Add tests

I decided to spin up another test class for this as the existing one is
1. quite old and 2. was mocking away too much of the infrastructure to
my liking. I've named the new class alluding to ephemeral messages, and
while we already have some ephemeral tests in AppServiceHandlerTestCase,
ideally I'd like to migrate those over.

There's two new tests here. One for testing that to-device messages for
a local user are received by any application services that have
registered interest in that user - and that those that haven't won't
receive those messages.

The next test is similar, but tests with a whole bunch of to-device
messages. Rather than registering tons of devices - which would make for
a very slow unit test - I decided to just directly insert most of the
to-device messages into the database, then send a final one via the API.
Sending via the API is necessary to kick off the appservice scheduler.
It also allows us to test old messages being sent out correctly.

tests/handlers/test_appservice.py

@@ -1,4 +1,4 @@
-# Copyright 2015, 2016 OpenMarket Ltd
+# Copyright 2015-2021 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.
@@ -12,18 +12,24 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Dict, Iterable, List, Optional, Tuple
 from unittest.mock import Mock
 
 from twisted.internet import defer
 
+import synapse.rest.admin
+import synapse.storage
+from synapse.appservice import ApplicationService
 from synapse.handlers.appservice import ApplicationServicesHandler
-from synapse.types import RoomStreamToken
+from synapse.rest.client import login, receipts, room, sendtodevice
+from synapse.types import JsonDict, RoomStreamToken
+from synapse.util import json_encoder
+from synapse.util.stringutils import random_string
 
+from tests import unittest
 from tests.test_utils import make_awaitable
 from tests.utils import MockClock
 
-from .. import unittest
-
 
 class AppServiceHandlerTestCase(unittest.TestCase):
     """Tests the ApplicationServicesHandler."""
@@ -253,20 +259,24 @@ async def get_3pe_protocol(service, unusedProtocol):
             },
         )
 
-    def test_notify_interested_services_ephemeral(self):
+    def test_notify_interested_services_ephemeral_read_receipt(self):
         """
-        Test sending ephemeral events to the appservice handler are scheduled
+        Test sending read receipts to the appservice handler are scheduled
         to be pushed out to interested appservices, and that the stream ID is
         updated accordingly.
         """
+        # Create an application service that is guaranteed to be interested in
+        # any new events
         interested_service = self._mkservice(is_interested=True)
         services = [interested_service]
-
         self.mock_store.get_app_services.return_value = services
+
+        # State that this application service has received up until stream ID 579
         self.mock_store.get_type_stream_id_for_appservice.return_value = make_awaitable(
             579
         )
 
