_socket(self, protocol_factory: _ProtocolFactory, sock: socket, *, ssl: _SSLContext = ...,
-                                          ssl_handshake_timeout: Optional[float] = ...) -> _TransProtPair: ...
-        @abstractmethod
         async def sendfile(self, transport: BaseTransport, file: IO[bytes], offset: int = ..., count: Optional[int] = ..., *,
                            fallback: bool = ...) -> int: ...
         @abstractmethod
@@ -225,15 +220,11 @@ class AbstractEventLoop(metaclass=ABCMeta):
                                 sock: socket, backlog: int = ..., ssl: _SSLContext = ...,
                                 reuse_address: Optional[bool] = ...,
                                 reuse_port: Optional[bool] = ...) -> AbstractServer: ...
-        @abstractmethod
         async def create_unix_connection(self, protocol_factory: _ProtocolFactory, path: str, *,
                                          ssl: _SSLContext = ..., sock: Optional[socket] = ...,
-                                         server_hostname: str = ...) -> _TransProtPair: ...
-        @abstractmethod
+                                         server_hostname: Optional[str] = ...) -> _TransProtPair: ...
         async def create_unix_server(self, protocol_factory: _ProtocolFactory, path: str, *,
                                      sock: Optional[socket] = ..., backlog: int = ..., ssl: _SSLContext = ...) -> AbstractServer: ...
-        @abstractmethod
-        async def connect_accepted_socket(self, protocol_factory: _ProtocolFactory, sock: socket, *, ssl: _SSLContext = ...) -> _TransProtPair: ...
     @abstractmethod
     async def create_datagram_endpoint(self, protocol_factory: _ProtocolFactory,
                                        local_addr: Optional[Tuple[str, int]] = ..., remote_addr: Optional[Tuple[str, int]] = ..., *,
@@ -332,7 +323,7 @@ def new_event_loop() -> AbstractEventLoop: ...
 def get_child_watcher() -> AbstractChildWatcher: ...
 def set_child_watcher(watcher: AbstractChildWatcher) -> None: ...
 
-def _set_running_loop(loop: Optional[AbstractEventLoop]) -> None: ...
+def _set_running_loop(__loop: Optional[AbstractEventLoop]) -> None: ...
 def _get_running_loop() -> AbstractEventLoop: ...
 
 if sys.version_info >= (3, 7):

stdlib/3/asyncio/proactor_events.pyi

@@ -46,35 +46,4 @@ class _ProactorSocketTransport(_ProactorReadPipeTransport, _ProactorBaseWritePip
     def write_eof(self) -> None: ...
 
 class BaseProactorEventLoop(base_events.BaseEventLoop):
-
     def __init__(self, proactor: Any) -> None: ...
-    # The methods below don't actually exist directly, ProactorEventLoops do not implement them. However, they are
-    # needed to satisfy mypy
-    if sys.version_info >= (3, 7):
-        async def create_unix_connection(
-            self,
-            protocol_factory: events._ProtocolFactory,
-            path: _Path,
-            *,
-            ssl: events._SSLContext = ...,
-            sock: Optional[socket] = ...,
-            server_hostname: str = ...,
-            ssl_handshake_timeout: Optional[float] = ...,
-        ) -> events._TransProtPair: ...
-        async def create_unix_server(
-            self,
-            protocol_factory: events._ProtocolFactory,
-            path: _Path,
-            *,
-            sock: Optional[socket] = ...,
-            backlog: int = ...,
-            ssl: events._SSLContext = ...,
-            ssl_handshake_timeout: Optional[float] = ...,
-            start_serving: bool = ...,
-        ) -> events.AbstractServer: ...
-    else:
-        async def create_unix_connection(self, protocol_factory: events._ProtocolFactory, path: str, *,
-                                         ssl: events._SSLContext = ..., sock: Optional[socket] = ...,
-                                         server_hostname: str = ...) -> events._TransProtPair: ...
-        async def create_unix_server(self, protocol_factory: events._ProtocolFactory, path: str, *,
-                                     sock: Optional[socket] = ..., backlog: int = ..., ssl: events._SSLContext = ...) -> events.AbstractServer: ...

stdlib/3/asyncio/selector_events.pyi

@@ -1,7 +1,7 @@
 import selectors
 import sys
 from socket import socket
-from typing import Optional, Union
+from typing import Any, Optional, Union
 
 from . import base_events, events
 
@@ -12,33 +12,4 @@ else:
     _Path = str
 
 class BaseSelectorEventLoop(base_events.BaseEventLoop):
-
     def __init__(self, selector: Optional[selectors.BaseSelector] = ...) -> None: ...
-    if sys.version_info >= (3, 7):
-        async def create_unix_connection(
-            self,
-            protocol_factory: events._ProtocolFactory,
-            path: _Path,
-            *,
-            ssl: events._SSLContext = ...,
-            sock: Optional[socket] = ...,
-            server_hostname: str = ...,
-            ssl_handshake_timeout: Optional[float] = ...,
-        ) -> events._TransProtPair: ...
-        async def create_unix_server(
-            self,
-            protocol_factory: events._ProtocolFactory,
-            path: _Path,
-            *,
-            sock: Optional[socket] = ...,
-            backlog: int = ...,
-            ssl: events._SSLContext = ...,
-            ssl_handshake_timeout: Optional[float] = ...,
-            start_serving: bool = ...,
-        ) -> events.AbstractServer: ...
-    else:
-        async def create_unix_connection(self, protocol_factory: events._ProtocolFactory, path: str, *,
-                                         ssl: events._SSLContext = ..., sock: Optional[socket] = ...,
-                                         server_hostname: str = ...) -> events._TransProtPair: ...
-        async def create_unix_server(self, protocol_factory: events._ProtocolFactory, path: str, *,
-                                     sock: Optional[socket] = ..., backlog: int = ..., ssl: events._SSLContext = ...) -> events.AbstractServer: ...