From 0e0ec6286c48f8b2697d69a363f0bfb1b9026b76 Mon Sep 17 00:00:00 2001
From: Evan Philakhong <evanphilakhong@mac.mynetworksettings.com>
Date: Sat, 12 Apr 2025 02:31:37 -0400
Subject: [PATCH 1/7] feat: adds Account superclass for CheckingAccount

---
 .../lesson17/bank/Account.java                | 100 +++++++++++++++
 .../lesson17/bank/CheckingAccount.java        | 117 ++----------------
 2 files changed, 110 insertions(+), 107 deletions(-)
 create mode 100644 lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Account.java

diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Account.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Account.java
new file mode 100644
index 000000000..938d86f14
--- /dev/null
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Account.java
@@ -0,0 +1,100 @@
+package com.codedifferently.lesson17.bank;
+
+import com.codedifferently.lesson17.bank.exceptions.InsufficientFundsException;
+
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.Set;
+
+/**
+ * Abstract base class for all bank accounts.
+ */
+@Getter
+@Setter
+public abstract class Account {
+  private final Set<Customer> owners;
+  private final String accountNumber;
+  private double balance;
+  private boolean isActive;
+
+  /**
+   * Creates a new account.
+   *
+   * @param accountNumber The account number.
+   * @param owners        The owners of the account.
+   * @param initalBalance The inital balance of the account.
+   */
+  public Account(String accountNumber, Set<Customer> owners, double initalBalance) {
+    this.accountNumber = accountNumber;
+    this.owners = owners;
+    this.balance = initalBalance;
+    this.isActive = true;
+  }
+
+  /**
+   * Deposits funds into the account.
+   *
+   * @param amount The amount to deposit.
+   */
+  public void deposit(double amount) throws IllegalStateException {
+    if (isClosed()) {
+      throw new IllegalStateException("Cannot deposit to a closed account");
+    }
+    if (amount <= 0) {
+      throw new IllegalArgumentException("Deposit amount must be positive");
+    }
+    balance += amount;
+  }
+
+  /**
+   * Withdraws funds from the account.
+   *
+   * @param amount
+   * @throws InsufficientFundsException
+   */
+  public void withdraw(double amount) throws InsufficientFundsException {
+    if (isClosed()) {
+      throw new IllegalStateException("Cannot withdraw from a closed account");
+    }
+    if (amount <= 0) {
+      throw new IllegalStateException("Withdrawal amount must be positive");
+    }
+    if (balance < amount) {
+      throw new InsufficientFundsException("Account does not have enough funds for withdrawal");
+    }
+    balance -= amount;
+  }
+
+  /**
+   * Closes the account.
+   */
+  public void closeAccount() throws IllegalStateException {
+    if (balance > 0) {
+      throw new IllegalStateException("Cannot close account with a positive balance");
+    }
+    isActive = false;
+  }
+
+  /**
+   * Checks if the account is closed.
+   *
+   * @return True if the account is closed, otherwise false.
+   */
+  public boolean isClosed() {
+    return !isActive;
+  }
+
+  @Override
+  public int hashCode() {
+    return accountNumber.hashCode();
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (obj instanceof CheckingAccount other) {
+      return accountNumber.equals(other.getAccountNumber());
+    }
+    return false;
+  }
+}
diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CheckingAccount.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CheckingAccount.java
index 5d8aeb74d..d7f9c448a 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CheckingAccount.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CheckingAccount.java
@@ -1,131 +1,34 @@
 package com.codedifferently.lesson17.bank;
 
-import com.codedifferently.lesson17.bank.exceptions.InsufficientFundsException;
+import lombok.Getter;
+
 import java.util.Set;
 
 /** Represents a checking account. */
-public class CheckingAccount {
-
-  private final Set<Customer> owners;
-  private final String accountNumber;
-  private double balance;
-  private boolean isActive;
+@Getter
+public class CheckingAccount extends Account {
 
