[tests] add test for prior bugfix

tests/gateway/events.py

@@ -18,3 +18,25 @@ def test_from_dispatch():
 
 def test_event_creation(benchmark):
     benchmark(create_resumed_payload)
+
+
+def test_guild_role_guild_id_attach():
+    event = GatewayEvent.from_dispatch(None, {
+        't': 'GUILD_ROLE_CREATE',
+        'd': {
+            'role': {
+                'id': 1,
+                'name': 'test',
+                'color': 1,
+                'hoist': True,
+                'position': 0,
+                'permissions': 0,
+                'managed': False,
+                'mentionable': False,
+            },
+            'guild_id': 2,
+        }
+    })
+
+    assert event.guild_id == 2
+    assert event.role.guild_id == 2