Add query parameter ts to allow appservices set the origin_server_ts for state events. (#11866)

MSC3316 declares that both /rooms/{roomId}/send and /rooms/{roomId}/state
should accept a ts parameter for appservices. This change expands support
to /state and adds tests.

tests/rest/client/test_rooms.py

@@ -20,7 +20,7 @@
 import json
 from http import HTTPStatus
 from typing import Any, Dict, Iterable, List, Optional, Tuple, Union
-from unittest.mock import Mock, call
+from unittest.mock import Mock, call, patch
 from urllib import parse as urlparse
 
 from parameterized import param, parameterized
@@ -39,9 +39,10 @@ from synapse.api.constants import (
     RoomTypes,
 )
 from synapse.api.errors import Codes, HttpResponseException
+from synapse.appservice import ApplicationService
 from synapse.handlers.pagination import PurgeStatus
 from synapse.rest import admin
-from synapse.rest.client import account, directory, login, profile, room, sync
+from synapse.rest.client import account, directory, login, profile, register, room, sync
 from synapse.server import HomeServer
 from synapse.types import JsonDict, RoomAlias, UserID, create_requester
 from synapse.util import Clock
@@ -1252,6 +1253,120 @@ class RoomJoinTestCase(RoomBase):
         )
 
 
+class RoomAppserviceTsParamTestCase(unittest.HomeserverTestCase):
+    servlets = [
+        room.register_servlets,
+        synapse.rest.admin.register_servlets,
+        register.register_servlets,
+    ]
+
+    def prepare(self, reactor: MemoryReactor, clock: Clock, hs: HomeServer) -> None:
+        self.appservice_user, _ = self.register_appservice_user(
+            "as_user_potato", self.appservice.token
+        )
+
+        # Create a room as the appservice user.
+        args = {
+            "access_token": self.appservice.token,
+            "user_id": self.appservice_user,
+        }
+        channel = self.make_request(
+            "POST",
+            f"/_matrix/client/r0/createRoom?{urlparse.urlencode(args)}",
+            content={"visibility": "public"},
+        )
+
+        assert channel.code == 200
+        self.room = channel.json_body["room_id"]
+
+        self.main_store = self.hs.get_datastores().main
+
+    def make_homeserver(self, reactor: MemoryReactor, clock: Clock) -> HomeServer:
+        config = self.default_config()
+
+        self.appservice = ApplicationService(
+            token="i_am_an_app_service",
+            id="1234",
+            namespaces={"users": [{"regex": r"@as_user.*", "exclusive": True}]},
+            # Note: this user does not have to match the regex above
+            sender="@as_main:test",
+        )
+
+        mock_load_appservices = Mock(return_value=[self.appservice])
+        with patch(
+            "synapse.storage.databases.main.appservice.load_appservices",
+            mock_load_appservices,
+        ):
+            hs = self.setup_test_homeserver(config=config)
+        return hs
+
+    def test_send_event_ts(self) -> None:
+        """Test sending a non-state event with a custom timestamp."""
+        ts = 1
+
+        url_params = {
+            "user_id": self.appservice_user,
+            "ts": ts,
+        }
+        channel = self.make_request(
+            "PUT",
+            path=f"/_matrix/client/r0/rooms/{self.room}/send/m.room.message/1234?"
+            + urlparse.urlencode(url_params),
+            content={"body": "test", "msgtype": "m.text"},
+            access_token=self.appservice.token,
+        )
+        self.assertEqual(channel.code, 200, channel.json_body)
+        event_id = channel.json_body["event_id"]
+
+        # Ensure the event was persisted with the correct timestamp.
+        res = self.get_success(self.main_store.get_event(event_id))
+        self.assertEquals(ts, res.origin_server_ts)
+
+    def test_send_state_event_ts(self) -> None:
+        """Test sending a state event with a custom timestamp."""
+        ts = 1
+
+        url_params = {
+            "user_id": self.appservice_user,
+            "ts": ts,
+        }
+        channel = self.make_request(
+            "PUT",
+            path=f"/_matrix/client/r0/rooms/{self.room}/state/m.room.name?"
+            + urlparse.urlencode(url_params),
+            content={"name": "test"},
+            access_token=self.appservice.token,
+        )
+        self.assertEqual(channel.code, 200, channel.json_body)
+        event_id = channel.json_body["event_id"]
+
+        # Ensure the event was persisted with the correct timestamp.
+        res = self.get_success(self.main_store.get_event(event_id))
+        self.assertEquals(ts, res.origin_server_ts)
+
+    def test_send_membership_event_ts(self) -> None:
+        """Test sending a membership event with a custom timestamp."""
+        ts = 1
+
+        url_params = {
+            "user_id": self.appservice_user,
+            "ts": ts,
+        }
+        channel = self.make_request(
+            "PUT",
+            path=f"/_matrix/client/r0/rooms/{self.room}/state/m.room.member/{self.appservice_user}?"
+            + urlparse.urlencode(url_params),
+            content={"membership": "join", "display_name": "test"},
+            access_token=self.appservice.token,
+        )
+        self.assertEqual(channel.code, 200, channel.json_body)
+        event_id = channel.json_body["event_id"]
+
+        # Ensure the event was persisted with the correct timestamp.
+        res = self.get_success(self.main_store.get_event(event_id))
+        self.assertEquals(ts, res.origin_server_ts)
+
+
 class RoomJoinRatelimitTestCase(RoomBase):
     user_id = "@sid1:red"