whenOrNull<TResult extends Object?> method

@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? $default(@JsonKey.new(name: 'address_line_1') String? addressLine1, @JsonKey.new(name: 'address_line_2') String? addressLine2, @JsonKey.new(name: 'admin_area_1') String? adminArea1, @JsonKey.new(name: 'admin_area_2') String? adminArea2, String? postalCode, String? countryCode,)?)

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(
          @JsonKey(name: 'address_line_1') String? addressLine1,
          @JsonKey(name: 'address_line_2') String? addressLine2,
          @JsonKey(name: 'admin_area_1') String? adminArea1,
          @JsonKey(name: 'admin_area_2') String? adminArea2,
          String? postalCode,
          String? countryCode)?
      $default,
) {
  final _that = this;
  switch (_that) {
    case _PPOrderAddress() when $default != null:
      return $default(
          _that.addressLine1,
          _that.addressLine2,
          _that.adminArea1,
          _that.adminArea2,
          _that.postalCode,
          _that.countryCode);
    case _:
      return null;
  }
}