Remade ItemOverview with Generics, and fixed tests

src/main/java/no/ntnu/idatt1002/demo/data/Economics/ItemRegister.java

 package no.ntnu.idatt1002.demo.data.Economics;
 
 import java.util.ArrayList;
+import java.util.Objects;
+import java.util.Set;
+import java.util.stream.Collectors;
 
 /**
- * ItemOverview is an abstract class for storing and getting.
- * information on items. Superclass for Income- and ExpenseOverview.
+ * ItemRegister is a generic class used by ExpenseRegister and
+ * IncomeRegister.
+ * @param <T>   Income or Expense
  */
-public class ItemOverview<T>{
+public class ItemRegister<T>{
     ArrayList<T> items;
 
     /**
      * An "empty" class constructor.
      */
-    public ItemOverview() {
-        this.items = new ArrayList<>();   //ArrayList for storing item´s
+    public ItemRegister() {
+        this.items = new ArrayList<>();   //ArrayList for storing T´s
     }
 
     /**
-     * Class constructor that takes in an ArrayList of Item´s as argument.
-     * @param items An ArrayList of the Item´s you want to overview.
+     * Class constructor that takes in an ArrayList of T as argument.
+     * @param items  An ArrayList of Income or Expense you want to overview.
      */
-    public ItemOverview(ArrayList<T> items) {
+    public ItemRegister(ArrayList<T> items) {
         this.items = items;
     }
 
     /**
-     * Get an ArrayList of every item.
-     * @return item ArrayList.
+     * Get an ArrayList of every T.
+     * @return  T ArrayList.
      */
     public ArrayList<T> getItems() {
         return items;
     }
 
+    /**
+     * Add a new T to the register. Throws IllegalArgumentException
+     * if the new T is already registered.
+     * @param newItem   The T you want to add.
+     */
     public void addItem(T newItem){
         if(items.contains(newItem)){
             throw new IllegalArgumentException("This item is already registered");
@@ -39,14 +48,22 @@ public class ItemOverview<T>{
         items.add(newItem);
     }
 
-
-
     /**
-     * Get the sum of all Item´s in items.
-     * @return Sum of all Item´s.
+     * Get the sum of all T´s in items.
+     * @return   Sum of all T´s.
      */
     public double getTotalSum(){
-        ArrayList<Item> castedItems = (ArrayList<Item>) items;
+        ArrayList<Item> castedItems = (ArrayList<Item>) items; //Casts items as an ArrayList of Item´s
         return castedItems.stream().map(Item::getAmount).mapToDouble(Double::doubleValue).sum();
     }
+
+    public <S> ArrayList<T> getItemsBasedOnCategory(S Category){
+        if(Category instanceof IncomeCategory){ //Checks if it´s an instance of IncomeCategory
+            ArrayList<Income> castedIncome = (ArrayList<Income>) items;
+            return (ArrayList<T>) castedIncome.stream().filter(anIncome -> anIncome.getCategory().compareTo((IncomeCategory) Category) == 0).collect(Collectors.toList());
+        } else if(Category instanceof ExpenseCategory){ //Checks if it´s an instance of ExpenseCategory
+            ArrayList<Expense> castedExpenses = (ArrayList<Expense>) items;
+            return (ArrayList<T>) castedExpenses.stream().filter(anExpense -> anExpense.getCategory().compareTo((ExpenseCategory) Category) == 0).collect(Collectors.toList());
+        } else{return null;}
+    }
 }

src/test/java/no/ntnu/idatt1002/demo/data/Economics/ItemRegisterTest.java

@@ -2,57 +2,129 @@ package no.ntnu.idatt1002.demo.data.Economics;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
 
 import java.util.ArrayList;
 
 import static org.junit.jupiter.api.Assertions.*;
 
-public class IncomeOverviewTest {
+public class ItemRegisterTest {
     ItemRegister<Income> incomeRegister;
+    ItemRegister<Expense> expenseRegister;
 
