Question

You must write tests for the following:

all tests must be written in JUnit 5.

• Customer Class
  • Checking that the customer number autoincrements with each new customer object created
• Order Class
  • Checking that the order number autoincrements with each new order object created
  • Adding a product that is already in the order
  • Removing a product that is in the order - quantity less than the quantity in the order
  • Removing a product that is in the order - quantity that is greater than or equal to the quantity in the order
  • ===================================================
  • ^{the code for the java classes}

  • public class Customer {
    
            private static int nextNumber = 1;
            private int number;
            private String firstName;
            private String lastName;
            
            /**
             * Represents a customer with customer number (autogenerated), first and last name.
             * @param firstName
             * @param lastName
             */
            public Customer(String firstName, String lastName) {
                    this.number = nextNumber++;
                    this.firstName = firstName;
                    this.lastName = lastName;
            }
    
            /**
             * Returns the first name
             * @return the first name
             */
            public String getFirstName() {
                    return firstName;
            }
    
            /**
             * Returns the last name
             * @return the last name
             */
            public String getLastName() {
                    return lastName;
            }
            
            /**
             * Sets the first name
             * @param firstName
             */
            public void setFirstName(String firstName) {
                    this.firstName = firstName;
            }
            
            /**
             * Sets the last name
             * @param lastName
             */
            public void setLastName(String lastName) {
                    this.lastName = lastName;
            }
            
            /**
             * Returns the customer number
             * @return the customer number
             */
            public int getNumber() {
                    return number;
            }
    
            @Override
            public String toString() {
                    return "Customer [number=" + number + ", name=" + firstName + " " + lastName + "]";
            }
    
            /** 
             * Customers are equal *only* if their customer numbers are equal
             * @see java.lang.Object#equals(java.lang.Object)
             */
            @Override
            public boolean equals(Object obj) {
                    if (this == obj)
                            return true;
                    if (obj == null)
                            return false;
                    if (getClass() != obj.getClass())
                            return false;
                    Customer other = (Customer) obj;
                    if (number != other.number)
                            return false;
                    return true;
            }       
    
    }
    

  • =============================================

  • import java.util.HashMap;
    import java.util.Map;
    
    /**
     * Represents an order with an ordernumber (autogenerated), customer, and order lines with products and quantities.
     * 
     * @author kwurst
     * @version Fall 2018
     */
    public class Order {
            
            private static int nextNumber;
            private int number;
            private Customer customer;
            private Map<Product, Integer> lines;
            
            /**
             * Represents an order with an ordernumber (autogenerated), customer, and order lines with products and quantities.
             * @param customer
             */
            public Order(Customer customer) {
                    this.number = nextNumber++;
                    this.customer = customer;
                    this.lines = new HashMap<Product, Integer>();
            }
            
            /**
             * Adds a quantity of a product to the order. If the product is already in the order, increase the order quantity by the quantity.
             * @param product
             * @param quantity must be non-negative
             * @throws IllegalArgumentException if the quantity is negative
             */
            public void addToOrder(Product product, int quantity) {
                    if (quantity < 0) {
                            throw new IllegalArgumentException("Quantity must be non-negative.");
                    }
                    
                    if (lines.containsKey(product)) {
                            lines.put(product, lines.get(product) + quantity);
                    } else {
                            lines.put(product, quantity);
                    }
            }
            
            /**
             * Remove a quantity of a product from the order. If the product is already in the order, decrease the order quantity by the quantity.
             * If the quantity is reduced to zero, remove the product from the order.
             * If the product is in the order, return true. If the product is not in the order, return false.
             * @param product
             * @param quantity must be non-negative
             * @return true if the product was in the order, false otherwise
             */
            public boolean removeFromOrder(Product product, int quantity) {
                    if (quantity < 0) {
                            throw new IllegalArgumentException("Quantity must be non-negative.");
                    }
                    
                    if (lines.containsKey(product)) {
                            if (lines.get(product) <= quantity) {
                                    lines.remove(product);
                            } else {
                                    lines.put(product, lines.get(product) - quantity);
                            }
                            return true;
                    } else {
                            return false;
                    }
            }
            
            /**
             * Determine if a product is in the order
             * @param product to check for
             * @return whether the product is in the order
             */
            public boolean contains(Product product) {
                    return lines.containsKey(product);
            }
            
            /**
             * Determine the quantity of a product in the order
             * @param product to check
             * @return quantity of the product in the order
             */
            public int getItemQuantity(Product product) {
                    if (contains(product)) {
                            return lines.get(product);
                    } else {
                            return 0;
                    }
            }
            
            /**
             * Returns the total cost of the order (unit prices * quantity)
             * @return the total cost of the order (unit prices * quantity)
             */
            public double getOrderTotal() {
                    double total = 0;
                    
                    for (Map.Entry<Product,Integer> entry : lines.entrySet()) {
                        Product key = entry.getKey();
                        Integer value = entry.getValue();
                        total += key.getUnitPrice() * value;
                    }
                    
                    return total;
            }
            
            /**
             * Returns the number of order lines.
             * @return the number of order lines
             */
            public int getOrderLineCount() {
                    return lines.size();
            }
            
