whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>(
  1. TResult? $default(
    1. String id,
    2. String label,
    3. bool selected,
    4. PPAmount? amount,
    5. PPShippingMethodType? type,
    )?
)

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(String id, String label, bool selected, PPAmount? amount,
          PPShippingMethodType? type)?
      $default,
) {
  final _that = this;
  switch (_that) {
    case _PPShippingMethods() when $default != null:
      return $default(
          _that.id, _that.label, _that.selected, _that.amount, _that.type);
    case _:
      return null;
  }
}