feat: created SavingsAccount and corresponding test; Created abstract class BankAccount that extends to SavingsAccount and CheckingAccount; Created MoneyOrder and corresponding test; Updated classes to take BankAccount instead of Checking Account where necessary;

Author: “A1-4U2T1NN”

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BankAccount.java

@@ -4,7 +4,7 @@
 import java.util.Set;
 
 public abstract class BankAccount {
-  protected  final Set<Customer> owners;
+  protected final Set<Customer> owners;
   protected final String accountNumber;
   protected double balance;
   protected boolean isActive;

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BankAtm.java

@@ -46,7 +46,7 @@ public Set<CheckingAccount> findAccountsByCustomerId(UUID customerId) {
    * @param amount The amount to deposit.
    */
   public void depositFunds(String accountNumber, double amount) {
-    CheckingAccount account = getAccountOrThrow(accountNumber);
+    BankAccount account = getAccountOrThrow(accountNumber);
     account.deposit(amount);
   }
 

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CheckingAccount.java

@@ -3,7 +3,7 @@
 import java.util.Set;
 
 /** Represents a checking account. */
-public class CheckingAccount extends BankAccount{
+public class CheckingAccount extends BankAccount {
 
   /**
    * Creates a new checking account.

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/MoneyOrder.java

@@ -0,0 +1,18 @@
+package com.codedifferently.lesson17.bank;
+
+public class MoneyOrder {
+  private final BankAccount account;
+  private final double amount;
+
+  public MoneyOrder(BankAccount account, double amount) {
+    this.account = account;
+    this.amount = amount;
+
+    account.withdraw(amount);
+  }
+  
+  public String getAmount() {
+    return "$" + amount + " Taken from: " + account;
+  }
+}
+

lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/SavingsAccount.java

@@ -3,7 +3,7 @@
 import java.util.Set;
 
 /** Represents a checking account. */
-public class SavingsAccount extends BankAccount{
+public class SavingsAccount extends BankAccount {
 
   /**
    * Creates a new checking account.
@@ -16,22 +16,26 @@ public SavingsAccount(String accountNumber, Set<Customer> owners, double initial
     super(accountNumber, owners, initialBalance);
   }
 
+   public void writeCheck(double amount) {
+    throw new UnsupportedOperationException("Cannot write checks against savings accounts.");
+  }
+
   @Override
   public int hashCode() {
     return accountNumber.hashCode();
   }
 
   @Override
   public boolean equals(Object obj) {
-    if (obj instanceof CheckingAccount other) {
+    if (obj instanceof SavingsAccount other) {
       return accountNumber.equals(other.accountNumber);
     }
     return false;
   }
 
   @Override
   public String toString() {
-    return "CheckingAccount{"
+    return "SavingsAccount{"
         + "accountNumber='"
         + accountNumber
         + '\''

lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/MoneyOrderTest.java

@@ -0,0 +1,42 @@
+package com.codedifferently.lesson17.bank;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class MoneyOrderTest {
+
+  private BankAccount account;
+
+  @BeforeEach
+  public void setup() {
+    // Arrange
+    account = new CheckingAccount("12345678", null, 999.0);
+  }
+
+  @Test
+  public void testMoneyOrderCreation() {
+    //Arrange
+    double expectedAccountAmmount = 499.00;
+    
+    // Act
+    MoneyOrder moneyOrder = new MoneyOrder(account, 500.0);
+
+    // Assert
+    assertEquals(expectedAccountAmmount, account.balance);
+  }
+
+
+  @Test
+  public void testMoneyOrderGetAmmount() {
+    // Act
+    MoneyOrder moneyOrder = new MoneyOrder(account, 500.0);
+
+    // Arrange
+    String expectedMessage = "$" + 500.0 + " Taken from: " + account;
+
+    // Assert
+    assertEquals(expectedMessage, moneyOrder.getAmount());
+  }
+}

lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/SavingsAccountTest.java

@@ -3,17 +3,16 @@
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import com.codedifferently.lesson17.bank.exceptions.InsufficientFundsException;
 import java.util.HashSet;
 import java.util.Set;
 import java.util.UUID;
-
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-import com.codedifferently.lesson17.bank.exceptions.InsufficientFundsException;
-
 public class SavingsAccountTest {
   private SavingsAccount classUnderTest;
   private Set<Customer> owners;
@@ -104,4 +103,21 @@ void toStringTest() {
     String expected = "SavingsAccount{accountNumber='123456789', balance=100.0, isActive=true}";
     assertEquals(expected, classUnderTest.toString());
   }
+
+   @Test
+  void testWriteCheck() {
+    // Arrange
+    SavingsAccount account = new SavingsAccount("12345678", null, 1000.00);
+
+    // Act 
+    UnsupportedOperationException thrown =
+        assertThrows(
+            UnsupportedOperationException.class,
+            () -> {
+              account.writeCheck(100);
+            });
+
+    // Assert
+    assertEquals("Cannot write checks against savings accounts.", thrown.getMessage());
+  }
 }