+        # Set up a dummy event that should be sent to the application service
         event = Mock(event_id="event_1")
         self.event_source.sources.receipt.get_new_events_as.return_value = (
             make_awaitable(([event], None))
@@ -321,3 +331,272 @@ def _mkservice_alias(self, is_interested_in_alias):
         service.token = "mock_service_token"
         service.url = "mock_service_url"
         return service
+
+
+class ApplicationServiceEphemeralEventsTestCase(unittest.HomeserverTestCase):
+    servlets = [
+        synapse.rest.admin.register_servlets_for_client_rest_resource,
+        login.register_servlets,
+        room.register_servlets,
+        sendtodevice.register_servlets,
+        receipts.register_servlets,
+    ]
+
+    def prepare(self, reactor, clock, hs):
+        # Mock the application service scheduler so that we can track any
+        # outgoing transactions
+        self.mock_scheduler = Mock()
+        self.mock_scheduler.submit_ephemeral_events_for_as = Mock()
+
+        hs.get_application_service_handler().scheduler = self.mock_scheduler
+
+        self.device1 = "device1"
+        self.user1 = self.register_user("user1", "password")
+        self.token1 = self.login("user1", "password", self.device1)
+
+        self.device2 = "device2"
+        self.user2 = self.register_user("user2", "password")
+        self.token2 = self.login("user2", "password", self.device2)
+
+    @unittest.override_config(
+        {"experimental_features": {"msc2409_to_device_messages_enabled": True}}
+    )
+    def test_application_services_receive_local_to_device(self):
+        """
+        Test that when a user sends a to-device message to another user, and
+        that is in an application service's user namespace, that application
+        service will receive it.
+        """
+        (
+            interested_services,
+            _,
+        ) = self._register_interested_and_uninterested_application_services()
+        interested_service = interested_services[0]
+
+        # Have user1 send a to-device message to user2
+        message_content = {"some_key": "some really interesting value"}
+        chan = self.make_request(
+            "PUT",
+            "/_matrix/client/r0/sendToDevice/m.room_key_request/3",
+            content={"messages": {self.user2: {self.device2: message_content}}},
+            access_token=self.token1,
+        )
+        self.assertEqual(chan.code, 200, chan.result)
+
+        # Have user2 send a to-device message to user1
+        chan = self.make_request(
+            "PUT",
+            "/_matrix/client/r0/sendToDevice/m.room_key_request/4",
+            content={"messages": {self.user1: {self.device1: message_content}}},
+            access_token=self.token2,
+        )
+        self.assertEqual(chan.code, 200, chan.result)
+
+        # Check if our application service - that is interested in user2 - received
+        # the to-device message as part of an AS transaction.
+        # Only the user1 -> user2 to-device message should have been forwarded to the AS.
+        #
+        # The uninterested application service should not have been notified at all.
+        self.assertEqual(
+            1, self.mock_scheduler.submit_ephemeral_events_for_as.call_count
+        )
+        service, events = self.mock_scheduler.submit_ephemeral_events_for_as.call_args[
+            0
+        ]
+
+        # Assert that this was the same to-device message that user1 sent
+        self.assertEqual(service, interested_service)
+        self.assertEqual(events[0]["type"], "m.room_key_request")
+        self.assertEqual(events[0]["sender"], self.user1)
+
+        # Additional fields 'to_user_id' and 'to_device_id' specifically for
+        # to-device messages via the AS API
+        self.assertEqual(events[0]["to_user_id"], self.user2)
+        self.assertEqual(events[0]["to_device_id"], self.device2)
+        self.assertEqual(events[0]["content"], message_content)
+
+    @unittest.override_config(
+        {"experimental_features": {"msc2409_to_device_messages_enabled": True}}
+    )
+    def test_application_services_receive_bursts_of_to_device(self):
+        """
+        Test that when a user sends >100 to-device messages at once, any
+        interested AS's will receive them in separate transactions.
+        """
+        (
+            interested_services,
+            _,
+        ) = self._register_interested_and_uninterested_application_services(
+            interested_count=2,
+            uninterested_count=2,
+        )
+
+        to_device_message_content = {
+            "some key": "some interesting value",
+        }
+
+        # We need to send a large burst of to-device messages. We also would like to
+        # include them all in the same application service transaction so that we can
+        # test large transactions.
+        #
+        # To do this, we can send a single to-device message to many user devices at
+        # once. However, registering 100+ devices will make this test slow.
+        #
+        # So instead, let's insert some to-device messages directly into the inbox
+        # intended for some dummy devices.
+        #
+        # We insert number_of_messages - 1, as user2 already has one device. We'll then
+        # send a final to-device message to the real device, which will also kick off
+        # an AS transaction (as just inserting messages into the DB won't).
+        number_of_messages = 150
+        messages = {
+            self.user2: {
+                f"device_{num}": to_device_message_content
+                for num in range(number_of_messages - 1)
+            }
+        }
+        # Seed the device_inbox table with to-device messages intended for user2
+        next_device_inbox_stream_id = self.get_success(
+            self.hs.get_datastore()._device_inbox_id_gen.get_next().__aenter__()
+        )
+        self.get_success(
+            self.hs.get_datastore().db_pool.simple_insert_many(
+                desc="test_application_services_receive_burst_of_to_device",
+                table="device_inbox",
+                values=[
+                    {
+                        "user_id": user_id,
+                        "device_id": device_id,
