Test ignored users.

tests/rest/client/test_relations.py

@@ -1796,4 +1796,35 @@ def test_include(self) -> None:
         thread_roots = [ev["event_id"] for ev in channel.json_body["chunk"]]
         self.assertEqual(thread_roots, [thread_2, thread_1], channel.json_body)
 
-    # XXX Test ignoring users.
+    @unittest.override_config({"experimental_features": {"msc3856_enabled": True}})
+    def test_ignored_user(self) -> None:
+        """Events from ignored users should be ignored."""
+        # Thread 1 has a reply from an ignored user.
+        thread_1 = self.parent_id
+        self._send_relation(
+            RelationTypes.THREAD, "m.room.test", access_token=self.user2_token
+        )
+
+        # Thread 2 is created by an ignored user.
+        res = self.helper.send(self.room, body="Thread Root!", tok=self.user2_token)
+        thread_2 = res["event_id"]
+        self._send_relation(RelationTypes.THREAD, "m.room.test", parent_id=thread_2)
+
+        # Ignore user2.
+        self.get_success(
+            self.store.add_account_data_for_user(
+                self.user_id,
+                AccountDataTypes.IGNORED_USER_LIST,
+                {"ignored_users": {self.user2_id: {}}},
+            )
+        )
+
+        # Only thread 1 is returned.
+        channel = self.make_request(
+            "GET",
+            f"/_matrix/client/unstable/org.matrix.msc3856/rooms/{self.room}/threads",
+            access_token=self.user_token,
+        )
+        self.assertEquals(200, channel.code, channel.json_body)
+        thread_roots = [ev["event_id"] for ev in channel.json_body["chunk"]]
+        self.assertEqual(thread_roots, [thread_1], channel.json_body)