refactor: make onError StackTrace non-nullable

packages/bloc/example/main.dart

@@ -22,7 +22,7 @@ class SimpleBlocObserver extends BlocObserver {
   }
 
   @override
-  void onError(Cubit cubit, Object error, StackTrace? stackTrace) {
+  void onError(Cubit cubit, Object error, StackTrace stackTrace) {
     print('cubit: ${cubit.runtimeType}, error: $error');
     super.onError(cubit, error, stackTrace);
   }

packages/bloc/lib/src/bloc.dart

@@ -25,9 +25,9 @@ abstract class Bloc<Event, State> extends Cubit<State>
   /// The current [BlocObserver].
   static BlocObserver observer = BlocObserver();
 
-  late final _eventController = StreamController<Event>.broadcast();
+  final _eventController = StreamController<Event>.broadcast();
 
-  StreamSubscription<Transition<Event, State>>? _transitionSubscription;
+  late StreamSubscription<Transition<Event, State>> _transitionSubscription;
 
   bool _emitted = false;
 
@@ -169,14 +169,12 @@ abstract class Bloc<Event, State> extends Cubit<State>
   /// Notifies the [Bloc] of an [error] which triggers [onError].
   @override
   void addError(Object error, [StackTrace? stackTrace]) {
-    onError(error, stackTrace);
+    onError(error, stackTrace ?? StackTrace.current);
   }
 
   /// Called whenever an [error] is thrown within [mapEventToState].
   /// By default all [error]s will be ignored and [Bloc] functionality will be
   /// unaffected.
-  /// The [stackTrace] argument may be `null` if the [state] stream received
-  /// an error without a [stackTrace].
   /// A great spot to handle errors at the individual [Bloc] level.
   ///
   /// **Note: `super.onError` should always be called last.**
@@ -197,7 +195,7 @@ abstract class Bloc<Event, State> extends Cubit<State>
   @protected
   @mustCallSuper
   @override
-  void onError(Object error, StackTrace? stackTrace) {
+  void onError(Object error, StackTrace stackTrace) {
     super.onError(error, stackTrace);
   }
 
@@ -211,7 +209,7 @@ abstract class Bloc<Event, State> extends Cubit<State>
   @mustCallSuper
   Future<void> close() async {
     await _eventController.close();
-    await _transitionSubscription?.cancel();
+    await _transitionSubscription.cancel();
     return super.close();
   }
 

packages/bloc/lib/src/bloc_observer.dart

@@ -34,5 +34,5 @@ class BlocObserver {
   /// an error without a [stackTrace].
   @protected
   @mustCallSuper
-  void onError(Cubit cubit, Object error, StackTrace? stackTrace) {}
+  void onError(Cubit cubit, Object error, StackTrace stackTrace) {}
 }

packages/bloc/lib/src/cubit.dart

@@ -86,7 +86,7 @@ abstract class Cubit<State> extends Stream<State> {
 
   /// Notifies the [Cubit] of an [error] which triggers [onError].
   void addError(Object error, [StackTrace? stackTrace]) {
-    onError(error, stackTrace);
+    onError(error, stackTrace ?? StackTrace.current);
   }
 
   /// Called whenever a [change] occurs with the given [change].
@@ -117,8 +117,6 @@ abstract class Cubit<State> extends Stream<State> {
   /// Called whenever an [error] occurs within a [Cubit].
   /// By default all [error]s will be ignored and [Cubit] functionality will be
   /// unaffected.
-  /// The [stackTrace] argument may be `null` if the [state] stream received
-  /// an error without a [stackTrace].
   /// A great spot to handle errors at the individual [Cubit] level.
   ///
   /// **Note: `super.onError` should always be called last.**
@@ -133,7 +131,7 @@ abstract class Cubit<State> extends Stream<State> {
   /// ```
   @protected
   @mustCallSuper
-  void onError(Object error, StackTrace? stackTrace) {
+  void onError(Object error, StackTrace stackTrace) {
     // ignore: invalid_use_of_protected_member
     _observer.onError(this, error, stackTrace);
     assert(() {

packages/bloc/pubspec.yaml

@@ -1,6 +1,6 @@
 name: bloc
 description: A predictable state management library that helps implement the BLoC (Business Logic Component) design pattern.
-version: 6.1.0-nullsafety
+version: 7.0.0-nullsafety
 repository: https://github.com/felangel/bloc/tree/master/packages/bloc
 issue_tracker: https://github.com/felangel/bloc/issues
 homepage: https://github.com/felangel/bloc
@@ -10,16 +10,16 @@ documentation: https://bloclibrary.dev
 publish_to: none
 
 environment:
-  sdk: ">=2.10.0-99.0.dev <2.10.0"
+  sdk: ">=2.10.0-99.0.dev <2.11.0"
 
 dependencies:
   meta: ^1.3.0-nullsafety.2
 
 dev_dependencies:
+  coverage: ^0.14.1
   pedantic: ^1.9.0
   rxdart:
     git:
       url: https://github.com/ReactiveX/rxdart
       ref: nnbd
-  test_coverage: ^0.4.1
   test: ^1.16.0-nullsafety.2

packages/bloc/test/blocs/counter/counter_bloc.dart

@@ -44,7 +44,7 @@ class CounterBloc extends Bloc<CounterEvent, int> {
   }
 
   @override
-  void onError(Object error, StackTrace? stackTrace) {
+  void onError(Object error, StackTrace stackTrace) {
     onErrorCallback?.call(error, stackTrace);
     super.onError(error, stackTrace);
   }

packages/bloc/test/blocs/counter/on_error_bloc.dart

@@ -11,7 +11,7 @@ class OnErrorBloc extends Bloc<CounterEvent, int> {
   final Error error;
 
   @override
-  void onError(Object error, StackTrace? stackTrace) {
+  void onError(Object error, StackTrace stackTrace) {
     onErrorCallback(error, stackTrace);
     super.onError(error, stackTrace);
   }

packages/bloc/test/blocs/counter/on_exception_bloc.dart

@@ -14,7 +14,7 @@ class OnExceptionBloc extends Bloc<CounterEvent, int> {
   final Exception exception;
 
   @override
-  void onError(Object error, StackTrace? stackTrace) {
+  void onError(Object error, StackTrace stackTrace) {
     onErrorCallback(error, stackTrace);
     super.onError(error, stackTrace);
   }

packages/bloc/test/blocs/counter/on_transition_error_bloc.dart

@@ -14,7 +14,7 @@ class OnTransitionErrorBloc extends Bloc<CounterEvent, int> {
   final Error error;
 
   @override
-  void onError(Object error, StackTrace? stackTrace) {
+  void onError(Object error, StackTrace stackTrace) {
     onErrorCallback(error, stackTrace);
     super.onError(error, stackTrace);
   }

packages/bloc/test/main.dart

@@ -0,0 +1,13 @@
+import 'bloc_observer_test.dart' as bloc_observer_test;
+import 'bloc_test.dart' as bloc_test;
+import 'change_test.dart' as change_test;
+import 'cubit_test.dart' as cubit_test;
+import 'transition_test.dart' as transition_test;
+
+void main() {
+  bloc_test.main();
+  bloc_observer_test.main();
+  change_test.main();
+  transition_test.main();
+  cubit_test.main();
+}