chore: enable discarded_futures lint

BREAKING CHANGE: This changes the runInRoot method to not return a
future. As a user, if you need the result of an async computation passed
to runInRoot, please await it directly. Also the KeyVerification start
and a few call methods now return a future.

analysis_options.yaml

@@ -6,6 +6,8 @@ linter:
     always_use_package_imports: true
     avoid_bool_literals_in_conditional_expressions: true
     avoid_print: true
+    cancel_subscriptions: true
+    discarded_futures: true
     non_constant_identifier_names: false # seems to wrongly diagnose static const variables
     prefer_final_in_for_each: true
     prefer_final_locals: true

lib/encryption/encryption.dart

@@ -100,11 +100,12 @@ class Encryption {
 
   void handleDeviceOneTimeKeysCount(
       Map<String, int>? countJson, List<String>? unusedFallbackKeyTypes) {
-    runInRoot(() => olmManager.handleDeviceOneTimeKeysCount(
+    runInRoot(() async => olmManager.handleDeviceOneTimeKeysCount(
         countJson, unusedFallbackKeyTypes));
   }
 
   void onSync() {
+    // ignore: discarded_futures
     keyVerificationManager.cleanup();
   }
 
@@ -118,30 +119,25 @@ class Encryption {
         .contains(event.type)) {
       // "just" room key request things. We don't need these asap, so we handle
       // them in the background
-      // ignore: unawaited_futures
       runInRoot(() => keyManager.handleToDeviceEvent(event));
     }
     if (event.type == EventTypes.Dummy) {
       // the previous device just had to create a new olm session, due to olm session
       // corruption. We want to try to send it the last message we just sent it, if possible
-      // ignore: unawaited_futures
       runInRoot(() => olmManager.handleToDeviceEvent(event));
     }
     if (event.type.startsWith('m.key.verification.')) {
       // some key verification event. No need to handle it now, we can easily
       // do this in the background
 
-      // ignore: unawaited_futures
       runInRoot(() => keyVerificationManager.handleToDeviceEvent(event));
     }
     if (event.type.startsWith('m.secret.')) {
       // some ssss thing. We can do this in the background
-      // ignore: unawaited_futures
       runInRoot(() => ssss.handleToDeviceEvent(event));
     }
     if (event.sender == client.userID) {
       // maybe we need to re-try SSSS secrets
-      // ignore: unawaited_futures
       runInRoot(() => ssss.periodicallyRequestMissingCache());
     }
   }
@@ -157,14 +153,11 @@ class Encryption {
             update.content['content']['msgtype']
                 .startsWith('m.key.verification.'))) {
       // "just" key verification, no need to do this in sync
-
-      // ignore: unawaited_futures
       runInRoot(() => keyVerificationManager.handleEventUpdate(update));
     }
     if (update.content['sender'] == client.userID &&
         update.content['unsigned']?['transaction_id'] == null) {
       // maybe we need to re-try SSSS secrets
-      // ignore: unawaited_futures
       runInRoot(() => ssss.periodicallyRequestMissingCache());
     }
   }
@@ -239,6 +232,7 @@ class Encryption {
         // the entry should always exist. In the case it doesn't, the following
         // line *could* throw an error. As that is a future, though, and we call
         // it un-awaited here, nothing happens, which is exactly the result we want
+        // ignore: discarded_futures
         client.database?.updateInboundGroupSessionIndexes(
             json.encode(inboundGroupSession.indexes), roomId, sessionId);
       }
@@ -252,7 +246,7 @@ class Encryption {
                       ?.session_id() ??
                   '') ==
               content.sessionId) {
-        runInRoot(() =>
+        runInRoot(() async =>
             keyManager.clearOrUseOutboundGroupSession(roomId, wipe: true));
       }
       if (canRequestSession) {

lib/encryption/key_manager.dart

@@ -244,7 +244,8 @@ class KeyManager {
         !client.isUnknownSession) {
       // do e2ee recovery
       _requestedSessionIds.add(requestIdent);
-      runInRoot(() => request(
+
+      runInRoot(() async => request(
             room,
             sessionId,
             senderKey,
@@ -775,8 +776,8 @@ class KeyManager {
   Future<void>? _uploadingFuture;
 
   void startAutoUploadKeys() {
-    _uploadKeysOnSync = encryption.client.onSync.stream
+    _uploadKeysOnSync = encryption.client.onSync.stream.listen(
-        .listen((_) => uploadInboundGroupSessions(skipIfInProgress: true));
+        (_) async => uploadInboundGroupSessions(skipIfInProgress: true));
   }
 