-    @BeforeEach
-    public void createItemOverView(){
-        incomeRegister = new ItemRegister();
-    }
-    @Test
-    @DisplayName("addItem method throws exception when it should")
-    void addItemThrows(){
-        Income income = new Income("description", 59.9f, false, IncomeCategory.SALARY, "03.03.23");
-        assertThrows(IllegalArgumentException.class, () -> {
-            incomeRegister.addItem(income);
-            incomeRegister.addItem(income);});
-    }
+    @Nested
+    @DisplayName("Test ItemRegister when using Income")
+    class incomeRegisterTests {
+        @BeforeEach
+        public void createItemOverView() {
+            incomeRegister = new ItemRegister();
+        }
 
-    @Test
-    @DisplayName("addItem method does not throw exception when it should not")
-    void addItemDoesNotThrow(){
-        Income income1 = new Income("description", 59.9f, false, IncomeCategory.GIFT, "03.03.23");
-        Income income2 = new Income("anotherDescription", 6.5f, true, IncomeCategory.SALARY, "02.03.23");
-        assertDoesNotThrow(() -> {
-            incomeRegister.addItem(income1); incomeRegister.addItem(income2);});
-    }
+        @Test
+        @DisplayName("addItem method throws exception when it should")
+        void addItemThrows() {
+            Income income = new Income("description", 59.9f, false, IncomeCategory.SALARY, "03.03.23");
+            assertThrows(IllegalArgumentException.class, () -> {
+                incomeRegister.addItem(income);
+                incomeRegister.addItem(income);
+            });
+        }
+
+        @Test
+        @DisplayName("addItem method does not throw exception when it should not")
+        void addItemDoesNotThrow() {
+            Income income1 = new Income("description", 59.9f, false, IncomeCategory.GIFT, "03.03.23");
+            Income income2 = new Income("anotherDescription", 6.5f, true, IncomeCategory.SALARY, "02.03.23");
+            assertDoesNotThrow(() -> {
+                incomeRegister.addItem(income1);
+                incomeRegister.addItem(income2);
+            });
+        }
+
+        @Test
+        @DisplayName("getTotalSum method gives correct amount")
+        void getTotalSumCorrectAmount() {
+            Income income1 = new Income("description1", 59.9f, false, IncomeCategory.SALARY, "03.03.23");
+            Income income2 = new Income("description2", 62.4f, true, IncomeCategory.GIFT, "01.02.21");
+            Income income3 = new Income("description3", 9.81f, false, IncomeCategory.SALARY, "05.07.23");
+            incomeRegister.addItem(income1);
+            incomeRegister.addItem(income2);
+            incomeRegister.addItem(income3);
+
+            double totalIncome = 59.9f + 62.4f + 9.81f;
+            assertEquals(Math.round(incomeRegister.getTotalSum()), Math.round(totalIncome));
+        }
+
+        @Test
+        void getIncomeBasedOnCategoryGivesCorrectIncome() {
+            Income income1 = new Income("description1", 59.9f, false, IncomeCategory.SALARY, "03.03.23");
+            Income income2 = new Income("description2", 62.4f, true, IncomeCategory.GIFT, "01.02.21");
+            Income income3 = new Income("description3", 9.81f, false, IncomeCategory.SALARY, "05.07.23");
 
-    @Test
-    @DisplayName("getTotalSum method gives correct amount")
-    void getTotalSumCorrectAmount(){
-        incomeRegister.addItem(new Income("description1", 59.9f, false, IncomeCategory.SALARY, "03.03.23"));
-        incomeRegister.addItem(new Income("description2", 62.4f, true, IncomeCategory.GIFT, "01.02.21"));
-        incomeRegister.addItem(new Income("description3", 9.81f, false, IncomeCategory.SALARY, "05.07.23"));
-        double totalIncome = 59.9f + 62.4f + 9.81f;
-        System.out.println(incomeRegister.getTotalSum());
-        assertEquals(Math.round(incomeRegister.getTotalSum()), Math.round(totalIncome));
+            incomeRegister.addItem(income1);
+            incomeRegister.addItem(income2);
+            incomeRegister.addItem(income3);
+            ArrayList<Income> incomeSalary = incomeRegister.getItemsBasedOnCategory(IncomeCategory.SALARY);
+            assertTrue(incomeSalary.contains(income1) && incomeSalary.contains(income3));
+        }
     }
 
