Add test

tests/replication/tcp/test_remote_server_up.py

@@ -0,0 +1,62 @@
+# -*- coding: utf-8 -*-
+# Copyright 2020 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from typing import Tuple
+
+from twisted.internet.interfaces import IProtocol
+from twisted.test.proto_helpers import StringTransport
+
+from synapse.replication.tcp.resource import ReplicationStreamProtocolFactory
+
+from tests.unittest import HomeserverTestCase
+
+
+class RemoteServerUpTestCase(HomeserverTestCase):
+    def prepare(self, reactor, clock, hs):
+        self.factory = ReplicationStreamProtocolFactory(hs)
+
+    def _make_client(self) -> Tuple[IProtocol, StringTransport]:
+        """Create a new direct TCP replication connection
+        """
+
+        proto = self.factory.buildProtocol(("127.0.0.1", 0))
+        transport = StringTransport()
+        proto.makeConnection(transport)
+
+        # We can safely ignore the commands received during connection.
+        self.pump()
+        transport.clear()
+
+        return proto, transport
+
+    def test_relay(self):
+        """Test that Synapse will relay REMOTE_SERVER_UP commands to all
+        other connections, but not the one that sent it.
+        """
+
+        proto1, transport1 = self._make_client()
+
+        # We shouldn't receive an echo.
+        proto1.dataReceived(b"REMOTE_SERVER_UP example.com\n")
+        self.pump()
+        self.assertEqual(transport1.value(), b"")
+
+        # But we should see an echo if we connect another client
+        proto2, transport2 = self._make_client()
+        proto1.dataReceived(b"REMOTE_SERVER_UP example.com\n")
+
+        self.pump()
+        self.assertEqual(transport1.value(), b"")
+        self.assertEqual(transport2.value(), b"REMOTE_SERVER_UP example.com\n")