+                        "stream_id": next_device_inbox_stream_id,
+                        "message_json": json_encoder.encode(message_json),
+                        "instance_name": "master",
+                    }
+                    for user_id, messages_by_device in messages.items()
+                    for device_id, message_json in messages_by_device.items()
+                ],
+            )
+        )
+
+        # Now have user1 send a final to-device message to user2. All unsent
+        # to-device messages should be sent to any application services
+        # interested in user2.
+        chan = self.make_request(
+            "PUT",
+            "/_matrix/client/r0/sendToDevice/m.room_key_request/4",
+            content={
+                "messages": {self.user2: {self.device2: to_device_message_content}}
+            },
+            access_token=self.token1,
+        )
+        self.assertEqual(chan.code, 200, chan.result)
+
+        # Count the total number of to-device messages that were sent out per-service.
+        # Ensure that we only sent to-device messages to interested services, and that
+        # each interested service received the full count of to-device messages.
+        service_id_to_message_count: Dict[str, int] = {}
+        self.assertGreater(
+            self.mock_scheduler.submit_ephemeral_events_for_as.call_count, 0
+        )
+        for call in self.mock_scheduler.submit_ephemeral_events_for_as.call_args_list:
+            service, events = call[0]
+
+            # Check that this was made to an interested service
+            self.assertIn(service, interested_services)
+
+            # Add to the count of messages for this application service
+            service_id_to_message_count.setdefault(service.id, 0)
+            service_id_to_message_count[service.id] += len(events)
+
+        # Assert that each interested service received the full count of messages
+        for count in service_id_to_message_count.values():
+            self.assertEqual(count, number_of_messages)
+
+    def _register_interested_and_uninterested_application_services(
+        self,
+        interested_count: int = 1,
+        uninterested_count: int = 1,
+    ) -> Tuple[List[ApplicationService], List[ApplicationService]]:
+        """
+        Create application services with and without exclusive interest
+        in user2.
+
+        Args:
+            interested_count: The number of application services to create
+                and register with exclusive interest.
+            uninterested_count: The number of application services to create
+                and register without any interest.
+
+        Returns:
+            A two-tuple containing:
+                * Interested application services
+                * Uninterested application services
+        """
+        # Create an application service with exclusive interest in user2
+        interested_services = []
+        uninterested_services = []
+        for _ in range(interested_count):
+            interested_service = self._make_application_service(
+                namespaces={
+                    ApplicationService.NS_USERS: [
+                        {
+                            "regex": "@user2:.+",
+                            "exclusive": True,
+                        }
+                    ],
+                },
+            )
+            interested_services.append(interested_service)
+
+        for _ in range(uninterested_count):
+            uninterested_services.append(self._make_application_service())
+
+        # Register this application service, along with another, uninterested one
+        services = [
+            *uninterested_services,
+            *interested_services,
+        ]
+        self.hs.get_datastore().get_app_services = Mock(return_value=services)
+
+        return interested_services, uninterested_services
+
+    def _make_application_service(
+        self,
+        namespaces: Optional[Dict[str, Iterable[Dict]]] = None,
+    ) -> ApplicationService:
+        return ApplicationService(
+            token=None,
+            hostname="example.com",
+            id=random_string(10),
+            sender="@as:example.com",
+            rate_limited=False,
+            namespaces=namespaces,
+            supports_ephemeral=True,
+        )
+
+    def _event_id_from_read_receipt(self, read_receipt_dict: JsonDict):
+        """
+        Extracts the first event ID from a read receipt. Read receipt dictionaries
+        are in the form:
+
+        {
+            'type': 'm.receipt',
+            'room_id': '!PEzCqHyycBVxqMKIjI:test',
+            'content': {
+                '$DETIeTEH651c1N7sP_j-YZiaQqCaayHhYwmhZDVWDY8': {  # We want this
+                    'm.read': {
+                        '@user1:test': {
+                            'ts': 1300,
+                            'hidden': False
+                        }
+                    }
+                }
+            }
+        }
+
+        Args:
+            read_receipt_dict: The dictionary returned from a POST read receipt call.
+
+        Returns:
+            The (first) event ID the read receipt refers to.
+        """
+        return list(read_receipt_dict["content"].keys())[0]

tests/rest/client/utils.py

@@ -230,7 +230,7 @@ def send(
         custom_headers: Optional[
             Iterable[Tuple[Union[bytes, str], Union[bytes, str]]]
         ] = None,
-    ):
+    ) -> JsonDict:
         if body is None:
             body = "body_text_here"
 
@@ -257,7 +257,7 @@ def send_event(
         custom_headers: Optional[
             Iterable[Tuple[Union[bytes, str], Union[bytes, str]]]
         ] = None,
-    ):
+    ) -> JsonDict:
         if txn_id is None:
             txn_id = "m%s" % (str(time.time()))
 

tests/utils.py

@@ -144,6 +144,7 @@ def default_config(name, parse=False):
         "admin_contact": None,
         "rc_message": {"per_second": 10000, "burst_count": 10000},
         "rc_registration": {"per_second": 10000, "burst_count": 10000},
+        "rc_key_requests": {"per_second": 10000, "burst_count": 10000},
         "rc_login": {
             "address": {"per_second": 10000, "burst_count": 10000},
             "account": {"per_second": 10000, "burst_count": 10000},