Dart Sealed Classes Guide — Type-Safe State Management with Pattern Matching

Dart Sealed Classes Guide — Type-Safe State Management with Pattern Matching Dart 3's sealed classes are the evolution of enums. They restrict subtyping to a closed set and enforce exhaustive switch coverage. The result: fewer runtime errors, richer domain models, cleaner state machines. Basic Sealed Class sealed class AuthState {} class AuthInitial extends AuthState {} class AuthLoading extends AuthState {} class AuthSuccess extends AuthState { final String userId ; final String email ; AuthSuc