diff --git a/lib/models/conversation_message.dart b/lib/models/conversation_message.dart
index 76e3cc8..4a8cfc4 100644
--- a/lib/models/conversation_message.dart
+++ b/lib/models/conversation_message.dart
@@ -199,11 +199,8 @@ class ConversationMessage extends SerializableElement<ConversationMessage> {
     required this.message,
     required this.file,
     required this.serverMessage,
-  })  : assert(id != null),
-        assert(convID != null),
-        assert(userID != null || serverMessage != null),
-        assert(timeSent != null),
-        assert(message != null || file != null || serverMessage != null);
+  })  : assert(userID != null || serverMessage != null),
+        assert(!message.isNull || file != null || serverMessage != null);
 
   DateTime get date => DateTime.fromMillisecondsSinceEpoch(timeSent! * 1000);
 
diff --git a/lib/models/count_unread_notifications.dart b/lib/models/count_unread_notifications.dart
index a7e7968..1cf9bf3 100644
--- a/lib/models/count_unread_notifications.dart
+++ b/lib/models/count_unread_notifications.dart
@@ -9,6 +9,5 @@ class CountUnreadNotifications {
   CountUnreadNotifications({
     required int this.notifications,
     required int this.conversations,
-  })  : assert(notifications != null),
-        assert(conversations != null);
+  });
 }
diff --git a/lib/ui/widgets/group_membership_widget.dart b/lib/ui/widgets/group_membership_widget.dart
index 58c8ad6..b72fe40 100644
--- a/lib/ui/widgets/group_membership_widget.dart
+++ b/lib/ui/widgets/group_membership_widget.dart
@@ -16,8 +16,7 @@ class GroupMembershipWidget extends StatefulWidget {
   final Function()? onError;
 
   const GroupMembershipWidget(
-      {required this.group, this.onUpdated, this.onError})
-      : assert(group != null);
+      {required this.group, this.onUpdated, this.onError});
 
   @override
   _GroupMembershipWidgetState createState() => _GroupMembershipWidgetState();
@@ -120,7 +119,8 @@ class _GroupMembershipWidgetState extends SafeState<GroupMembershipWidget> {
   /// Cancel group membership request
   void _cancelRequest() async {
     if (!await GroupsHelper().cancelRequest(_id)) {
-      showSimpleSnack(context, tr("Could not cancel your membership request!")!);
+      showSimpleSnack(
+          context, tr("Could not cancel your membership request!")!);
       if (this.widget.onError != null) this.widget.onError!();
     } else {
       // Refresh state
diff --git a/lib/ui/widgets/icon_button_badge.dart b/lib/ui/widgets/icon_button_badge.dart
index 76888d8..fe336e6 100644
--- a/lib/ui/widgets/icon_button_badge.dart
+++ b/lib/ui/widgets/icon_button_badge.dart
@@ -18,10 +18,7 @@ class IconButtonWithBadge extends StatelessWidget {
     required this.onPressed,
     this.number = 0,
     this.active = false,
-  })  : assert(icon != null),
-        assert(number != null),
-        assert(active != null),
-        super(key: key);
+  }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
diff --git a/lib/ui/widgets/mobile_mode/mobile_appbar_widget.dart b/lib/ui/widgets/mobile_mode/mobile_appbar_widget.dart
index ae8566f..4940b73 100644
--- a/lib/ui/widgets/mobile_mode/mobile_appbar_widget.dart
+++ b/lib/ui/widgets/mobile_mode/mobile_appbar_widget.dart
@@ -45,10 +45,7 @@ class _MenuItem {
     required this.action,
     required this.pageType,
     this.isMenu = false,
-  })  : assert(label != null),
-        assert(isMenu != null),
-        assert(isMenu || icon != null),
-        assert(isMenu || action != null),
+  })  : assert(isMenu || action != null),
         assert(isMenu || pageType != null);
 }
 
@@ -57,9 +54,7 @@ class _ActionMenuItem {
   final String label;
   final BarCallbackActions action;
 
-  const _ActionMenuItem({required this.label, required this.action})
-      : assert(label != null),
-        assert(action != null);
+  const _ActionMenuItem({required this.label, required this.action});
 }
 
 /// List of menu items to show
@@ -113,8 +108,7 @@ class ComunicMobileAppBar extends StatefulWidget
   const ComunicMobileAppBar({
     Key? key,
     required this.currentPage,
-  })  : assert(currentPage != null),
-        super(key: key);
+  }) : super(key: key);
 