   /// This task should be performed after sync processing but should not block
@@ -1064,6 +1065,7 @@ class KeyManager {
   StreamSubscription<SyncUpdate>? _uploadKeysOnSync;
 
   void dispose() {
+    // ignore: discarded_futures
     _uploadKeysOnSync?.cancel();
     for (final sess in _outboundGroupSessions.values) {
       sess.dispose();

lib/encryption/olm_manager.dart

@@ -396,20 +396,24 @@ class OlmManager {
     final device = client.userDeviceKeys[event.sender]?.deviceKeys.values
         .firstWhereOrNull((d) => d.curve25519Key == senderKey);
     final existingSessions = olmSessions[senderKey];
-    Future<void> updateSessionUsage([OlmSession? session]) =>
+    Future<void> updateSessionUsage([OlmSession? session]) async {
-        runInRoot(() async {
+      try {
-          if (session != null) {
+        if (session != null) {
-            session.lastReceived = DateTime.now();
+          session.lastReceived = DateTime.now();
-            await storeOlmSession(session);
+          await storeOlmSession(session);
-          }
+        }
-          if (device != null) {
+        if (device != null) {
-            device.lastActive = DateTime.now();
+          device.lastActive = DateTime.now();
-            await encryption.olmDatabase?.setLastActiveUserDeviceKey(
+          await encryption.olmDatabase?.setLastActiveUserDeviceKey(
-                device.lastActive.millisecondsSinceEpoch,
+              device.lastActive.millisecondsSinceEpoch,
-                device.userId,
+              device.userId,
-                device.deviceId!);
+              device.deviceId!);
-          }
+        }
-        });
+      } catch (e, s) {
+        Logs().e('Error while updating olm session timestamp', e, s);
+      }
+    }
+
     if (existingSessions != null) {
       for (final session in existingSessions) {
         if (session.session == null) {
@@ -446,14 +450,16 @@ class OlmManager {
         newSession.create_inbound_from(_olmAccount!, senderKey, body);
         _olmAccount!.remove_one_time_keys(newSession);
         await encryption.olmDatabase?.updateClientKeys(pickledOlmAccount!);
+
         plaintext = newSession.decrypt(type, body);
-        await runInRoot(() => storeOlmSession(OlmSession(
+
-              key: client.userID!,
+        await storeOlmSession(OlmSession(
-              identityKey: senderKey,
+          key: client.userID!,
-              sessionId: newSession.session_id(),
+          identityKey: senderKey,
-              session: newSession,
+          sessionId: newSession.session_id(),
-              lastReceived: DateTime.now(),
+          session: newSession,
-            )));
+          lastReceived: DateTime.now(),
+        ));
         await updateSessionUsage();
       } catch (e) {
         newSession.free();
@@ -570,8 +576,6 @@ class OlmManager {
       return _decryptToDeviceEvent(event);
     } catch (_) {
       // okay, the thing errored while decrypting. It is safe to assume that the olm session is corrupt and we should generate a new one
-
-      // ignore: unawaited_futures
       runInRoot(() => restoreOlmSession(event.senderId, senderKey));
 
       rethrow;
@@ -658,14 +662,18 @@ class OlmManager {
     final encryptResult = sess.first.session!.encrypt(json.encode(fullPayload));
     await storeOlmSession(sess.first);
     if (encryption.olmDatabase != null) {
-      await runInRoot(
+      try {
-          () async => encryption.olmDatabase?.setLastSentMessageUserDeviceKey(
+        await encryption.olmDatabase?.setLastSentMessageUserDeviceKey(
-              json.encode({
+            json.encode({
-                'type': type,
+              'type': type,
-                'content': payload,
+              'content': payload,
-              }),
+            }),
-              device.userId,
+            device.userId,
-              device.deviceId!));
+            device.deviceId!);
+      } catch (e, s) {
+        // we can ignore this error, since it would just make us use a different olm session possibly
+        Logs().w('Error while updating olm usage timestamp', e, s);
+      }
     }
     final encryptedBody = <String, dynamic>{
       'algorithm': AlgorithmTypes.olmV1Curve25519AesSha2,

lib/encryption/ssss.dart

@@ -31,7 +31,6 @@ import 'package:matrix/encryption/utils/ssss_cache.dart';
 import 'package:matrix/matrix.dart';
 import 'package:matrix/src/utils/cached_stream_controller.dart';
 import 'package:matrix/src/utils/crypto/crypto.dart' as uc;
-import 'package:matrix/src/utils/run_in_root.dart';
 
 const cacheTypes = <String>{
   EventTypes.CrossSigningSelfSigning,
@@ -722,7 +721,11 @@ class OpenSSSS {
       throw InvalidPassphraseException('Inalid key');
     }
     if (postUnlock) {
-      await runInRoot(() => _postUnlock());
+      try {
+        await _postUnlock();
+      } catch (e, s) {
+        Logs().e('Error during post unlock', e, s);
+      }
     }
   }
 

lib/encryption/utils/base64_unpadded.dart

@@ -3,7 +3,7 @@ import 'dart:typed_data';
 