   /**
    * Creates a new checking account.
    *
-   * @param accountNumber The account number.
-   * @param owners The owners of the account.
+   * @param accountNumber  The account number.
+   * @param owners         The owners of the account.
    * @param initialBalance The initial balance of the account.
    */
   public CheckingAccount(String accountNumber, Set<Customer> owners, double initialBalance) {
-    this.accountNumber = accountNumber;
-    this.owners = owners;
-    this.balance = initialBalance;
-    isActive = true;
-  }
-
-  /**
-   * Gets the account number.
-   *
-   * @return The account number.
-   */
-  public String getAccountNumber() {
-    return accountNumber;
-  }
-
-  /**
-   * Gets the owners of the account.
-   *
-   * @return The owners of the account.
-   */
-  public Set<Customer> getOwners() {
-    return owners;
-  }
-
-  /**
-   * Deposits funds into the account.
-   *
-   * @param amount The amount to deposit.
-   */
-  public void deposit(double amount) throws IllegalStateException {
-    if (isClosed()) {
-      throw new IllegalStateException("Cannot deposit to a closed account");
-    }
-    if (amount <= 0) {
-      throw new IllegalArgumentException("Deposit amount must be positive");
-    }
-    balance += amount;
-  }
-
-  /**
-   * Withdraws funds from the account.
-   *
-   * @param amount
-   * @throws InsufficientFundsException
-   */
-  public void withdraw(double amount) throws InsufficientFundsException {
-    if (isClosed()) {
-      throw new IllegalStateException("Cannot withdraw from a closed account");
-    }
-    if (amount <= 0) {
-      throw new IllegalStateException("Withdrawal amount must be positive");
-    }
-    if (balance < amount) {
-      throw new InsufficientFundsException("Account does not have enough funds for withdrawal");
-    }
-    balance -= amount;
-  }
-
-  /**
-   * Gets the balance of the account.
-   *
-   * @return The balance of the account.
-   */
-  public double getBalance() {
-    return balance;
-  }
-
-  /** Closes the account. */
-  public void closeAccount() throws IllegalStateException {
-    if (balance > 0) {
-      throw new IllegalStateException("Cannot close account with a positive balance");
-    }
-    isActive = false;
-  }
-
-  /**
-   * Checks if the account is closed.
-   *
-   * @return True if the account is closed, otherwise false.
-   */
-  public boolean isClosed() {
-    return !isActive;
-  }
-
-  @Override
-  public int hashCode() {
-    return accountNumber.hashCode();
-  }
-
-  @Override
-  public boolean equals(Object obj) {
-    if (obj instanceof CheckingAccount other) {
-      return accountNumber.equals(other.accountNumber);
-    }
-    return false;
+    super(accountNumber, owners, initialBalance);
   }
 
   @Override
   public String toString() {
     return "CheckingAccount{"
         + "accountNumber='"
-        + accountNumber
+        + getAccountNumber()
         + '\''
         + ", balance="
-        + balance
+        + getBalance()
         + ", isActive="
-        + isActive
+        + isActive()
         + '}';
   }
 }

From 1f7acc318ce52bd98ed019317d256344fe2c0e30 Mon Sep 17 00:00:00 2001
From: Evan Philakhong <evanphilakhong@Evans-MacBook-Air.local>
Date: Mon, 14 Apr 2025 09:46:45 -0400
Subject: [PATCH 2/7] feat: immplements SavingsAccount class

---
 .../lesson17/bank/BankAtm.java                | 27 +++++++++-------
 .../codedifferently/lesson17/bank/Check.java  | 10 +++---
 .../lesson17/bank/CheckingAccount.java        |  3 --
 .../lesson17/bank/Customer.java               | 31 ++++++-------------
 .../lesson17/bank/SavingsAccount.java         | 31 +++++++++++++++++++
 .../lesson17/bank/SavingAccountTest.java      | 17 ++++++++++
 6 files changed, 78 insertions(+), 41 deletions(-)
 create mode 100644 lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/SavingsAccount.java
 create mode 100644 lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/SavingAccountTest.java

diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BankAtm.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BankAtm.java
index 8cbcd3cc0..27dbfbada 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BankAtm.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BankAtm.java
@@ -10,14 +10,14 @@
 public class BankAtm {
 
   private final Map<UUID, Customer> customerById = new HashMap<>();
-  private final Map<String, CheckingAccount> accountByNumber = new HashMap<>();
+  private final Map<String, Account> accountByNumber = new HashMap<>();
 
