Fix bug where read-receipts lost their timestamps (#4927)

Make sure that they are sent correctly over the replication stream.

Fixes: #4898

tests/replication/tcp/streams/_base.py

@@ -0,0 +1,74 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 New Vector Ltd
+#
+# 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 synapse.replication.tcp.commands import ReplicateCommand
+from synapse.replication.tcp.protocol import ClientReplicationStreamProtocol
+from synapse.replication.tcp.resource import ReplicationStreamProtocolFactory
+
+from tests import unittest
+from tests.server import FakeTransport
+
+
+class BaseStreamTestCase(unittest.HomeserverTestCase):
+    """Base class for tests of the replication streams"""
+    def prepare(self, reactor, clock, hs):
+        # build a replication server
+        server_factory = ReplicationStreamProtocolFactory(self.hs)
+        self.streamer = server_factory.streamer
+        server = server_factory.buildProtocol(None)
+
+        # build a replication client, with a dummy handler
+        self.test_handler = TestReplicationClientHandler()
+        self.client = ClientReplicationStreamProtocol(
+            "client", "test", clock, self.test_handler
+        )
+
+        # wire them together
+        self.client.makeConnection(FakeTransport(server, reactor))
+        server.makeConnection(FakeTransport(self.client, reactor))
+
+    def replicate(self):
+        """Tell the master side of replication that something has happened, and then
+        wait for the replication to occur.
+        """
+        self.streamer.on_notifier_poke()
+        self.pump(0.1)
+
+    def replicate_stream(self, stream, token="NOW"):
+        """Make the client end a REPLICATE command to set up a subscription to a stream"""
+        self.client.send_command(ReplicateCommand(stream, token))
+
+
+class TestReplicationClientHandler(object):
+    """Drop-in for ReplicationClientHandler which just collects RDATA rows"""
+    def __init__(self):
+        self.received_rdata_rows = []
+
+    def get_streams_to_replicate(self):
+        return {}
+
+    def get_currently_syncing_users(self):
+        return []
+
+    def update_connection(self, connection):
+        pass
+
+    def finished_connecting(self):
+        pass
+
+    def on_rdata(self, stream_name, token, rows):
+        for r in rows:
+            self.received_rdata_rows.append(
+                (stream_name, token, r)
+            )