test: Bring the MockSHSSocket testing class in line with the secret-handshake library

tests/test_packet_stream.py

@@ -25,7 +25,7 @@
 from asyncio import Event, ensure_future, gather
 from asyncio.events import AbstractEventLoop
 import json
-from typing import Any, AsyncIterator, Awaitable, Callable, Generator, List, Optional
+from typing import AsyncIterator, Awaitable, Callable, Generator, List, Optional
 
 import pytest
 from pytest_mock import MockerFixture
@@ -66,24 +66,24 @@ MSG_BODY_2 = (
 class MockSHSSocket(SHSDuplexStream):
     """A mocked SHS socket"""
 
-    def __init__(self, *args: Any, **kwargs: Any):  # pylint: disable=unused-argument
+    def __init__(self) -> None:
         super().__init__()
 
         self.input: List[bytes] = []
         self.output: List[bytes] = []
         self.is_connected: bool = False
-        self._on_connect: List[Callable[[], Awaitable[None]]] = []
+        self._on_connect: List[Callable[[SHSDuplexStream], Awaitable[None]]] = []
 
-    def on_connect(self, cb: Callable[[], Awaitable[None]]) -> None:
+    def on_connect(self, cb: Callable[[SHSDuplexStream], Awaitable[None]]) -> None:
         """Set the on_connect callback"""
 
         self._on_connect.append(cb)
 
-    async def read(self) -> Optional[bytes]:
+    async def read(self) -> bytes:
         """Read data from the socket"""
 
         if not self.input:
-            return None
+            raise StopAsyncIteration()
 
         return self.input.pop(0)
 
@@ -125,7 +125,7 @@ class MockSHSServer(MockSHSSocket):
         self.is_connected = True
 
         for cb in self._on_connect:
-            ensure_future(cb())
+            ensure_future(cb(self))
 
 
 @pytest.fixture
@@ -148,7 +148,7 @@ async def test_on_connect(ps_server: MockSHSServer) -> None:  # pylint: disable=
 
     called = Event()
 
-    async def _on_connect() -> None:
+    async def _on_connect(_: SHSDuplexStream) -> None:
         called.set()
 
     ps_server.on_connect(_on_connect)