From 4a754ded5f13fd482b46a8ca90c4b7e2e632726b Mon Sep 17 00:00:00 2001
From: Krille <c.kussowski@famedly.com>
Date: Fri, 4 Oct 2024 13:41:35 +0200
Subject: [PATCH] fix: (BREAKING) Change power level without changing memory

The problem here is that we
have not created a deep copy
of the power level map. By using .copy() we create a
deep copy now.
---
 lib/src/room.dart   | 27 ++++++++++++++++++---------
 test/room_test.dart | 14 ++++++++++++++
 2 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/lib/src/room.dart b/lib/src/room.dart
index 9a1fe35e..bdef55e4 100644
--- a/lib/src/room.dart
+++ b/lib/src/room.dart
@@ -1189,22 +1189,31 @@ class Room {
   /// Set the power level of the user with the [userID] to the value [power].
   /// Returns the event ID of the new state event. If there is no known
   /// power level event, there might something broken and this returns null.
-  Future<String> setPower(String userID, int power) async {
-    final powerMap = Map<String, Object?>.from(
-      getState(EventTypes.RoomPowerLevels)?.content ?? {},
-    );
+  /// Please note, that you need to await the power level state from sync before
+  /// the changes are actually applied. Especially if you want to set multiple
+  /// power levels at once, you need to await each change in the sync, to not
+  /// override those.
+  Future<String> setPower(String userId, int power) async {
+    final powerLevelMapCopy =
+        getState(EventTypes.RoomPowerLevels)?.content.copy() ?? {};
 
-    final usersPowerMap = powerMap['users'] is Map<String, Object?>
-        ? powerMap['users'] as Map<String, Object?>
-        : (powerMap['users'] = <String, Object?>{});
+    var users = powerLevelMapCopy['users'];
 
-    usersPowerMap[userID] = power;
+    if (users is! Map<String, Object?>) {
+      if (users != null) {
+        Logs().v(
+            'Repairing Power Level "users" has the wrong type "${powerLevelMapCopy['users'].runtimeType}"');
+      }
+      users = powerLevelMapCopy['users'] = <String, Object?>{};
+    }
+
+    users[userId] = power;
 
     return await client.setRoomStateWithKey(
       id,
       EventTypes.RoomPowerLevels,
       '',
-      powerMap,
+      powerLevelMapCopy,
     );
   }
 
diff --git a/test/room_test.dart b/test/room_test.dart
index 99c8f197..6edbdda5 100644
--- a/test/room_test.dart
+++ b/test/room_test.dart
@@ -787,6 +787,20 @@ void main() {
       await room.invite('Testname');
     });
 
+    test('setPower', () async {
+      final powerLevelMap =
+          room.getState(EventTypes.RoomPowerLevels, '')!.content.copy();
+
+      // Request to fake api does not update anything:
+      await room.setPower('@bob:fakeServer.notExisting', 100);
+
+      // Original power level map has not changed:
+      expect(
+        powerLevelMap,
+        room.getState(EventTypes.RoomPowerLevels, '')!.content.copy(),
+      );
+    });
+
     test('getParticipants', () async {
       var userList = room.getParticipants();
       expect(userList.length, 4);