            /**
             * Returns the number of items in the order (sum of quantity of all lines)
             * @returnthe number of items in the order (sum of quantity of all lines)
             */
            public int getOrderItemCount() {
                    int total = 0;
                    
                    for (Map.Entry<Product,Integer> entry : lines.entrySet()) {
                        total += entry.getValue();
                    }
                    
                    return total;
            }
    
            @Override
            public String toString() {
                    return "Order [number=" + number + ", customer=" + customer + ", lines=" + lines + "]";
            }
    
            /** 
             * Orders are equal *only* if their order numbers are equal
             * @see java.lang.Object#equals(java.lang.Object)
             */
            @Override
            public boolean equals(Object obj) {
                    if (this == obj)
                            return true;
                    if (obj == null)
                            return false;
                    if (getClass() != obj.getClass())
                            return false;
                    Order other = (Order) obj;
                    if (number != other.number)
                            return false;
                    return true;
            }
            
    }
    

  • =====================================================

  • public class Product {
            
            private String sku;
            private double unitPrice;
            private String description;
            
            /**
             * Represents a Product with a SKU number, unit price, and description.
             * 
             * @param sku
             * @param unitPrice must be non-negative
             * @param description
             */
            public Product(String sku, double unitPrice, String description) {
                    if (unitPrice < 0) {
                            throw new IllegalArgumentException("Unit price must be non-negative.");
                    }
                    this.sku = sku;
                    this.unitPrice = unitPrice;
                    this.description = description;
            }
    
            /**
             * Returns the unit price
             * @return unit price
             */
            public double getUnitPrice() {
                    return unitPrice;
            }
    
            /**
             * Sets the unit price
             * @param unitPrice must be non-negative
             */
            public void setUnitPrice(double unitPrice) {
                    if (unitPrice < 0) {
                            throw new IllegalArgumentException("Unit price must be non-negative.");
                    }
                    this.unitPrice = unitPrice;
            }
    
            /**
             * Returns the description
             * @return the description
             */
            public String getDescription() {
                    return description;
            }
    
            /**
             * Sets the description
             * @param description
             */
            public void setDescription(String description) {
                    this.description = description;
            }
    
            /**
             * Returns the SKU number
             * @return the SKU number
             */
            public String getSku() {
                    return sku;
            }
    
            @Override
            public String toString() {
                    return "Product [sku=" + sku + ", unitPrice=" + unitPrice + ", description=" + description + "]";
            }
    
            /** 
             * Products are equal *only* if their sku numbers are equal
             * @see java.lang.Object#equals(java.lang.Object)
             */
            @Override
            public boolean equals(Object obj) {
                    if (this == obj)
                            return true;
                    if (obj == null)
                            return false;
                    if (getClass() != obj.getClass())
                            return false;
                    Product other = (Product) obj;
                    if (sku == null) {
                            if (other.sku != null)
                                    return false;
                    } else if (!sku.equals(other.sku))
                            return false;
                    return true;
            }       

Answer 1

Hi, Please find the solution and rate the answer. Please note that Junit 5 has not yet released. Latest version is 4.9. I have used 4.9 for this program.

import org.junit.Test;

import java.util.Random;

public class TEst {
    String getRandomString(int size){
        Random random = new Random();
        int rSize = Math.abs(random.nextInt() % size + 1);
        String sample = "abcdefghijklmnopqrstuvwxyz0123456789";
        String retStr="";
        for (int i = 0; i < rSize; i++) {
            retStr += Character.toString(sample.charAt(Math.abs(random.nextInt()) % 36));
        }
        return retStr;
    }
    @Test
    public void testCustomerNoAutoInc(){
        Customer c = new Customer(getRandomString(5),getRandomString(5));
        Customer c1 = new Customer(getRandomString(5),getRandomString(5));
        assert c1.getNumber()==c.getNumber()+1:"Number not auto incrementing";//Text after colon will print if assert fails
    }

    @Test
    public void testOrderIncrement(){
        Customer c = new Customer(getRandomString(5),getRandomString(5));
        Customer c1 = new Customer(getRandomString(5),getRandomString(5));
        Order o = new Order(c);
        Order o1 = new Order(c1);
        //getNumber method is not present in Order class. PLs do required.
//        assert o.getNumber()+1 = o1.getNumber():"Order number not incrementing";
    }
    @Test
    public void testAddAlreadyInOrder(){
        Customer c = new Customer(getRandomString(5),getRandomString(5));
        Order o = new Order(c);
        Product p = new Product("SKU23423", 2342.22, "Washing machine by Apollo");
        o.addToOrder(p,1);
        o.addToOrder(p,1);
        assert o.getItemQuantity(p) == 2 : "Order not being updated";

    }
    @Test
    public void testRemoveLessThanAlreadyInOrder(){
        Customer c = new Customer(getRandomString(5),getRandomString(5));
        Order o = new Order(c);
        Product p = new Product("SKU23423", 2342.22, "Washing machine by Apollo");
        o.addToOrder(p,2);
        o.removeFromOrder(p,1);
        assert o.getItemQuantity(p) == 1 : "Order was not removed";
    }
    @Test
    public void testRemoveMoreThanAlreadyInOrder(){
        Customer c = new Customer(getRandomString(5),getRandomString(5));
        Order o = new Order(c);
        Product p = new Product("SKU23423", 2342.22, "Washing machine by Apollo");
        o.addToOrder(p,2);
        o.removeFromOrder(p,3);
        assert o.getOrderItemCount() == 0 : "Order was not removed";
    }


}

sAll tests are passing. Below is project structure as a maven project.