 /// decodes base64
 ///
-/// Dart's native [base64.decode] requires a padded base64 input String.
+/// Dart's native [base64.decode()] requires a padded base64 input String.
 /// This function allows unpadded base64 too.
 ///
 /// See: https://github.com/dart-lang/sdk/issues/39510

lib/src/client.dart

@@ -1636,7 +1636,7 @@ class Client extends MatrixApi {
   set backgroundSync(bool enabled) {
     _backgroundSync = enabled;
     if (_backgroundSync) {
-      _sync();
+      runInRoot(() async => _sync());
     }
   }
 
@@ -2232,7 +2232,7 @@ class Client extends MatrixApi {
           requestHistoryOnLimitedTimeline) {
         Logs().v(
             'Limited timeline for ${rooms[roomIndex].id} request history now');
-        unawaited(runInRoot(rooms[roomIndex].requestHistory));
+        runInRoot(rooms[roomIndex].requestHistory);
       }
     }
     return room;

lib/src/event.dart

@@ -128,6 +128,7 @@ class Event extends MatrixEvent {
         final json = toJson();
         json['unsigned'] ??= <String, dynamic>{};
         json['unsigned'][messageSendingStatusKey] = EventStatus.error.intValue;
+        // ignore: discarded_futures
         room.client.handleSync(
           SyncUpdate(
             nextBatch: '',
@@ -154,6 +155,7 @@ class Event extends MatrixEvent {
           MessageTypes.File,
         }.contains(messageType) &&
         !room.sendingFilePlaceholders.containsKey(eventId)) {
+      // ignore: discarded_futures
       remove();
     }
   }

lib/src/room.dart

@@ -1620,6 +1620,7 @@ class Room {
       return user.asUser;
     } else {
       if (mxID.isValidMatrixId) {
+        // ignore: discarded_futures
         requestUser(
           mxID,
           ignoreErrors: true,

lib/src/timeline.dart

@@ -300,8 +300,11 @@ class Timeline {
 
   /// Don't forget to call this before you dismiss this object!
   void cancelSubscriptions() {
+    // ignore: discarded_futures
     sub?.cancel();
+    // ignore: discarded_futures
     roomSub?.cancel();
+    // ignore: discarded_futures
     sessionIdReceivedSub?.cancel();
   }
 

lib/src/utils/device_keys_list.dart

@@ -504,7 +504,7 @@ class DeviceKeys extends SignableKey {
     lastActive = DateTime.fromMillisecondsSinceEpoch(0);
   }
 
-  KeyVerification startVerification() {
+  Future<KeyVerification> startVerification() async {
     if (!isValid) {
       throw Exception('setVerification called on invalid key');
     }
@@ -516,7 +516,7 @@ class DeviceKeys extends SignableKey {
     final request = KeyVerification(
         encryption: encryption, userId: userId, deviceId: deviceId!);
 
-    request.start();
+    await request.start();
     encryption.keyVerificationManager.addRequest(request);
     return request;
   }

lib/src/utils/native_implementations.dart

@@ -50,10 +50,9 @@ abstract class NativeImplementations {
     bool retryInDummy = false,
   });
 
-  @override
-
   /// this implementation will catch any non-implemented method
-  dynamic noSuchMethod(Invocation invocation) {
+  @override
+  dynamic noSuchMethod(Invocation invocation) async {
     final dynamic argument = invocation.positionalArguments.single;
     final memberName = invocation.memberName.toString().split('"')[1];
 

lib/src/utils/run_in_root.dart

@@ -20,13 +20,13 @@ import 'dart:async';
 
 import 'package:matrix/matrix.dart';
 
