fix: Review changes

packages/stream_chat/lib/src/db/chat_persistence_client.dart

@@ -39,32 +39,32 @@ abstract class ChatPersistenceClient {
   Future<List<String>> getChannelCids();
 
   /// Get stored [ChannelModel]s by providing channel [cid]
-  Future<ChannelModel> getChannelByCid(String? cid);
+  Future<ChannelModel> getChannelByCid(String cid);
 
   /// Get stored channel [Member]s by providing channel [cid]
-  Future<List<Member>> getMembersByCid(String? cid);
+  Future<List<Member>> getMembersByCid(String cid);
 
   /// Get stored channel [Read]s by providing channel [cid]
-  Future<List<Read>> getReadsByCid(String? cid);
+  Future<List<Read>> getReadsByCid(String cid);
 
   /// Get stored [Message]s by providing channel [cid]
   ///
   /// Optionally, you can [messagePagination]
   /// for filtering out messages
   Future<List<Message>> getMessagesByCid(
-    String? cid, {
+    String cid, {
     PaginationParams? messagePagination,
   });
 
   /// Get stored pinned [Message]s by providing channel [cid]
   Future<List<Message>> getPinnedMessagesByCid(
-    String? cid, {
+    String cid, {
     PaginationParams? messagePagination,
   });
 
   /// Get [ChannelState] data by providing channel [cid]
   Future<ChannelState> getChannelStateByCid(
-    String? cid, {
+    String cid, {
     PaginationParams? messagePagination,
     PaginationParams? pinnedMessagePagination,
   }) async {
@@ -99,8 +99,8 @@ abstract class ChatPersistenceClient {
   /// If [clearQueryCache] is true before the insert
   /// the list of matching rows will be deleted
   Future<void> updateChannelQueries(
-    Map<String, dynamic>? filter,
-    List<String?> cids, {
+    Map<String, dynamic> filter,
+    List<String> cids, {
     bool clearQueryCache = false,
   });
 
@@ -119,46 +119,46 @@ abstract class ChatPersistenceClient {
   Future<void> deletePinnedMessageByIds(List<String> messageIds);
 
   /// Remove a message by channel [cid]
-  Future<void> deleteMessageByCid(String? cid) => deleteMessageByCids([cid]);
+  Future<void> deleteMessageByCid(String cid) => deleteMessageByCids([cid]);
 
   /// Remove a pinned message by channel [cid]
   Future<void> deletePinnedMessageByCid(String cid) async =>
       deletePinnedMessageByCids([cid]);
 
   /// Remove a message by message [cids]
-  Future<void> deleteMessageByCids(List<String?> cids);
+  Future<void> deleteMessageByCids(List<String> cids);
 
   /// Remove a pinned message by message [cids]
   Future<void> deletePinnedMessageByCids(List<String> cids);
 
   /// Remove a channel by [cid]
-  Future<void> deleteChannels(List<String?> cids);
+  Future<void> deleteChannels(List<String> cids);
 
   /// Updates the message data of a particular channel [cid] with
   /// the new [messages] data
-  Future<void> updateMessages(String? cid, List<Message> messages);
+  Future<void> updateMessages(String cid, List<Message> messages);
 
   /// Updates the pinned message data of a particular channel [cid] with
   /// the new [messages] data
-  Future<void> updatePinnedMessages(String? cid, List<Message> messages);
+  Future<void> updatePinnedMessages(String cid, List<Message> messages);
 
   /// Returns all the threads by parent message of a particular channel by
   /// providing channel [cid]
-  Future<Map<String, List<Message>>> getChannelThreads(String? cid);
+  Future<Map<String, List<Message>>> getChannelThreads(String cid);
 
   /// Updates all the channels using the new [channels] data.
-  Future<void> updateChannels(List<ChannelModel?> channels);
+  Future<void> updateChannels(List<ChannelModel> channels);
 
   /// Updates all the members of a particular channle [cid]
   /// with the new [members] data
-  Future<void> updateMembers(String? cid, List<Member?> members);
+  Future<void> updateMembers(String cid, List<Member> members);
 
   /// Updates the read data of a particular channel [cid] with
   /// the new [reads] data
-  Future<void> updateReads(String? cid, List<Read> reads);
+  Future<void> updateReads(String cid, List<Read> reads);
 
   /// Updates the users data with the new [users] data
-  Future<void> updateUsers(List<User?> users);
+  Future<void> updateUsers(List<User> users);
 
   /// Updates the reactions data with the new [reactions] data
   Future<void> updateReactions(List<Reaction> reactions);
@@ -167,7 +167,7 @@ abstract class ChatPersistenceClient {
   Future<void> deleteReactionsByMessageId(List<String> messageIds);
 
   /// Deletes all the members by channel [cids]
-  Future<void> deleteMembersByCids(List<String?> cids);
+  Future<void> deleteMembersByCids(List<String> cids);
 
   /// Update the channel state data using [channelState]
   Future<void> updateChannelState(ChannelState channelState) =>
@@ -189,8 +189,9 @@ abstract class ChatPersistenceClient {
       deleteMembers,
     ]);
 
-    final channels =
-        channelStates.map((it) => it.channel).where((it) => it != null);
+    final channels = channelStates
+        .map((it) => it.channel)
+        .where((it) => it != null) as Iterable<ChannelModel>;
 
     final reactions = channelStates.expand((it) => it.messages).expand((it) => [
           if (it.ownReactions != null)
@@ -199,7 +200,7 @@ abstract class ChatPersistenceClient {
             ...it.latestReactions!.where((r) => r.userId != null)
         ]);
 
-    final users = channelStates
+    var users = channelStates
         .map((cs) => [
               cs.channel?.createdBy,
               ...cs.messages
@@ -215,7 +216,7 @@ abstract class ChatPersistenceClient {
               ...cs.members.map((m) => m.user),
             ])
         .expand((it) => it)
-        .where((it) => it != null);
+        .where((it) => it != null) as Iterable<User>;
 
     final updateMessagesFuture = channelStates.map((it) {
       final cid = it.channel!.cid;