Refactor state_controller.dart: Ignore error and stack trace in setState method

Author: PlugFox

lib/src/state_controller.dart

@@ -43,7 +43,7 @@ abstract base class StateController<S extends Object> extends Controller
   void setState(S state) {
     runZonedGuarded<void>(
       () => Controller.observer?.onStateChanged(this, _$state, state),
-      (error, stackTrace) {/* ignore */},
+      (error, stackTrace) {/* ignore */}, // coverage:ignore-line
     );
     _$state = state;
     if (isDisposed) return;

test/unit/handler_context_test.dart

@@ -29,6 +29,7 @@ void main() => group('HandlerContext', () {
           expect(lastContext, isNotNull);
           await expectLater(lastContext!.done, completes);
           // Event should be done by now.
+          expect(lastContext!.isDone, isTrue);
           expect(
             lastContext,
             allOf(