Delete messages from device_inbox table when deleting device (#10969)

Fixes: #9346

tests/storage/databases/main/test_deviceinbox.py

@@ -0,0 +1,90 @@
+# Copyright 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.
+# 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.rest import admin
+from synapse.rest.client import devices
+
+from tests.unittest import HomeserverTestCase
+
+
+class DeviceInboxBackgroundUpdateStoreTestCase(HomeserverTestCase):
+
+    servlets = [
+        admin.register_servlets,
+        devices.register_servlets,
+    ]
+
+    def prepare(self, reactor, clock, hs):
+        self.store = hs.get_datastore()
+        self.user_id = self.register_user("foo", "pass")
+
+    def test_background_remove_deleted_devices_from_device_inbox(self):
+        """Test that the background task to delete old device_inboxes works properly."""
+
+        # create a valid device
+        self.get_success(
+            self.store.store_device(self.user_id, "cur_device", "display_name")
+        )
+
+        # Add device_inbox to devices
+        self.get_success(
+            self.store.db_pool.simple_insert(
+                "device_inbox",
+                {
+                    "user_id": self.user_id,
+                    "device_id": "cur_device",
+                    "stream_id": 1,
+                    "message_json": "{}",
+                },
+            )
+        )
+        self.get_success(
+            self.store.db_pool.simple_insert(
+                "device_inbox",
+                {
+                    "user_id": self.user_id,
+                    "device_id": "old_device",
+                    "stream_id": 2,
+                    "message_json": "{}",
+                },
+            )
+        )
+
+        # Insert and run the background update.
+        self.get_success(
+            self.store.db_pool.simple_insert(
+                "background_updates",
+                {
+                    "update_name": "remove_deleted_devices_from_device_inbox",
+                    "progress_json": "{}",
+                },
+            )
+        )
+
+        # ... and tell the DataStore that it hasn't finished all updates yet
+        self.store.db_pool.updates._all_done = False
+
+        self.wait_for_background_updates()
+
+        # Make sure the background task deleted old device_inbox
+        res = self.get_success(
+            self.store.db_pool.simple_select_onecol(
+                table="device_inbox",
+                keyvalues={},
+                retcol="device_id",
+                desc="get_device_id_from_device_inbox",
+            )
+        )
+        self.assertEqual(1, len(res))
+        self.assertEqual(res[0], "cur_device")