fix: apply review feedback

lib/encryption/key_manager.dart

@@ -990,16 +990,12 @@ class RoomKeyRequest extends ToDeviceEvent {
     final room = this.room;
     final session = await keyManager.loadInboundGroupSession(
         room.id, request.sessionId, request.senderKey);
-    if (session == null) {
-      Logs().v("[KeyManager] Not forwarding key we don't have");
-      return;
-    }
-    if (session.inboundGroupSession == null) {
+    if (session?.inboundGroupSession == null) {
       Logs().v("[KeyManager] Not forwarding key we don't have");
       return;
     }
 
-    final message = session.content.copy();
+    final message = session!.content.copy();
     message['forwarding_curve25519_key_chain'] =
         List<String>.from(session.forwardingCurve25519KeyChain);
 

lib/encryption/olm_manager.dart

@@ -50,7 +50,7 @@ class OlmManager {
   Map<String, List<OlmSession>> get olmSessions => _olmSessions;
   final Map<String, List<OlmSession>> _olmSessions = {};
 
-  // NOTE(Nico): Do we really want to create a new account on passing null instead of signing the user out?
+  // NOTE(Nico): On initial login we pass null to create a new account
   Future<void> init(String? olmAccount) async {
     if (olmAccount == null) {
       try {

lib/encryption/utils/key_verification.dart

@@ -810,7 +810,7 @@ class _KeyVerificationMethodSas extends _KeyVerificationMethod {
   }
 
   Future<void> _sendAccept() async {
-    final sas = this.sas ??= olm.SAS();
+    final sas = this.sas = olm.SAS();
     commitment = _makeCommitment(sas.get_pubkey(), startCanonicalJson);
     await request.send(EventTypes.KeyVerificationAccept, {
       'method': type,

lib/encryption/utils/session_key.dart

@@ -17,6 +17,7 @@
  */
 
 import 'package:matrix/encryption/utils/stored_inbound_group_session.dart';
+import 'package:matrix_api_lite/src/utils/filter_map_extension.dart';
 import 'package:olm/olm.dart' as olm;
 
 import '../../matrix.dart';
@@ -76,22 +77,23 @@ class SessionKey {
   SessionKey.fromDb(StoredInboundGroupSession dbEntry, String key)
       : key = key,
         content = Event.getMapFromPayload(dbEntry.content),
-        indexes =
-            Map<String, String>.from(Event.getMapFromPayload(dbEntry.indexes)),
-        allowedAtIndex = Map<String, Map<String, int>>.from(
-            Event.getMapFromPayload(dbEntry.allowedAtIndex)
-                .map((k, v) => MapEntry(k, Map<String, int>.from(v)))),
+        indexes = Event.getMapFromPayload(dbEntry.indexes)
+            .catchMap((k, v) => MapEntry(k, v as String)),
+        allowedAtIndex = Event.getMapFromPayload(dbEntry.allowedAtIndex)
+            .catchMap((k, v) => MapEntry(k, Map<String, int>.from(v))),
         roomId = dbEntry.roomId,
         sessionId = dbEntry.sessionId,
         senderKey = dbEntry.senderKey,
         inboundGroupSession = olm.InboundGroupSession() {
-    final parsedSenderClaimedKeys = Map<String, String>.from(
-        Event.getMapFromPayload(dbEntry.senderClaimedKeys));
+    final parsedSenderClaimedKeys =
+        Event.getMapFromPayload(dbEntry.senderClaimedKeys)
+            .catchMap((k, v) => MapEntry(k, v as String));
     // we need to try...catch as the map used to be <String, int> and that will throw an error.
     senderClaimedKeys = (parsedSenderClaimedKeys.isNotEmpty)
         ? parsedSenderClaimedKeys
         : (content['sender_claimed_keys'] is Map
-            ? Map<String, String>.from(content['sender_claimed_keys'])
+            ? content['sender_claimed_keys']
+                .catchMap((k, v) => MapEntry(k, v as String))
             : (content['sender_claimed_ed25519_key'] is String
                 ? <String, String>{
                     'ed25519': content['sender_claimed_ed25519_key']

lib/src/utils/device_keys_list.dart

@@ -183,7 +183,7 @@ abstract class SignableKey extends MatrixSignableKey {
     return String.fromCharCodes(canonicalJson.encode(data));
   }
 
-  bool _verifySignature(String /*!*/ pubKey, String /*!*/ signature,
+  bool _verifySignature(String pubKey, String signature,
       {bool isSignatureWithoutLibolmValid = false}) {
     olm.Utility olmutil;
     try {
@@ -321,7 +321,7 @@ abstract class SignableKey extends MatrixSignableKey {
     }
   }
 
-  Future<void> /*!*/ setBlocked(bool newBlocked);
+  Future<void> setBlocked(bool newBlocked);
 
   @override
   Map<String, dynamic> toJson() {
@@ -416,7 +416,7 @@ class DeviceKeys extends SignableKey {
       _validSelfSignature ??
       (_validSelfSignature = (deviceId != null &&
               signatures
-                      ?.tryGet<Map<String, dynamic>>(userId)
+                      ?.tryGetMap<String, dynamic>(userId)
                       ?.tryGet<String>('ed25519:$deviceId') ==
                   null
           ? false