make /devices return a list

Turns out I specced this to return a list of devices rather than a dict of them

synapse/handlers/device.py

@@ -79,17 +79,17 @@ class DeviceHandler(BaseHandler):
         Args:
             user_id (str):
         Returns:
-            defer.Deferred: dict[str, dict[str, X]]: map from device_id to
-            info on the device
+            defer.Deferred: list[dict[str, X]]: info on each device
         """
 
-        devices = yield self.store.get_devices_by_user(user_id)
+        device_map = yield self.store.get_devices_by_user(user_id)
 
         ips = yield self.store.get_last_client_ip_by_device(
-            devices=((user_id, device_id) for device_id in devices.keys())
+            devices=((user_id, device_id) for device_id in device_map.keys())
         )
 
-        for device in devices.values():
+        devices = device_map.values()
+        for device in devices:
             _update_device_from_client_ips(device, ips)
 
         defer.returnValue(devices)

tests/handlers/test_device.py

@@ -84,28 +84,31 @@ class DeviceTestCase(unittest.TestCase):
         yield self._record_users()
 
         res = yield self.handler.get_devices_by_user(user1)
-        self.assertEqual(3, len(res.keys()))
+        self.assertEqual(3, len(res))
+        device_map = {
+            d["device_id"]: d for d in res
+        }
         self.assertDictContainsSubset({
             "user_id": user1,
             "device_id": "xyz",
             "display_name": "display 0",
             "last_seen_ip": None,
             "last_seen_ts": None,
-        }, res["xyz"])
+        }, device_map["xyz"])
         self.assertDictContainsSubset({
             "user_id": user1,
             "device_id": "fco",
             "display_name": "display 1",
             "last_seen_ip": "ip1",
             "last_seen_ts": 1000000,
-        }, res["fco"])
+        }, device_map["fco"])
         self.assertDictContainsSubset({
             "user_id": user1,
             "device_id": "abc",
             "display_name": "display 2",
             "last_seen_ip": "ip3",
             "last_seen_ts": 3000000,
-        }, res["abc"])
+        }, device_map["abc"])
 
     @defer.inlineCallbacks
     def test_get_device(self):