Support the MSC3715 for `/relations`. (#11941)

This adds an unstable org.matrix.msc3715.dir parameter
which acts like dir on /mesages.

1 files changed, 31 insertions, 6 deletions

diff --git a/tests/rest/client/test_relations.py b/tests/rest/client/test_relations.py
index 9768fb2971..de80aca037 100644
--- a/tests/rest/client/test_relations.py
+++ b/tests/rest/client/test_relations.py
@@ -169,24 +169,28 @@ class RelationsTestCase(unittest.HomeserverTestCase):
         """Tests that calling pagination API correctly the latest relations."""
         channel = self._send_relation(RelationTypes.ANNOTATION, "m.reaction", "a")
         self.assertEquals(200, channel.code, channel.json_body)
+        first_annotation_id = channel.json_body["event_id"]
 
         channel = self._send_relation(RelationTypes.ANNOTATION, "m.reaction", "b")
         self.assertEquals(200, channel.code, channel.json_body)
-        annotation_id = channel.json_body["event_id"]
+        second_annotation_id = channel.json_body["event_id"]
 
         channel = self.make_request(
             "GET",
-            "/_matrix/client/unstable/rooms/%s/relations/%s?limit=1"
-            % (self.room, self.parent_id),
+            f"/_matrix/client/unstable/rooms/{self.room}/relations/{self.parent_id}?limit=1",
             access_token=self.user_token,
         )
         self.assertEquals(200, channel.code, channel.json_body)
 
-        # We expect to get back a single pagination result, which is the full
-        # relation event we sent above.
+        # We expect to get back a single pagination result, which is the latest
+        # full relation event we sent above.
         self.assertEquals(len(channel.json_body["chunk"]), 1, channel.json_body)
         self.assert_dict(
-            {"event_id": annotation_id, "sender": self.user_id, "type": "m.reaction"},
+            {
+                "event_id": second_annotation_id,
+                "sender": self.user_id,
+                "type": "m.reaction",
+            },
             channel.json_body["chunk"][0],
         )
 
@@ -201,6 +205,27 @@ class RelationsTestCase(unittest.HomeserverTestCase):
             channel.json_body.get("next_batch"), str, channel.json_body
         )
 
+        # Request the relations again, but with a different direction.
+        channel = self.make_request(
+            "GET",
+            f"/_matrix/client/unstable/rooms/{self.room}/relations"
+            f"/{self.parent_id}?limit=1&org.matrix.msc3715.dir=f",
+            access_token=self.user_token,
+        )
+        self.assertEquals(200, channel.code, channel.json_body)
+
+        # We expect to get back a single pagination result, which is the earliest
+        # full relation event we sent above.
+        self.assertEquals(len(channel.json_body["chunk"]), 1, channel.json_body)
+        self.assert_dict(
+            {
+                "event_id": first_annotation_id,
+                "sender": self.user_id,
+                "type": "m.reaction",
+            },
+            channel.json_body["chunk"][0],
+        )
+
     def _stream_token_to_relation_token(self, token: str) -> str:
         """Convert a StreamToken into a legacy token (RelationPaginationToken)."""
         room_key = self.get_success(StreamToken.from_string(self.store, token)).room_key