when<TResult extends Object?> method

@optionalTypeArgs TResult when<TResult extends Object?>(TResult $default(String? authority, String? serviceName, bool? multiMode, @JsonKey.new(name: 'idle_timeout') int? idleTimeout, @JsonKey.new(name: 'health_check_timeout') int? healthCheckTimeout, @JsonKey.new(name: 'permit_without_stream') bool? permitWithoutStream, @JsonKey.new(name: 'initial_windows_size') int? initialWindowsSize, @JsonKey.new(name: 'user_agent') String? userAgent,))

A switch-like method, using callbacks.

As opposed to map, this offers destructuring. It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case Subclass2(:final field2):
    return ...;
}

Implementation

@optionalTypeArgs
TResult when<TResult extends Object?>(
  TResult Function(
          String? authority,
          String? serviceName,
          bool? multiMode,
          @JsonKey(name: 'idle_timeout') int? idleTimeout,
          @JsonKey(name: 'health_check_timeout') int? healthCheckTimeout,
          @JsonKey(name: 'permit_without_stream') bool? permitWithoutStream,
          @JsonKey(name: 'initial_windows_size') int? initialWindowsSize,
          @JsonKey(name: 'user_agent') String? userAgent)
      $default,
) {
  final _that = this;
  switch (_that) {
    case _GRPCConfig():
      return $default(
          _that.authority,
          _that.serviceName,
          _that.multiMode,
          _that.idleTimeout,
          _that.healthCheckTimeout,
          _that.permitWithoutStream,
          _that.initialWindowsSize,
          _that.userAgent);
    case _:
      throw StateError('Unexpected subclass');
  }
}