Made ItemOverview abstract, and made subclasses

src/main/java/no/ntnu/idatt1002/demo/data/ExpenseOverview.java

+package no.ntnu.idatt1002.demo.data;
+
+import java.util.ArrayList;
+public class ExpenseOverview {
+    private ArrayList<Expense> expenses;
+
+    public ExpenseOverview(){
+        this.expenses = new ArrayList<>();
+    }
+}

src/main/java/no/ntnu/idatt1002/demo/data/IncomeOverview.java

+package no.ntnu.idatt1002.demo.data;
+
+import java.util.ArrayList;
+
+public class IncomeOverview extends ItemOverview {
+    private ArrayList<Income> income;
+
+    public IncomeOverview(){
+        this.income = new ArrayList<>();
+    }
+}

src/main/java/no/ntnu/idatt1002/demo/data/ItemOverview.java

@@ -7,7 +7,7 @@ import java.util.ArrayList;
  * information on items. It is meant for storing EITHER
  * Income or Expense
  */
-public class ItemOverview {
+public abstract class ItemOverview {
     ArrayList<Item> items;
 
     /**

src/test/java/no/ntnu/idatt1002/demo/data/ItemOverviewTest.java → src/test/java/no/ntnu/idatt1002/demo/data/IncomeOverviewTest.java

@@ -6,35 +6,35 @@ import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.*;
 
-public class ItemOverviewTest {
-    ItemOverview itemOverview;
+public class IncomeOverviewTest {
+    IncomeOverview incomeOverview;
 
     @BeforeEach
     public void createItemOverView(){
-        itemOverview = new ItemOverview();
+        incomeOverview = new IncomeOverview();
     }
     @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, () -> {itemOverview.addItem(income); itemOverview.addItem(income);});
+        assertThrows(IllegalArgumentException.class, () -> {incomeOverview.addItem(income); incomeOverview.addItem(income);});
     }
 
     @Test
     @DisplayName("addItem method does not throw exception when it should not")
     void addItemDoesNotThrow(){
-        Expense expense = new Expense("description", 59.9f, false, ExpenseCategory.CLOTHES, "03.03.23");
+        Income expense = new Income("description", 59.9f, false, IncomeCategory.GIFT, "03.03.23");
         Income income = new Income("anotherDescription", 6.5f, true, IncomeCategory.SALARY, "02.03.23");
-        assertDoesNotThrow(() -> {itemOverview.addItem(expense); itemOverview.addItem(income);});
+        assertDoesNotThrow(() -> {incomeOverview.addItem(expense); incomeOverview.addItem(income);});
     }
 
     @Test
     @DisplayName("getTotalSum method gives correct amount")
     void getTotalSumCorrectAmount(){
-        itemOverview.addItem(new Income("description1", 59.9f, false, IncomeCategory.SALARY, "03.03.23"));
-        itemOverview.addItem(new Income("description2", 62.4f, true, IncomeCategory.GIFT, "01.02.21"));
-        itemOverview.addItem(new Income("description3", 9.81f, false, IncomeCategory.SALARY, "05.07.23"));
+        incomeOverview.addItem(new Income("description1", 59.9f, false, IncomeCategory.SALARY, "03.03.23"));
+        incomeOverview.addItem(new Income("description2", 62.4f, true, IncomeCategory.GIFT, "01.02.21"));
+        incomeOverview.addItem(new Income("description3", 9.81f, false, IncomeCategory.SALARY, "05.07.23"));
         double totalIncome = 59.9f + 62.4f + 9.81f;
-        assertEquals(Math.round(itemOverview.getTotalSum()), Math.round(totalIncome));
+        assertEquals(Math.round(incomeOverview.getTotalSum()), Math.round(totalIncome));
     }
 }
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