when<TResult extends Object?> method

  1. @optionalTypeArgs
TResult when<TResult extends Object?>(
  1. TResult $default(
    1. String? id,
    2. int? quantity,
    3. CartLineCost? cost,
    4. ProductVariant? merchandise,
    5. String? variantId,
    6. List<CartDiscountAllocation?>? discountAllocations,
    7. SellingPlanAllocation? sellingPlanAllocation,
    8. List<Attribute?>? attributes,
    )
)

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? id,  int? quantity,  CartLineCost? cost,  ProductVariant? merchandise,  String? variantId,  List<CartDiscountAllocation?>? discountAllocations,  SellingPlanAllocation? sellingPlanAllocation,  List<Attribute?>? attributes)  $default,) {final _that = this;
switch (_that) {
case _Line():
return $default(_that.id,_that.quantity,_that.cost,_that.merchandise,_that.variantId,_that.discountAllocations,_that.sellingPlanAllocation,_that.attributes);case _:
  throw StateError('Unexpected subclass');

}
}