Add some replication tests (#7278)

Specifically some tests for the typing stream, which means we test streams that fetch missing updates via HTTP (rather than via the DB).

We also shuffle things around a bit so that we create two separate `HomeServer` objects, rather than trying to insert a slaved store into places.

Note: `test_typing.py` is heavily inspired by `test_receipts.py`

tests/replication/tcp/streams/test_typing.py

@@ -0,0 +1,80 @@
+# -*- 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 synapse.handlers.typing import RoomMember
+from synapse.replication.http import streams
+from synapse.replication.tcp.streams import TypingStream
+
+from tests.replication.tcp.streams._base import BaseStreamTestCase
+
+USER_ID = "@feeling:blue"
+
+
+class TypingStreamTestCase(BaseStreamTestCase):
+    servlets = [
+        streams.register_servlets,
+    ]
+
+    def test_typing(self):
+        typing = self.hs.get_typing_handler()
+
+        room_id = "!bar:blue"
+
+        self.reconnect()
+
+        # make the client subscribe to the receipts stream
+        self.test_handler.streams.add("typing")
+
+        typing._push_update(member=RoomMember(room_id, USER_ID), typing=True)
+
+        self.reactor.advance(0)
+
+        # We should now see an attempt to connect to the master
+        request = self.handle_http_replication_attempt()
+        self.assert_request_is_get_repl_stream_updates(request, "typing")
+
+        self.test_handler.on_rdata.assert_called_once()
+        stream_name, token, rdata_rows = self.test_handler.on_rdata.call_args[0]
+        self.assertEqual(stream_name, "typing")
+        self.assertEqual(1, len(rdata_rows))
+        row = rdata_rows[0]  # type: TypingStream.TypingStreamRow
+        self.assertEqual(room_id, row.room_id)
+        self.assertEqual([USER_ID], row.user_ids)
+
+        # Now let's disconnect and insert some data.
+        self.disconnect()
+
+        self.test_handler.on_rdata.reset_mock()
+
+        typing._push_update(member=RoomMember(room_id, USER_ID), typing=False)
+
+        self.test_handler.on_rdata.assert_not_called()
+
+        self.reconnect()
+        self.pump(0.1)
+
+        # We should now see an attempt to connect to the master
+        request = self.handle_http_replication_attempt()
+        self.assert_request_is_get_repl_stream_updates(request, "typing")
+
+        # The from token should be the token from the last RDATA we got.
+        self.assertEqual(int(request.args[b"from_token"][0]), token)
+
+        self.test_handler.on_rdata.assert_called_once()
+        stream_name, token, rdata_rows = self.test_handler.on_rdata.call_args[0]
+        self.assertEqual(stream_name, "typing")
+        self.assertEqual(1, len(rdata_rows))
+        row = rdata_rows[0]  # type: TypingStream.TypingStreamRow
+        self.assertEqual(room_id, row.room_id)
+        self.assertEqual([], row.user_ids)