Design Patterns: Ensure Substitutability of Subclasses using LSP

Problem Statement:

A lab to follow the LSP principle while doing your code in C#.

• Do refer to the below Payment class with common properties and methods.
• Create subclasses for payment methods like CreditCard, PayPal, and CryptoCurrency.
• Ensure that substituting one payment method for another does not disrupt the payment processing flow.

Payment Class:

public class Payment
{
    public string Amount { get; set; }
    public string Currency { get; set; }
    public virtual string ProcessPayment()
    {
        // Default payment processing logic
        return "Payment processed successfully.";
    }
}

Lab Objective:

Upon completion of this lab, you will be able to:

• Understand and use the Liskov Substitution Principle (LSP) in class design.
• Create subclasses for different payment methods ensuring substitutability.
• Write tests to verify payment method consistency.
• Identify and resolve any issues in payment method implementation.

Prerequisites

You should install the following software on your machine:

• VS Code or Visual Studio
• .NET SDK