   @override
   _ComunicMobileAppBarState createState() => _ComunicMobileAppBarState();
@@ -154,8 +148,6 @@ class _ComunicMobileAppBarState extends SafeState<ComunicMobileAppBar> {
 
   /// Get the number of unread notifications for the selected notice
   int? getNumberUnread(BarCallbackActions? action) {
-    if (_unreadNotifications == null) return 0;
-
     switch (action) {
       case BarCallbackActions.OPEN_NOTIFICATIONS:
         return _unreadNotifications.notifications;
diff --git a/lib/ui/widgets/mobile_mode/user_page_mobile.dart b/lib/ui/widgets/mobile_mode/user_page_mobile.dart
index 0586c5a..e1a478c 100644
--- a/lib/ui/widgets/mobile_mode/user_page_mobile.dart
+++ b/lib/ui/widgets/mobile_mode/user_page_mobile.dart
@@ -19,9 +19,7 @@ class UserMobilePage extends StatefulWidget {
     Key? key,
     required this.userInfo,
     required this.onNeedRefresh,
-  })  : assert(userInfo != null),
-        assert(onNeedRefresh != null),
-        super(key: key);
+  }) : super(key: key);
 
   @override
   _UserMobilePageState createState() => _UserMobilePageState();
@@ -114,9 +112,7 @@ class UserPageTab {
     required this.label,
     required this.onBuild,
     this.visible = true,
-  })  : assert(label != null),
-        assert(onBuild != null),
-        assert(visible != null);
+  });
 
   Tab get tab => Tab(text: label);
 }
diff --git a/lib/ui/widgets/network_image_widget.dart b/lib/ui/widgets/network_image_widget.dart
index f35d070..b240c28 100644
--- a/lib/ui/widgets/network_image_widget.dart
+++ b/lib/ui/widgets/network_image_widget.dart
@@ -26,9 +26,7 @@ class NetworkImageWidget extends StatelessWidget {
     this.height,
     this.roundedEdges = true,
     this.loadingHeight,
-  })  : assert(url != null),
-        assert(allowFullScreen != null),
-        super(key: key);
+  })  : super(key: key);
 
   double? get _loadingHeight => loadingHeight != null ? loadingHeight : height;
 
diff --git a/lib/ui/widgets/new_password_input_widget.dart b/lib/ui/widgets/new_password_input_widget.dart
index 5ea8e0c..e7569c9 100644
--- a/lib/ui/widgets/new_password_input_widget.dart
+++ b/lib/ui/widgets/new_password_input_widget.dart
@@ -36,9 +36,7 @@ class NewPasswordInputWidget extends StatefulWidget {
     this.textInputAction,
     required this.label,
     required this.user,
-  })  : assert(label != null),
-        assert(user != null),
-        super(key: key);
+  })  : super(key: key);
 
   @override
   NewPasswordInputWidgetState createState() => NewPasswordInputWidgetState();
diff --git a/lib/ui/widgets/pick_user_widget.dart b/lib/ui/widgets/pick_user_widget.dart
index 786b981..c7ae9ca 100644
--- a/lib/ui/widgets/pick_user_widget.dart
+++ b/lib/ui/widgets/pick_user_widget.dart
@@ -29,11 +29,7 @@ class PickUserWidget extends StatefulWidget {
     this.keepFocusOnChoose = false,
     this.onValueChange,
     this.enabled = true,
-  })  : assert(onSelectUser != null),
-        assert(label != null),
-        assert(resetOnChoose != null),
-        assert(keepFocusOnChoose != null),
-        super(key: key);
+  }) : super(key: key);
 
   @override
   State<StatefulWidget> createState() => _PickUserWidgetState();
diff --git a/lib/ui/widgets/post_create_form_widget.dart b/lib/ui/widgets/post_create_form_widget.dart
index d76b000..ae418e3 100644
--- a/lib/ui/widgets/post_create_form_widget.dart
+++ b/lib/ui/widgets/post_create_form_widget.dart
@@ -35,9 +35,7 @@ class PostCreateFormWidget extends StatefulWidget {
     required this.postTarget,
     required this.targetID,
     required this.onCreated,
-  })  : assert(postTarget != null),
-        assert(targetID != null),
-        super(key: key);
+  }) : super(key: key);
 