-Future<T?> runInRoot<T>(FutureOr<T> Function() fn) async {
+void runInRoot<T>(FutureOr<T> Function() fn) {
-  return await Zone.root.run(() async {
+  // ignore: discarded_futures
+  Zone.root.run(() async {
     try {
-      return await fn();
+      await fn();
     } catch (e, s) {
       Logs().e('Error thrown in root zone', e, s);
     }
-    return null;
   });
 }

lib/src/utils/uia_request.dart

@@ -52,6 +52,7 @@ class UiaRequest<T> {
   }
 
   UiaRequest({this.onUpdate, required this.request}) {
+    // ignore: discarded_futures
     _run();
   }
 

lib/src/utils/web_worker/native_implementations_web_worker.dart

@@ -37,7 +37,7 @@ class NativeImplementationsWebWorker extends NativeImplementations {
     return completer.future.timeout(timeout);
   }
 
-  void _handleIncomingMessage(MessageEvent event) {
+  Future<void> _handleIncomingMessage(MessageEvent event) async {
     final data = event.data;
     // don't forget handling errors of our second thread...
     if (data['label'] == 'stacktrace') {
@@ -46,12 +46,10 @@ class NativeImplementationsWebWorker extends NativeImplementations {
 
       final error = event.data['error']!;
 
-      Future.value(
+      final stackTrace =
-        onStackTrace.call(event.data['stacktrace'] as String),
+          await onStackTrace.call(event.data['stacktrace'] as String);
-      ).then(
+      completer?.completeError(
-        (stackTrace) => completer?.completeError(
+        WebWorkerError(error: error, stackTrace: stackTrace),
-          WebWorkerError(error: error, stackTrace: stackTrace),
-        ),
       );
     } else {
       final response = WebWorkerData.fromJson(event.data);

lib/src/voip/call.dart

@@ -522,17 +522,18 @@ class CallSession {
     await gotCallFeedsForAnswer(callFeeds);
   }
 
-  void replacedBy(CallSession newCall) {
+  Future<void> replacedBy(CallSession newCall) async {
     if (state == CallState.kWaitLocalMedia) {
       Logs().v('Telling new call to wait for local media');
       newCall.waitForLocalAVStream = true;
     } else if (state == CallState.kCreateOffer ||
         state == CallState.kInviteSent) {
       Logs().v('Handing local stream to new call');
-      newCall.gotCallFeedsForAnswer(getLocalStreams);
+      await newCall.gotCallFeedsForAnswer(getLocalStreams);
     }
     successor = newCall;
     onCallReplaced.add(newCall);
+    // ignore: unawaited_futures
     hangup(CallErrorCode.Replaced, true);
   }
 
@@ -1510,8 +1511,9 @@ class CallSession {
     return pc;
   }
 
-  void createDataChannel(String label, RTCDataChannelInit dataChannelDict) {
+  Future<void> createDataChannel(
-    pc?.createDataChannel(label, dataChannelDict);
+      String label, RTCDataChannelInit dataChannelDict) async {
+    await pc?.createDataChannel(label, dataChannelDict);
   }
 
   Future<void> tryRemoveStopedStreams() async {

lib/src/voip/conn_tester.dart

@@ -45,11 +45,15 @@ class ConnectionTester {
 
     await pc1!.setRemoteDescription(answer);
 
-    void dispose() {
+    Future<void> dispose() async {
-      pc1!.close();
+      await Future.wait([
-      pc1!.dispose();
+        pc1!.close(),
-      pc2!.close();
+        pc2!.close(),
-      pc2!.dispose();
+      ]);
+      await Future.wait([
+        pc1!.dispose(),
+        pc2!.dispose(),
+      ]);
     }
 
     bool connected = false;
@@ -69,6 +73,7 @@ class ConnectionTester {
           .e('[VOIP] ConnectionTester Error while testing TURN server: ', e, s);
     }
 
+    // ignore: unawaited_futures
     dispose();
     return connected;
   }

lib/src/voip/group_call.dart

@@ -232,11 +232,11 @@ class GroupCall {
     this.groupCallId = groupCallId ?? genCallID();
   }
 
-  GroupCall create() {
+  Future<GroupCall> create() async {
     voip.groupCalls[groupCallId] = this;
     voip.groupCalls[room.id] = this;
 
