feat(proxy): proxy for aiohttp,base sessions (#284)

* feat(proxy): proxy for aiohttp,base sessions

Add support for proxies in aiohttp session with aiohttp_socks library,
edit BaseSession class to support proxies for other sessions in future.

* fix(annotation): missing underscore before "private" typevar

* chore: remove redundant of proxy_url schema for socks version

* test: add missing test

Add missing test, remove BaseSession.cfg and switch to
implementing class' "private" traits, add aiohttp_socks in dependency list as
optional and extra.

* feat(session):

Implement asyncio session for requests [wip]

* feat(proxy chain): Chained proxy support in aiohttp session

Add ChainProxyConnector support, !pin pydantic to "1.4", add
documentation on aiohttp connector.

* style(mypy): apply linter changes

* tests(mock): remove await for magic mock

* fix dangling dependency

* refactor(generic):

get rid of generic behaviour for base session

tests/test_api/test_client/test_session/test_aiohttp_session.py

@@ -1,6 +1,7 @@
 from typing import AsyncContextManager, AsyncGenerator
 
 import aiohttp
+import aiohttp_socks
 import pytest
 from aresponses import ResponsesMockServer
 
@@ -29,6 +30,59 @@ class TestAiohttpSession:
         assert session._session is not None
         assert isinstance(aiohttp_session, aiohttp.ClientSession)
 
+    @pytest.mark.asyncio
+    async def test_create_proxy_session(self):
+        session = AiohttpSession(
+            proxy=("socks5://proxy.url/", aiohttp.BasicAuth("login", "password", "encoding"))
+        )
+
+        assert session._connector_type == aiohttp_socks.ProxyConnector
+
+        assert isinstance(session._connector_init, dict)
+        assert session._connector_init["proxy_type"] is aiohttp_socks.ProxyType.SOCKS5
+
+        aiohttp_session = await session.create_session()
+        assert isinstance(aiohttp_session.connector, aiohttp_socks.ProxyConnector)
+
+    @pytest.mark.asyncio
+    async def test_create_proxy_session_proxy_url(self):
+        session = AiohttpSession(proxy="socks4://proxy.url/")
+
+        assert isinstance(session.proxy, str)
+
+        assert isinstance(session._connector_init, dict)
+        assert session._connector_init["proxy_type"] is aiohttp_socks.ProxyType.SOCKS4
+
+        aiohttp_session = await session.create_session()
+        assert isinstance(aiohttp_session.connector, aiohttp_socks.ProxyConnector)
+
+    @pytest.mark.asyncio
+    async def test_create_proxy_session_chained_proxies(self):
+        session = AiohttpSession(
+            proxy=[
+                "socks4://proxy.url/",
+                "socks5://proxy.url/",
+                "http://user:password@127.0.0.1:3128",
+            ]
+        )
+
+        assert isinstance(session.proxy, list)
+
+        assert isinstance(session._connector_init, dict)
+        assert isinstance(session._connector_init["proxy_infos"], list)
+        assert isinstance(session._connector_init["proxy_infos"][0], aiohttp_socks.ProxyInfo)
+
+        assert (
+            session._connector_init["proxy_infos"][0].proxy_type is aiohttp_socks.ProxyType.SOCKS4
+        )
+        assert (
+            session._connector_init["proxy_infos"][1].proxy_type is aiohttp_socks.ProxyType.SOCKS5
+        )
+        assert session._connector_init["proxy_infos"][2].proxy_type is aiohttp_socks.ProxyType.HTTP
+
+        aiohttp_session = await session.create_session()
+        assert isinstance(aiohttp_session.connector, aiohttp_socks.ChainProxyConnector)
+
     @pytest.mark.asyncio
     async def test_close_session(self):
         session = AiohttpSession()