   @override
   _PostCreateFormWidgetState createState() => _PostCreateFormWidgetState();
@@ -403,10 +401,7 @@ class _PostOptionWidget extends StatelessWidget {
       required this.selected,
       required this.onTap,
       this.customColor})
-      : assert(icon != null),
-        assert(selected != null),
-        assert(onTap != null),
-        super(key: key);
+      : super(key: key);
 
   bool get hasCustomColor => customColor != null;
 
diff --git a/lib/ui/widgets/settings/text_settings_edit_tile.dart b/lib/ui/widgets/settings/text_settings_edit_tile.dart
index a4c5486..33ef821 100644
--- a/lib/ui/widgets/settings/text_settings_edit_tile.dart
+++ b/lib/ui/widgets/settings/text_settings_edit_tile.dart
@@ -14,7 +14,7 @@ bool _defaultCheck(String s) => s.isNotEmpty;
 class TextEditSettingsTile extends SettingsTile {
   final String title;
   final String currValue;
-  final void Function(String) onChanged;
+  final void Function(String)? onChanged;
   final bool Function(String) checkInput;
   final bool allowEmptyValues;
   final int maxLines;
@@ -31,11 +31,7 @@ class TextEditSettingsTile extends SettingsTile {
     this.allowEmptyValues = false,
     this.maxLength,
     this.maxLines = 1,
-  })  : assert(title != null),
-        assert(currValue != null),
-        assert(checkInput != null),
-        assert(allowEmptyValues != null),
-        assert(maxLines != null);
+  });
 
   @override
   Widget build(BuildContext context) {
@@ -64,6 +60,6 @@ class TextEditSettingsTile extends SettingsTile {
 
     if (value == null) return;
 
-    onChanged(value);
+    onChanged!(value);
   }
 }
diff --git a/lib/ui/widgets/survey_widget.dart b/lib/ui/widgets/survey_widget.dart
index ba1cb7a..8293126 100644
--- a/lib/ui/widgets/survey_widget.dart
+++ b/lib/ui/widgets/survey_widget.dart
@@ -19,9 +19,7 @@ class SurveyWidget extends StatefulWidget {
     Key? key,
     required this.survey,
     required this.onUpdated,
-  })  : assert(survey != null),
-        assert(onUpdated != null),
-        super(key: key);
+  }) : super(key: key);
 
   @override
   _SurveyWidgetState createState() => _SurveyWidgetState();
@@ -202,7 +200,8 @@ class _SurveyWidgetState extends SafeState<SurveyWidget> {
     try {
       if (!await showConfirmDialog(
           context: context,
-          message: tr("Do you really want to block new choices creation?"))) return;
+          message: tr("Do you really want to block new choices creation?")))
+        return;
 
       await SurveyHelper.blockNewChoicesCreation(survey.postID);
 
diff --git a/lib/ui/widgets/tab_transition_widget.dart b/lib/ui/widgets/tab_transition_widget.dart
index 14e95b6..90c2440 100644
--- a/lib/ui/widgets/tab_transition_widget.dart
+++ b/lib/ui/widgets/tab_transition_widget.dart
@@ -4,8 +4,7 @@ class TabTransitionWidget extends StatefulWidget {
   final Widget child;
 
   const TabTransitionWidget(this.child, {Key? key})
-      : assert(child != null),
-        super(key: key);
+      : super(key: key);
 
   @override
   _TabTransitionWidgetState createState() => _TabTransitionWidgetState();
diff --git a/lib/ui/widgets/tablet_mode/appbar_custom_dropdown_widget.dart b/lib/ui/widgets/tablet_mode/appbar_custom_dropdown_widget.dart
index 7b086df..b902dce 100644
--- a/lib/ui/widgets/tablet_mode/appbar_custom_dropdown_widget.dart
+++ b/lib/ui/widgets/tablet_mode/appbar_custom_dropdown_widget.dart
@@ -18,10 +18,7 @@ class AppBarCustomDropDownWidget extends StatefulWidget {
     required this.icon,
     required this.notificationsBadge,
     required this.onBuildOverlay,
-  })  : assert(icon != null),
-        assert(notificationsBadge != null),
-        assert(onBuildOverlay != null),
-        super(key: key);
+  }) : super(key: key);
 
   @override
   AppBarCustomDropDownWidgetState createState() =>
diff --git a/lib/ui/widgets/tablet_mode/calls/call_window_widget.dart b/lib/ui/widgets/tablet_mode/calls/call_window_widget.dart
index a2e1531..a2ea4ec 100644
--- a/lib/ui/widgets/tablet_mode/calls/call_window_widget.dart
+++ b/lib/ui/widgets/tablet_mode/calls/call_window_widget.dart
@@ -18,9 +18,7 @@ class CallWindowWidget extends StatefulWidget {
     Key? key,
     required this.convID,
     required this.onClose,
-  })  : assert(convID != null),
-        assert(onClose != null),
-        super(key: key);
+  }) : super(key: key);
 
