whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>(
  1. TResult? $default(
    1. bool status,
    2. String? message,
    3. List<IsibookReservationExtra> extras
    )?
)

A variant of when that fallback to returning null

It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case _:
    return null;
}

Implementation

@optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>(
  TResult? Function(
          bool status, String? message, List<IsibookReservationExtra> extras)?
      $default,
) {
  final _that = this;
  switch (_that) {
    case _IsibookExtrasResponse() when $default != null:
      return $default(_that.status, _that.message, _that.extras);
    case _:
      return null;
  }
}