Solution: Apply Flexible Discounts for Marketing Campaigns
Explore how to implement the Strategy Pattern to manage discount logic dynamically in a Node.js checkout system. Learn to create independent discount strategies—flat, percentage, and loyalty—that can be swapped at runtime without modifying core service logic. This lesson shows how to keep your code flexible and maintainable by avoiding conditional branching and embracing reusable design patterns.
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Solution explanation
Lines 2–22: We define three discount strategies:
FlatDiscount,PercentageDiscount, andLoyaltyDiscount.Each strategy encapsulates a distinct pricing rule through a
.calculate()method.FlatDiscountapplies a fixed numeric deduction.PercentageDiscountmultiplies the subtotal to simulate a percentage-based reduction.LoyaltyDiscountsimulates a loyalty-tier reduction, representing customer-specific logic.
Lines 25–38: ...