   @override
   _CallWindowWidgetState createState() => _CallWindowWidgetState();
diff --git a/lib/ui/widgets/tablet_mode/conversations/conversation_window.dart b/lib/ui/widgets/tablet_mode/conversations/conversation_window.dart
index ec0a48a..94e1af3 100644
--- a/lib/ui/widgets/tablet_mode/conversations/conversation_window.dart
+++ b/lib/ui/widgets/tablet_mode/conversations/conversation_window.dart
@@ -27,9 +27,7 @@ class ConversationWindow extends StatefulWidget {
     Key? key,
     required this.convID,
     required this.onClose,
-  })  : assert(convID != null),
-        assert(onClose != null),
-        super(key: key);
+  }) : super(key: key);
 
   @override
   _ConversationWindowState createState() => _ConversationWindowState();
@@ -59,10 +57,8 @@ class _ConversationWindowState extends SafeState<ConversationWindow> {
 
       final conversation =
           await ConversationsHelper().getSingle(_convID, force: true);
-      assert(conversation != null);
       final name =
           await ConversationsHelper.getConversationNameAsync(conversation);
-      assert(name != null);
 
       setState(() {
         _conversation = conversation;
diff --git a/lib/ui/widgets/tablet_mode/conversations/conversation_window_container.dart b/lib/ui/widgets/tablet_mode/conversations/conversation_window_container.dart
index 4e662b7..a2c02ea 100644
--- a/lib/ui/widgets/tablet_mode/conversations/conversation_window_container.dart
+++ b/lib/ui/widgets/tablet_mode/conversations/conversation_window_container.dart
@@ -27,12 +27,7 @@ class ConversationWindowContainer extends StatelessWidget {
     required this.onToggleCollapse,
     required this.isCollapsed,
     this.action,
-  })  : assert(title != null),
-        assert(onClose != null),
-        assert(body != null),
-        assert(onToggleCollapse != null),
-        assert(isCollapsed != null),
-        super(key: key);
+  }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
diff --git a/lib/ui/widgets/tablet_mode/global_search_field.dart b/lib/ui/widgets/tablet_mode/global_search_field.dart
index 220afe9..7fb86c9 100644
--- a/lib/ui/widgets/tablet_mode/global_search_field.dart
+++ b/lib/ui/widgets/tablet_mode/global_search_field.dart
@@ -147,8 +147,7 @@ class _SearchResultsWidget extends StatelessWidget {
     Key? key,
     required this.results,
     required this.onTap,
-  })  : assert(onTap != null),
-        super(key: key);
+  })  : super(key: key);
 
   @override
   Widget build(BuildContext context) {
diff --git a/lib/ui/widgets/tablet_mode/memberships_panel.dart b/lib/ui/widgets/tablet_mode/memberships_panel.dart
index 95194a5..617698a 100644
--- a/lib/ui/widgets/tablet_mode/memberships_panel.dart
+++ b/lib/ui/widgets/tablet_mode/memberships_panel.dart
@@ -31,8 +31,7 @@ class MembershipsPanel extends StatefulWidget {
   const MembershipsPanel({
     Key? key,
     required this.currentPage,
-  })  : assert(currentPage != null),
-        super(key: key);
+  })  : super(key: key);
 
   @override
   _MembershipsPanelState createState() => _MembershipsPanelState();
diff --git a/lib/ui/widgets/tablet_mode/tablet_appbar_widget.dart b/lib/ui/widgets/tablet_mode/tablet_appbar_widget.dart
index a689352..389329e 100644
--- a/lib/ui/widgets/tablet_mode/tablet_appbar_widget.dart
+++ b/lib/ui/widgets/tablet_mode/tablet_appbar_widget.dart
@@ -139,9 +139,7 @@ class _MainMenuItem extends PopupMenuEntry<_MenuItemCallback> {
     required this.label,
     required this.icon,
     required this.onTap,
-  })  : assert(label != null),
-        assert(icon != null),
-        assert(onTap != null);
+  });
 
