whenOrNull<TResult extends Object?> method

@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? $default(String id, @JsonKey.new(defaultValue: '') String email, String currencyCode, @JsonKey.new(defaultValue: '') String customerUrl, LineItemsOrder lineItems, String name, int orderNumber, String processedAt, ShippingAddress? shippingAddress, ShippingAddress? billingAddress, String statusUrl, @JsonKey.new(fromJson: _priceOrZero) PriceV2 subtotalPrice, PriceV2 totalPrice, PriceV2 totalShippingPrice, @JsonKey.new(fromJson: _priceOrZero) PriceV2 totalTax, @JsonKey.new(defaultValue: '') String financialStatus, String fulfillmentStatus, PriceV2? totalRefunded, String? phone, String? cursor, String? canceledAt, String? cancelReason, List<SuccessfulFullfilment>? successfulFulfillments,)?)

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, @JsonKey(defaultValue: '')  String email,  String currencyCode, @JsonKey(defaultValue: '')  String customerUrl,  LineItemsOrder lineItems,  String name,  int orderNumber,  String processedAt,  ShippingAddress? shippingAddress,  ShippingAddress? billingAddress,  String statusUrl, @JsonKey(fromJson: _priceOrZero)  PriceV2 subtotalPrice,  PriceV2 totalPrice,  PriceV2 totalShippingPrice, @JsonKey(fromJson: _priceOrZero)  PriceV2 totalTax, @JsonKey(defaultValue: '')  String financialStatus,  String fulfillmentStatus,  PriceV2? totalRefunded,  String? phone,  String? cursor,  String? canceledAt,  String? cancelReason,  List<SuccessfulFullfilment>? successfulFulfillments)?  $default,) {final _that = this;
switch (_that) {
case _Order() when $default != null:
return $default(_that.id,_that.email,_that.currencyCode,_that.customerUrl,_that.lineItems,_that.name,_that.orderNumber,_that.processedAt,_that.shippingAddress,_that.billingAddress,_that.statusUrl,_that.subtotalPrice,_that.totalPrice,_that.totalShippingPrice,_that.totalTax,_that.financialStatus,_that.fulfillmentStatus,_that.totalRefunded,_that.phone,_that.cursor,_that.canceledAt,_that.cancelReason,_that.successfulFulfillments);case _:
  return null;

}
}