-    @Test
-    void getIncomeBasedOnCategoryGivesCorrectIncome(){
-        incomeRegister.addItem(new Income("description1", 59.9f, false, IncomeCategory.SALARY, "03.03.23"));
-        incomeRegister.addItem(new Income("description2", 62.4f, true, IncomeCategory.GIFT, "01.02.21"));
-        incomeRegister.addItem(new Income("description3", 9.81f, false, IncomeCategory.SALARY, "05.07.23"));
-        ArrayList<Income> incomeCategory = new ArrayList<>();
-        incomeCategory.add(new Income("description1", 59.9f, false, IncomeCategory.SALARY, "03.03.23"));
-        incomeCategory.add(new Income("description3", 9.81f, false, IncomeCategory.SALARY, "05.07.23"));
-        assertEquals(incomeRegister.getItemsBasedOnCategory(IncomeCategory.SALARY), incomeCategory);
+    @Nested
+    @DisplayName("Test ItemRegister when using Expense")
+    class expenseRegisterTests {
+        @BeforeEach
+        public void createItemOverView() {
+            expenseRegister = new ItemRegister();
+        }
+
+        @Test
+        @DisplayName("addItem method throws exception when it should")
+        void addItemThrows() {
+            Expense expense = new Expense("description", 59.9f, false, ExpenseCategory.CLOTHES, "03.03.23");
+            assertThrows(IllegalArgumentException.class, () -> {
+                expenseRegister.addItem(expense);
+                expenseRegister.addItem(expense);
+            });
+        }
+
+        @Test
+        @DisplayName("addItem method does not throw exception when it should not")
+        void addItemDoesNotThrow() {
+            Expense expense1 = new Expense("description", 59.9f, false, ExpenseCategory.CLOTHES, "03.03.23");
+            Expense expense2 = new Expense("anotherDescription", 6.5f, true, ExpenseCategory.BOOKS, "02.03.23");
+            assertDoesNotThrow(() -> {
+                expenseRegister.addItem(expense1);
+                expenseRegister.addItem(expense2);
+            });
+        }
+
+        @Test
+        @DisplayName("getTotalSum method gives correct amount")
+        void getTotalSumCorrectAmount(){
+            Expense expense1 = new Expense("description1", 59.9f, false, ExpenseCategory.CLOTHES, "03.03.23");
+            Expense expense2 = new Expense("description2", 62.4f, true, ExpenseCategory.FOOD, "01.02.21");
+            Expense expense3 = new Expense("description3", 9.81f, false, ExpenseCategory.CLOTHES, "05.07.23");
+
+            expenseRegister.addItem(expense1);
+            expenseRegister.addItem(expense2);
+            expenseRegister.addItem(expense3);
+            double totalIncome = 59.9f + 62.4f + 9.81f;
+            assertEquals(Math.round(expenseRegister.getTotalSum()), Math.round(totalIncome));
+        }
+
+        @Test
+        void getIncomeBasedOnCategoryGivesCorrectIncome() {
+            Expense expense1 = new Expense("description1", 59.9f, false, ExpenseCategory.CLOTHES, "03.03.23");
+            Expense expense2 = new Expense("description2", 62.4f, true, ExpenseCategory.FOOD, "01.02.21");
+            Expense expense3 = new Expense("description3", 9.81f, false, ExpenseCategory.CLOTHES, "05.07.23");
+
+            expenseRegister.addItem(expense1);
+            expenseRegister.addItem(expense2);
+            expenseRegister.addItem(expense3);
+            ArrayList<Expense> expenseSalary = expenseRegister.getItemsBasedOnCategory(ExpenseCategory.CLOTHES);
+            assertTrue(expenseSalary.contains(expense1) && expenseSalary.contains(expense3));
+        }
     }
 }
  
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