Invoice.ts

export class Invoice {
    //...

    public getValue(): Money {
        const total = this.itemsSum();
        if (this.billingDate.after(OurDate.yearEnd(this.openingDate))) {
            if (
                this.originator.getState() === "FL" ||
                this.originator.getState() === "NY"
            ) {
                total.add(this.getLocalShipping());
            } else {
                total.add(this.getDefaultShipping());
            }
        } else {
            total.add(this.getSpanningShipping());
        }
        total.add(this.getTax());
        return total;
    }

    //...
}