Add test for list of products

.github/workflows/github-actions.yml

@@ -13,6 +13,7 @@ jobs:
           distribution: 'adopt'
       - name: Lint
         run: mvn checkstyle:check
+
   test:
     name: Unit tests
     runs-on: ubuntu-latest

src/main/java/pl/edu/agh/mwo/invoice/Invoice.java

@@ -1,18 +1,19 @@
 package pl.edu.agh.mwo.invoice;
 
+import pl.edu.agh.mwo.invoice.product.Product;
+
 import java.math.BigDecimal;
-import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.Map;
 
-import pl.edu.agh.mwo.invoice.product.Product;
-
 public class Invoice {
-    private Map<Product, Integer> products = new HashMap<>();
+    private final Map<Product, Integer> products = new LinkedHashMap<>();
     private static int nextNumber = 0;
     private final int number = ++nextNumber;
 
     public void addProduct(Product product) {
-        addProduct(product, 1);
+        int actualCount = products.getOrDefault(product, 0);
+        addProduct(product, actualCount + 1);
     }
 
     public void addProduct(Product product, Integer quantity) {
@@ -47,4 +48,15 @@ public BigDecimal getGrossTotal() {
     public int getNumber() {
         return number;
     }
+
+    public String getProductsList() {
+        StringBuilder productsList = new StringBuilder("Invoice: " + getNumber()).append("\n");
+        for (Map.Entry<Product, Integer> entry : products.entrySet()) {
+            Product product = entry.getKey();
+            productsList.append("%s, %d, %s\n".formatted(product.getName(), entry.getValue(), product.getPrice()));
+        }
+        productsList.append("-----\n");
+        productsList.append("Liczba pozycji: ").append(products.values().stream().mapToInt(e -> e).sum()).append("\n");
+        return productsList.toString();
+    }
 }

src/main/java/pl/edu/agh/mwo/invoice/product/Product.java

@@ -1,6 +1,7 @@
 package pl.edu.agh.mwo.invoice.product;
 
 import java.math.BigDecimal;
+import java.util.Objects;
 
 public abstract class Product {
     private final String name;
@@ -10,7 +11,7 @@ public abstract class Product {
     private final BigDecimal taxPercent;
 
     protected Product(String name, BigDecimal price, BigDecimal tax) {
-        if (name == null || name.equals("")
+        if (name == null || name.isEmpty()
                 || price == null || tax == null || tax.compareTo(new BigDecimal(0)) < 0
                 || price.compareTo(new BigDecimal(0)) < 0) {
             throw new IllegalArgumentException();
@@ -35,4 +36,17 @@ public BigDecimal getTaxPercent() {
     public BigDecimal getPriceWithTax() {
         return price.multiply(taxPercent).add(price);
     }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Product product = (Product) o;
+        return Objects.equals(name, product.name) && Objects.equals(price, product.price) && Objects.equals(taxPercent, product.taxPercent);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(name, price, taxPercent);
+    }
 }

src/main/java/pl/edu/agh/mwo/invoice/product/TaxFreeProduct.java

@@ -7,3 +7,4 @@ public TaxFreeProduct(String name, BigDecimal price) {
         super(name, price, BigDecimal.ZERO);
     }
 }
+//komentarz

src/test/java/pl/edu/agh/mwo/invoice/InvoiceTest.java

@@ -150,4 +150,94 @@ public void testTheFirstInvoiceNumberIsLowerThanTheSecond() {
         int number2 = new Invoice().getNumber();
         Assert.assertThat(number1, Matchers.lessThan(number2));
     }
+
+    @Test
+    public void testListOfProducts() {
+        invoice.addProduct(new TaxFreeProduct("Owoce", new BigDecimal("200")));
+        invoice.addProduct(new TaxFreeProduct("Owoce", new BigDecimal("200")));
+        invoice.addProduct(new DairyProduct("Maslanka", new BigDecimal("100")));
+        invoice.addProduct(new OtherProduct("Wino", new BigDecimal("10")));
+        String productsList = invoice.getProductsList();
+        String expectedList = """
+                Invoice: 1
+                Owoce, 2, 200
+                Maslanka, 1, 100
+                Wino, 1, 10
+                -----
+                Liczba pozycji: 4
+                """;
+        Assert.assertThat(productsList, Matchers.equalTo(expectedList));
+    }
+
+    @Test
+    public void testListOfProductsWhenEmptyInvoice() {
+        String expected = """
+        Invoice: %d
+        -----
+        Liczba pozycji: 0
+        """.formatted(invoice.getNumber());
+
+        Assert.assertEquals(expected, invoice.getProductsList());
+    }
+
+    @Test
+    public void testListOfProductsMergesSameProduct() {
+        Product chleb = new TaxFreeProduct("Chleb", new BigDecimal("4.00"));
+        invoice.addProduct(chleb);
+        invoice.addProduct(chleb, 2);
+        String expected = """
+        Invoice: %d
+        Chleb, 3, 4.00
+        -----
+        Liczba pozycji: 3
+        """.formatted(invoice.getNumber());
+
+        Assert.assertEquals(expected, invoice.getProductsList());
+    }
+
+    @Test
+    public void testListOfProductsWithDecimalPrice() {
+        invoice.addProduct(new OtherProduct("Kawa", new BigDecimal("10.55")));
+
+        String expected = """
+        Invoice: %d
+        Kawa, 1, 10.55
+        -----
+        Liczba pozycji: 1
+        """.formatted(invoice.getNumber());
+        Assert.assertEquals(expected, invoice.getProductsList());
+    }
+
+
+
+    @Test
+    public void testAddingSameProductMultipleTimesIsEquivalentToOneAddWithQuantity() {
+        Product długopis = new OtherProduct("Długopis", new BigDecimal("2.50"));
+
+        Invoice invoiceA = new Invoice();
+        invoiceA.addProduct(długopis);
+        invoiceA.addProduct(długopis, 2);
+
+        Invoice invoiceB = new Invoice();
+        invoiceB.addProduct(długopis, 3);
+
+        Assert.assertEquals(invoiceA.getNetTotal(), invoiceB.getNetTotal());
+        Assert.assertEquals(invoiceA.getGrossTotal(), invoiceB.getGrossTotal());
+    }
+
+    @Test
+    public void testProductIsNotDuplicatedInMap() {
+        Product długopis = new OtherProduct("Długopis", new BigDecimal("2.50"));
+        invoice.addProduct(długopis);
+        invoice.addProduct(długopis);
+
+        String expected = """
+        Invoice: %d
+        Długopis, 2, 2.50
+        -----
+        Liczba pozycji: 2
+        """.formatted(invoice.getNumber());
+
+        Assert.assertEquals(expected, invoice.getProductsList());
+    }
 }