WsPool refactoring, TCP fallback backoff, removed direct connections outside of a pool

tests/test_tcp_fallback.py

@@ -0,0 +1,109 @@
+import asyncio
+import time
+import unittest
+from unittest.mock import AsyncMock, Mock, patch
+
+from proxy import bridge
+
+
+class TcpFallbackTest(unittest.IsolatedAsyncioTestCase):
+    async def asyncSetUp(self):
+        bridge.reset_tcp_backoff()
+        self.addCleanup(bridge.reset_tcp_backoff)
+        self.key = ('192.0.2.1', 443)
+        self.remote = Mock(drain=AsyncMock(), wait_closed=AsyncMock())
+
+    async def fallback(self, dst='192.0.2.1', port=443):
+        return await bridge._tcp_fallback(
+            Mock(), Mock(), dst, port, b'init', 'test', Mock())
+
+    async def test_failure_backoff_doubles_caps_and_skips_new_connections(self):
+        with patch.object(bridge.asyncio, 'open_connection',
+                          AsyncMock(side_effect=asyncio.TimeoutError())) as connect:
+            for delay in (30, 60, 120, 240, 480, 960, 1920, 3600, 3600):
+                bridge._tcp_retry_after[self.key] = 0
+                start = time.monotonic()
+                self.assertFalse(await self.fallback())
+                remaining = bridge._tcp_retry_after[self.key] - start
+                self.assertGreaterEqual(remaining, delay - .001)
+                self.assertLess(remaining, delay + 1)
+                count = connect.await_count
+                self.assertFalse(await self.fallback())
+                self.assertEqual(connect.await_count, count)
+        self.assertFalse(bridge._tcp_connecting)
+
+    async def test_other_ips_and_ports_are_not_blocked(self):
+        bridge._tcp_retry_after[self.key] = time.monotonic() + 60
+        with patch.object(bridge.asyncio, 'open_connection', AsyncMock(
+                return_value=(Mock(), self.remote))) as connect, \
+                patch.object(bridge, '_bridge_tcp_reencrypt', AsyncMock()):
+            self.assertTrue(await self.fallback('192.0.2.2'))
+            self.assertTrue(await self.fallback(port=80))
+        self.assertEqual(connect.await_count, 2)
+
+    async def test_success_clears_backoff_and_allows_following_sessions(self):
+        bridge._tcp_failures[self.key] = 5
+        bridge._tcp_retry_after[self.key] = 0
+        with patch.object(bridge.asyncio, 'open_connection', AsyncMock(
+                return_value=(Mock(), self.remote))) as connect, \
+                patch.object(bridge, '_bridge_tcp_reencrypt', AsyncMock()):
+            self.assertTrue(await self.fallback())
+            self.assertNotIn(self.key, bridge._tcp_failures)
+            self.assertNotIn(self.key, bridge._tcp_retry_after)
+            self.assertTrue(await self.fallback())
+        self.assertEqual(connect.await_count, 2)
+
+    async def test_concurrent_requests_only_start_one_connection_attempt(self):
+        started = asyncio.Event()
+        release = asyncio.Event()
+
+        async def connect(*args):
+            started.set()
+            await release.wait()
+            raise ConnectionRefusedError()
+
+        with patch.object(bridge.asyncio, 'open_connection', side_effect=connect) as dial:
+            first = asyncio.create_task(self.fallback())
+            try:
+                await asyncio.wait_for(started.wait(), 1)
+                results = await asyncio.gather(*(self.fallback() for _ in range(8)))
+                self.assertEqual(results, [False] * 8)
+                self.assertEqual(dial.await_count, 1)
+                release.set()
+                self.assertFalse(await first)
+            finally:
+                first.cancel()
+                await asyncio.gather(first, return_exceptions=True)
+
+    async def test_init_failure_closes_socket_and_enters_backoff(self):
+        self.remote.drain.side_effect = ConnectionResetError()
+        with patch.object(bridge.asyncio, 'open_connection', AsyncMock(
+                return_value=(Mock(), self.remote))), \
+                patch.object(bridge, '_bridge_tcp_reencrypt', AsyncMock()) as forward:
+            self.assertFalse(await self.fallback())
+        self.remote.close.assert_called_once()
+        forward.assert_not_awaited()
+        self.assertIn(self.key, bridge._tcp_retry_after)
+
+    async def test_cancellation_releases_attempt_without_marking_ip_blocked(self):
+        started = asyncio.Event()
+
+        async def drain():
+            started.set()
+            await asyncio.Future()
+
+        self.remote.drain.side_effect = drain
+        with patch.object(bridge.asyncio, 'open_connection', AsyncMock(
+                return_value=(Mock(), self.remote))):
+            task = asyncio.create_task(self.fallback())
+            await asyncio.wait_for(started.wait(), 1)
+            task.cancel()
+            with self.assertRaises(asyncio.CancelledError):
+                await task
+        self.remote.close.assert_called_once()
+        self.assertFalse(bridge._tcp_connecting)
+        self.assertFalse(bridge._tcp_failures)
+
+
+if __name__ == '__main__':
+    unittest.main()