aiohttp reuses SSLContext instances created at import-time (#259)

* `aiohttp` reuses SSLContext instances created at import-time.

mocket/__init__.py

@@ -1,6 +1,13 @@
 from .async_mocket import async_mocketize
-from .mocket import Mocket, MocketEntry, Mocketizer, mocketize
+from .mocket import FakeSSLContext, Mocket, MocketEntry, Mocketizer, mocketize
 
-__all__ = ("async_mocketize", "mocketize", "Mocket", "MocketEntry", "Mocketizer")
+__all__ = (
+    "async_mocketize",
+    "mocketize",
+    "Mocket",
+    "MocketEntry",
+    "Mocketizer",
+    "FakeSSLContext",
+)
 
 __version__ = "3.13.1"

mocket/plugins/aiohttp_connector.py

@@ -0,0 +1,18 @@
+import contextlib
+
+from mocket import FakeSSLContext
+
+with contextlib.suppress(ModuleNotFoundError):
+    from aiohttp import ClientRequest
+    from aiohttp.connector import TCPConnector
+
+    class MocketTCPConnector(TCPConnector):
+        """
+        `aiohttp` reuses SSLContext instances created at import-time,
+        making it more difficult for Mocket to do its job.
+        This is an attempt to make things smoother, at the cost of
+        slightly patching the `ClientSession` while testing.
+        """
+
+        def _get_ssl_context(self, req: ClientRequest) -> FakeSSLContext:
+            return FakeSSLContext()

tests/test_asyncio.py

@@ -4,10 +4,12 @@
 import socket
 import tempfile
 
+import aiohttp
 import pytest
 
 from mocket import Mocketizer, async_mocketize
 from mocket.mockhttp import Entry
+from mocket.plugins.aiohttp_connector import MocketTCPConnector
 
 
 def test_asyncio_record_replay(event_loop):
@@ -45,7 +47,10 @@ async def test_asyncio_connection():
 @pytest.mark.asyncio
 @async_mocketize
 async def test_aiohttp():
-    import aiohttp
+    """
+    The alternative to using the custom `connector` would be importing
+    `aiohttp` when Mocket is already in control (inside the decorated test).
+    """
 
     url = "https://bar.foo/"
     data = {"message": "Hello"}
@@ -58,7 +63,7 @@ async def test_aiohttp():
     )
 
     async with aiohttp.ClientSession(
-        timeout=aiohttp.ClientTimeout(total=3)
+        timeout=aiohttp.ClientTimeout(total=3), connector=MocketTCPConnector()
     ) as session, session.get(url) as response:
         response = await response.json()
         assert response == data