Rework TestReplicationDataHandler

This wasn't very easy to work with: the mock wrapping was largely superfluous,
and it's useful to be able to inspect the received rows, and clear out the
received list.

tests/replication/tcp/streams/_base.py

@@ -12,10 +12,9 @@
 # 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.
-import logging
-from typing import Optional
 
-from mock import Mock
+import logging
+from typing import Any, Dict, List, Optional, Tuple
 
 import attr
 
@@ -25,6 +24,7 @@ from twisted.web.http import HTTPChannel
 
 from synapse.app.generic_worker import GenericWorkerServer
 from synapse.http.site import SynapseRequest
+from synapse.replication.slave.storage._base import BaseSlavedStore
 from synapse.replication.tcp.client import ReplicationDataHandler
 from synapse.replication.tcp.handler import ReplicationCommandHandler
 from synapse.replication.tcp.protocol import ClientReplicationStreamProtocol
@@ -65,9 +65,7 @@ class BaseStreamTestCase(unittest.HomeserverTestCase):
         # databases objects are the same.
         self.worker_hs.get_datastore().db = hs.get_datastore().db
 
-        self.test_handler = Mock(
-            wraps=TestReplicationDataHandler(self.worker_hs.get_datastore())
-        )
+        self.test_handler = self._build_replication_data_handler()
         self.worker_hs.replication_data_handler = self.test_handler
 
         repl_handler = ReplicationCommandHandler(self.worker_hs)
@@ -78,6 +76,9 @@ class BaseStreamTestCase(unittest.HomeserverTestCase):
         self._client_transport = None
         self._server_transport = None
 
+    def _build_replication_data_handler(self):
+        return TestReplicationDataHandler(self.worker_hs.get_datastore())
+
     def reconnect(self):
         if self._client_transport:
             self.client.close()
@@ -174,22 +175,28 @@ class BaseStreamTestCase(unittest.HomeserverTestCase):
 class TestReplicationDataHandler(ReplicationDataHandler):
     """Drop-in for ReplicationDataHandler which just collects RDATA rows"""
 
-    def __init__(self, hs):
-        super().__init__(hs)
-        self.streams = set()
-        self._received_rdata_rows = []
+    def __init__(self, store: BaseSlavedStore):
+        super().__init__(store)
+
+        # streams to subscribe to: map from stream id to position
+        self.stream_positions = {}  # type: Dict[str, int]
+
+        # list of received (stream_name, token, row) tuples
+        self.received_rdata_rows = []  # type: List[Tuple[str, int, Any]]
 
     def get_streams_to_replicate(self):
-        positions = {s: 0 for s in self.streams}
-        for stream, token, _ in self._received_rdata_rows:
-            if stream in self.streams:
-                positions[stream] = max(token, positions.get(stream, 0))
-        return positions
+        return self.stream_positions
 
     async def on_rdata(self, stream_name, token, rows):
         await super().on_rdata(stream_name, token, rows)
         for r in rows:
-            self._received_rdata_rows.append((stream_name, token, r))
+            self.received_rdata_rows.append((stream_name, token, r))
+
+        if (
+            stream_name in self.stream_positions
+            and token > self.stream_positions[stream_name]
+        ):
+            self.stream_positions[stream_name] = token
 
 
 @attr.s()
@@ -221,7 +228,7 @@ class _PushHTTPChannel(HTTPChannel):
         super().__init__()
         self.reactor = reactor
 
-        self._pull_to_push_producer = None
+        self._pull_to_push_producer = None  # type: Optional[_PullToPushProducer]
 
     def registerProducer(self, producer, streaming):
         # Convert pull producers to push producer.

tests/replication/tcp/streams/test_receipts.py

@@ -12,6 +12,11 @@
 # 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.
+
+# type: ignore
+
+from mock import Mock
+
 from synapse.replication.tcp.streams._base import ReceiptsStream
 
 from tests.replication.tcp.streams._base import BaseStreamTestCase
@@ -20,11 +25,14 @@ USER_ID = "@feeling:blue"
 
 
 class ReceiptsStreamTestCase(BaseStreamTestCase):
+    def _build_replication_data_handler(self):
+        return Mock(wraps=super()._build_replication_data_handler())
+
     def test_receipt(self):
         self.reconnect()
 
         # make the client subscribe to the receipts stream
-        self.test_handler.streams.add("receipts")
+        self.test_handler.stream_positions.update({"receipts": 0})
 
         # tell the master to send a new receipt
         self.get_success(

tests/replication/tcp/streams/test_typing.py

@@ -12,6 +12,8 @@
 # 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 unittest.mock import Mock
+
 from synapse.handlers.typing import RoomMember
 from synapse.replication.http import streams
 from synapse.replication.tcp.streams import TypingStream
@@ -26,6 +28,9 @@ class TypingStreamTestCase(BaseStreamTestCase):
         streams.register_servlets,
     ]
 
+    def _build_replication_data_handler(self):
+        return Mock(wraps=super()._build_replication_data_handler())
+
     def test_typing(self):
         typing = self.hs.get_typing_handler()
 
@@ -33,8 +38,8 @@ class TypingStreamTestCase(BaseStreamTestCase):
 
         self.reconnect()
 
-        # make the client subscribe to the receipts stream
-        self.test_handler.streams.add("typing")
+        # make the client subscribe to the typing stream
+        self.test_handler.stream_positions.update({"typing": 0})
 
         typing._push_update(member=RoomMember(room_id, USER_ID), typing=True)
 
@@ -75,6 +80,6 @@ class TypingStreamTestCase(BaseStreamTestCase):
         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
+        row = rdata_rows[0]
         self.assertEqual(room_id, row.room_id)
         self.assertEqual([], row.user_ids)

tox.ini

@@ -204,6 +204,7 @@ commands = mypy \
             synapse/storage/database.py \
             synapse/streams \
             synapse/util/caches/stream_change_cache.py \
+            tests/replication/tcp/streams \
             tests/test_utils \
             tests/util/test_stream_change_cache.py