   /**
    * Adds a checking account to the bank.
    *
    * @param account The account to add.
    */
-  public void addAccount(CheckingAccount account) {
+  public void addAccount(Account account) {
     accountByNumber.put(account.getAccountNumber(), account);
     account
         .getOwners()
@@ -33,7 +33,7 @@ public void addAccount(CheckingAccount account) {
    * @param customerId The ID of the customer.
    * @return The unique set of accounts owned by the customer.
    */
-  public Set<CheckingAccount> findAccountsByCustomerId(UUID customerId) {
+  public Set<Account> findAccountsByCustomerId(UUID customerId) {
     return customerById.containsKey(customerId)
         ? customerById.get(customerId).getAccounts()
         : Set.of();
@@ -43,10 +43,10 @@ public Set<CheckingAccount> findAccountsByCustomerId(UUID customerId) {
    * Deposits funds into an account.
    *
    * @param accountNumber The account number.
-   * @param amount The amount to deposit.
+   * @param amount        The amount to deposit.
    */
   public void depositFunds(String accountNumber, double amount) {
-    CheckingAccount account = getAccountOrThrow(accountNumber);
+    Account account = getAccountOrThrow(accountNumber);
     account.deposit(amount);
   }
 
@@ -54,11 +54,16 @@ public void depositFunds(String accountNumber, double amount) {
    * Deposits funds into an account using a check.
    *
    * @param accountNumber The account number.
-   * @param check The check to deposit.
+   * @param check         The check to deposit.
    */
   public void depositFunds(String accountNumber, Check check) {
-    CheckingAccount account = getAccountOrThrow(accountNumber);
-    check.depositFunds(account);
+    Account account = getAccountOrThrow(accountNumber);
+
+    if (account instanceof CheckingAccount checkingAccount) {
+      check.depositFunds(checkingAccount);
+    } else if (account instanceof SavingsAccount) {
+      throw new IllegalStateException("Savings Accounts can't accept checks");
+    }
   }
 
   /**
@@ -68,7 +73,7 @@ public void depositFunds(String accountNumber, Check check) {
    * @param amount
    */
   public void withdrawFunds(String accountNumber, double amount) {
-    CheckingAccount account = getAccountOrThrow(accountNumber);
+    Account account = getAccountOrThrow(accountNumber);
     account.withdraw(amount);
   }
 
@@ -78,8 +83,8 @@ public void withdrawFunds(String accountNumber, double amount) {
    * @param accountNumber The account number.
    * @return The account.
    */
-  private CheckingAccount getAccountOrThrow(String accountNumber) {
-    CheckingAccount account = accountByNumber.get(accountNumber);
+  private Account getAccountOrThrow(String accountNumber) {
+    Account account = accountByNumber.get(accountNumber);
     if (account == null || account.isClosed()) {
       throw new AccountNotFoundException("Account not found");
     }
diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Check.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Check.java
index 061fa4a5c..b4bea73df 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Check.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Check.java
@@ -7,17 +7,17 @@ public class Check {
 
   private final String checkNumber;
   private final double amount;
-  private final CheckingAccount account;
+  private final Account account;
   private boolean isVoided = false;
 
   /**
    * Creates a new check.
    *
    * @param checkNumber The check number.
-   * @param amount The amount of the check.
-   * @param account The account the check is drawn on.
+   * @param amount      The amount of the check.
+   * @param account     The account the check is drawn on.
    */
-  public Check(String checkNumber, double amount, CheckingAccount account) {
+  public Check(String checkNumber, double amount, Account account) {
     if (amount < 0) {
       throw new IllegalArgumentException("Check amount must be positive");
     }
@@ -45,7 +45,7 @@ public void voidCheck() {
    *
    * @param toAccount The account to deposit the check into.
    */
-  public void depositFunds(CheckingAccount toAccount) {
+  public void depositFunds(Account toAccount) {
     if (isVoided) {
       throw new CheckVoidedException("Check is voided");
     }
diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CheckingAccount.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CheckingAccount.java
index d7f9c448a..8c488e1e4 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CheckingAccount.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CheckingAccount.java
@@ -1,11 +1,8 @@
 package com.codedifferently.lesson17.bank;
 
-import lombok.Getter;
-
 import java.util.Set;
 
 /** Represents a checking account. */
-@Getter
 public class CheckingAccount extends Account {
 
