Add ephemeral messages support (MSC2228) (#6409)

Implement part [MSC2228](https://github.com/matrix-org/matrix-doc/pull/2228). The parts that differ are:

* the feature is hidden behind a configuration flag (`enable_ephemeral_messages`)
* self-destruction doesn't happen for state events
* only implement support for the `m.self_destruct_after` field (not the `m.self_destruct` one)
* doesn't send synthetic redactions to clients because for this specific case we consider the clients to be able to destroy an event themselves, instead we just censor it (by pruning its JSON) in the database

1 files changed, 101 insertions, 0 deletions

diff --git a/tests/rest/client/test_ephemeral_message.py b/tests/rest/client/test_ephemeral_message.py
new file mode 100644
index 0000000000..5e9c07ebf3
--- /dev/null
+++ b/tests/rest/client/test_ephemeral_message.py
@@ -0,0 +1,101 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 New Vector Ltd
+#
+# 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.api.constants import EventContentFields, EventTypes
+from synapse.rest import admin
+from synapse.rest.client.v1 import room
+
+from tests import unittest
+
+
+class EphemeralMessageTestCase(unittest.HomeserverTestCase):
+
+    user_id = "@user:test"
+
+    servlets = [
+        admin.register_servlets,
+        room.register_servlets,
+    ]
+
+    def make_homeserver(self, reactor, clock):
+        config = self.default_config()
+
+        config["enable_ephemeral_messages"] = True
+
+        self.hs = self.setup_test_homeserver(config=config)
+        return self.hs
+
+    def prepare(self, reactor, clock, homeserver):
+        self.room_id = self.helper.create_room_as(self.user_id)
+
+    def test_message_expiry_no_delay(self):
+        """Tests that sending a message sent with a m.self_destruct_after field set to the
+        past results in that event being deleted right away.
+        """
+        # Send a message in the room that has expired. From here, the reactor clock is
+        # at 200ms, so 0 is in the past, and even if that wasn't the case and the clock
+        # is at 0ms the code path is the same if the event's expiry timestamp is the
+        # current timestamp.
+        res = self.helper.send_event(
+            room_id=self.room_id,
+            type=EventTypes.Message,
+            content={
+                "msgtype": "m.text",
+                "body": "hello",
+                EventContentFields.SELF_DESTRUCT_AFTER: 0,
+            },
+        )
+        event_id = res["event_id"]
+
+        # Check that we can't retrieve the content of the event.
+        event_content = self.get_event(self.room_id, event_id)["content"]
+        self.assertFalse(bool(event_content), event_content)
+
+    def test_message_expiry_delay(self):
+        """Tests that sending a message with a m.self_destruct_after field set to the
+        future results in that event not being deleted right away, but advancing the
+        clock to after that expiry timestamp causes the event to be deleted.
+        """
+        # Send a message in the room that'll expire in 1s.
+        res = self.helper.send_event(
+            room_id=self.room_id,
+            type=EventTypes.Message,
+            content={
+                "msgtype": "m.text",
+                "body": "hello",
+                EventContentFields.SELF_DESTRUCT_AFTER: self.clock.time_msec() + 1000,
+            },
+        )
+        event_id = res["event_id"]
+
+        # Check that we can retrieve the content of the event before it has expired.
+        event_content = self.get_event(self.room_id, event_id)["content"]
+        self.assertTrue(bool(event_content), event_content)
+
+        # Advance the clock to after the deletion.
+        self.reactor.advance(1)
+
+        # Check that we can't retrieve the content of the event anymore.
+        event_content = self.get_event(self.room_id, event_id)["content"]
+        self.assertFalse(bool(event_content), event_content)
+
+    def get_event(self, room_id, event_id, expected_code=200):
+        url = "/_matrix/client/r0/rooms/%s/event/%s" % (room_id, event_id)
+
+        request, channel = self.make_request("GET", url)
+        self.render(request)
+
+        self.assertEqual(channel.code, expected_code, channel.result)
+
+        return channel.json_body