   @override
   __MainMenuItemState createState() => __MainMenuItemState();
diff --git a/lib/ui/widgets/tablet_mode/user_page_tablet.dart b/lib/ui/widgets/tablet_mode/user_page_tablet.dart
index cdcc30c..dad5472 100644
--- a/lib/ui/widgets/tablet_mode/user_page_tablet.dart
+++ b/lib/ui/widgets/tablet_mode/user_page_tablet.dart
@@ -31,9 +31,7 @@ class UserPageTablet extends StatefulWidget {
     required this.userInfo,
     required this.friendshipStatus,
     required this.onNeedRefresh,
-  })  : assert(userInfo != null),
-        assert(onNeedRefresh != null),
-        super(key: key);
+  }) : super(key: key);
 
   @override
   _UserPageTabletState createState() => _UserPageTabletState();
diff --git a/lib/ui/widgets/text_widget.dart b/lib/ui/widgets/text_widget.dart
index f489eeb..e2d7d05 100644
--- a/lib/ui/widgets/text_widget.dart
+++ b/lib/ui/widgets/text_widget.dart
@@ -24,10 +24,7 @@ class TextWidget extends StatelessWidget {
     this.textAlign = TextAlign.start,
     this.style,
     this.linksColor = Colors.blueAccent,
-  })  : assert(content != null),
-        assert(parseBBcode != null),
-        assert(linksColor != null),
-        super(key: key);
+  })  : super(key: key);
 
   @override
   Widget build(BuildContext context) {
diff --git a/lib/ui/widgets/tour/tour_notifications_pane.dart b/lib/ui/widgets/tour/tour_notifications_pane.dart
index 0bf63ec..615cb86 100644
--- a/lib/ui/widgets/tour/tour_notifications_pane.dart
+++ b/lib/ui/widgets/tour/tour_notifications_pane.dart
@@ -18,8 +18,7 @@ class TourNotificationsPane extends PresentationPane {
     required Function() onConfigured,
     required Function() onChanged,
     required bool visible,
-  })  : assert(pushNotificationsKey != null),
-        super(
+  })  : super(
           icon: Icons.notifications,
           title: tr("Push notifications")!,
           child: (c) => PushNotificationsConfigurationWidget(
diff --git a/lib/utils/bbcode_parser.dart b/lib/utils/bbcode_parser.dart
index 1567ff1..2b4372e 100644
--- a/lib/utils/bbcode_parser.dart
+++ b/lib/utils/bbcode_parser.dart
@@ -13,8 +13,7 @@ class BBCodeParsedWidget extends StatelessWidget {
   final ParseCallBack? parseCallback;
 
   BBCodeParsedWidget({required String text, this.parseCallback})
-      : assert(text != null),
-        _content = _parse(text);
+      : _content = _parse(text);
 
   _printRecur(_Element el, {int pos = 0}) {
     String str;
@@ -239,7 +238,7 @@ class _Element {
     if (parseCallback != null && text != null) {
       final parsed = parseCallback(generatedStyle, text);
 
-      if (parsed != null && parsed.length > 0)
+      if (parsed.length > 0)
         return TextSpan(
           style: generatedStyle,
           children: parsed,
diff --git a/lib/utils/navigation_utils.dart b/lib/utils/navigation_utils.dart
index 2babc41..e05563d 100644
--- a/lib/utils/navigation_utils.dart
+++ b/lib/utils/navigation_utils.dart
@@ -16,9 +16,6 @@ void popPage(BuildContext context) {
 
 /// Open the page of a user
 void openUserPage({required int userID, required BuildContext context}) {
-  assert(userID != null);
-  assert(context != null);
-
   MainController.of(context)!.openUserPage(userID);
 }
 
diff --git a/lib/utils/ui_utils.dart b/lib/utils/ui_utils.dart
index 1f081bd..9392a94 100644
--- a/lib/utils/ui_utils.dart
+++ b/lib/utils/ui_utils.dart
@@ -101,13 +101,6 @@ Future<String?> askUserString({
   int maxLength = 200,
   int minLength = 1,
 }) async {
-  assert(context != null);
-  assert(title != null);
-  assert(message != null);
-  assert(defaultValue != null);
-  assert(hint != null);
-  assert(maxLength != null);
-
   TextEditingController controller = TextEditingController(text: defaultValue);
 
   final confirm = await showDialog<bool>(
@@ -257,7 +250,8 @@ const darkAccentColor = Colors.white70;
 const darkerAccentColor = Colors.white30;
 
 /// Check out whether dark theme is enabled or not
-bool darkTheme() => preferences()!.getBool(PreferencesKeyList.ENABLE_DARK_THEME);
+bool darkTheme() =>
+    preferences()!.getBool(PreferencesKeyList.ENABLE_DARK_THEME);
 
 /// Check out whether we use tablet mode or not
 bool isTablet(BuildContext context) =>