-    client.setRoomStateWithKey(
+    await client.setRoomStateWithKey(
       room.id,
       EventTypes.GroupCallPrefix,
       groupCallId,
@@ -413,6 +413,7 @@ class GroupCall {
     if (localUserMediaStream != null) {
       final oldStream = localUserMediaStream!.stream;
       localUserMediaStream!.setNewStream(stream.stream!);
+      // ignore: discarded_futures
       stopMediaStream(oldStream);
     }
   }

lib/src/voip/voip.dart

@@ -53,6 +53,7 @@ class VoIP {
     for (final room in client.rooms) {
       if (room.activeGroupCallEvents.isNotEmpty) {
         for (final groupCall in room.activeGroupCallEvents) {
+          // ignore: discarded_futures
           createGroupCallFromRoomStateEvent(groupCall,
               emitHandleNewGroupCall: false);
         }
@@ -589,7 +590,7 @@ class VoIP {
       return null;
     }
     final groupId = genCallID();
-    final groupCall = GroupCall(
+    final groupCall = await GroupCall(
       groupCallId: groupId,
       client: client,
       voip: this,

test/client_test.dart

@@ -1137,8 +1137,8 @@ void main() {
           reason: '!5345234235:example.com not found as archived room');
     });
 
-    tearDown(() {
+    tearDown(() async {
-      matrix.dispose(closeDatabase: true);
+      await matrix.dispose(closeDatabase: true);
     });
   });
 }

test/database_api_test.dart

@@ -27,7 +27,7 @@ import 'package:matrix/matrix.dart';
 import 'fake_database.dart';
 
 void main() {
-  group('HiveCollections Database Test', () {
+  group('HiveCollections Database Test', () async {
     testDatabase(
       getHiveCollectionsDatabase(null),
     );

test/device_keys_list_test.dart

@@ -249,7 +249,7 @@ void main() {
 
     test('start verification', () async {
       if (!olmEnabled) return;
-      var req = client
+      var req = await client
           .userDeviceKeys['@alice:example.com']?.deviceKeys['JLAFKJWSCS']
           ?.startVerification();
       expect(req != null, true);

test/fake_matrix_api.dart

@@ -260,6 +260,7 @@ class FakeMatrixApi extends BaseClient {
           }
         }
         // and generate a fake sync
+        // ignore: discarded_futures
         _client!.handleSync(sdk.SyncUpdate(nextBatch: ''));
       }
       return {};

test/room_archived_test.dart

@@ -50,7 +50,7 @@ void main() {
       insertList.clear();
     });
 
-    tearDown(() => client.dispose().onError((e, s) {}));
+    tearDown(() async => client.dispose().onError((e, s) {}));
 
     test('archive room not loaded', () async {
       final archiveRoom =

test/timeline_context_test.dart

@@ -38,7 +38,7 @@ void main() {
     var olmEnabled = true;
 
     final countStream = StreamController<int>.broadcast();
-    Future<int> waitForCount(int count) {
+    Future<int> waitForCount(int count) async {
       if (updateCount == count) {
         return Future.value(updateCount);
       }
@@ -46,9 +46,9 @@ void main() {
       final completer = Completer<int>();
 
       StreamSubscription<int>? sub;
-      sub = countStream.stream.listen((newCount) {
+      sub = countStream.stream.listen((newCount) async {
         if (newCount == count) {
-          sub?.cancel();
+          await sub?.cancel();
           completer.complete(count);
         }
       });
@@ -100,7 +100,8 @@ void main() {
       testTimeStamp = DateTime.now().millisecondsSinceEpoch;
     });
 
-    tearDown(() => client.dispose(closeDatabase: true).onError((e, s) {}));
+    tearDown(
+        () async => client.dispose(closeDatabase: true).onError((e, s) {}));
 
     test('Request future', () async {
       timeline.events.clear();

test/timeline_test.dart

@@ -39,7 +39,7 @@ void main() {
     var currentPoison = 0;
 
     final countStream = StreamController<int>.broadcast();
-    Future<int> waitForCount(int count) {
+    Future<int> waitForCount(int count) async {
       if (updateCount == count) {
         return Future.value(updateCount);
       }
@@ -47,9 +47,9 @@ void main() {
       final completer = Completer<int>();
 
       StreamSubscription<int>? sub;
-      sub = countStream.stream.listen((newCount) {
+      sub = countStream.stream.listen((newCount) async {
         if (newCount == count) {
-          sub?.cancel();
+          await sub?.cancel();
           completer.complete(count);
         }
       });
@@ -109,7 +109,8 @@ void main() {
       testTimeStamp = DateTime.now().millisecondsSinceEpoch;
     });
 
-    tearDown(() => client.dispose(closeDatabase: true).onError((e, s) {}));
+    tearDown(
+        () async => client.dispose(closeDatabase: true).onError((e, s) {}));
 
     test('Create', () async {
       client.onEvent.add(EventUpdate(