   /**
diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
index af0847134..40a66a252 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
@@ -4,17 +4,22 @@
 import java.util.Set;
 import java.util.UUID;
 
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
 /** Represents a customer of the bank. */
 public class Customer {
 
   private final UUID id;
   private final String name;
-  private final Set<CheckingAccount> accounts = new HashSet<>();
+  private final Set<Account> accounts = new HashSet<>();
 
   /**
    * Creates a new customer.
    *
-   * @param id The ID of the customer.
+   * @param id   The ID of the customer.
    * @param name The name of the customer.
    */
   public Customer(UUID id, String name) {
@@ -22,30 +27,12 @@ public Customer(UUID id, String name) {
     this.name = name;
   }
 
-  /**
-   * Gets the ID of the customer.
-   *
-   * @return The ID of the customer.
-   */
-  public UUID getId() {
-    return id;
-  }
-
-  /**
-   * Gets the name of the customer.
-   *
-   * @return The name of the customer.
-   */
-  public String getName() {
-    return name;
-  }
-
   /**
    * Adds a checking account to the customer.
    *
    * @param account The account to add.
    */
-  public void addAccount(CheckingAccount account) {
+  public void addAccount(Account account) {
     accounts.add(account);
   }
 
@@ -54,7 +41,7 @@ public void addAccount(CheckingAccount account) {
    *
    * @return The unique set of accounts owned by the customer.
    */
-  public Set<CheckingAccount> getAccounts() {
+  public Set<Account> getAccounts() {
     return accounts;
   }
 
diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/SavingsAccount.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/SavingsAccount.java
new file mode 100644
index 000000000..9e41bfb99
--- /dev/null
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/SavingsAccount.java
@@ -0,0 +1,31 @@
+package com.codedifferently.lesson17.bank;
+
+import java.util.Set;
+
+/** Represents a savings account. */
+public class SavingsAccount extends Account {
+
+  /**
+   * Creates a new sacings account.
+   *
+   * @param accountNumber The account number.
+   * @param owners        The ownders of the account.
+   * @param initalBalance The inital balance of the account.
+   */
+  public SavingsAccount(String accountNumber, Set<Customer> owners, double initalBalance) {
+    super(accountNumber, owners, initalBalance);
+  }
+
+  @Override
+  public String toString() {
+    return "SavingsAccount{"
+        + "accountNumber='"
+        + getAccountNumber()
+        + '\''
+        + ", balance="
+        + getBalance()
+        + ", isActive="
+        + isActive()
+        + '}';
+  }
+}
diff --git a/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/SavingAccountTest.java b/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/SavingAccountTest.java
new file mode 100644
index 000000000..79d87bf35
--- /dev/null
+++ b/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/SavingAccountTest.java
@@ -0,0 +1,17 @@
+package com.codedifferently.lesson17.bank;
+
+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.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;
+
+class CheckingAccountTest {
+
+}

From 8d69a4ec6a0f9fd6fdef562aea36532cfec0ffca Mon Sep 17 00:00:00 2001
From: Evan Philakhong <evanphilakhong@Evans-MacBook-Air.local>
Date: Mon, 14 Apr 2025 11:43:48 -0400
Subject: [PATCH 3/7] refactor: ran spotlessApply

---
 .../codedifferently/lesson17/bank/Account.java   | 14 ++++----------
 .../codedifferently/lesson17/bank/BankAtm.java   |  4 ++--
 .../com/codedifferently/lesson17/bank/Check.java |  4 ++--
 .../lesson17/bank/CheckingAccount.java           |  4 ++--
 .../codedifferently/lesson17/bank/Customer.java  |  8 +++++---
 .../lesson17/bank/CustomerType.java              |  6 ++++++
 .../lesson17/bank/SavingsAccount.java            |  2 +-
 .../lesson17/bank/SavingAccountTest.java         | 16 +---------------
 8 files changed, 23 insertions(+), 35 deletions(-)
 create mode 100644 lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CustomerType.java

diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Account.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Account.java
index 938d86f14..92e67b7bb 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Account.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Account.java
@@ -1,15 +1,11 @@
 package com.codedifferently.lesson17.bank;
 
 import com.codedifferently.lesson17.bank.exceptions.InsufficientFundsException;
-
+import java.util.Set;
 import lombok.Getter;
 import lombok.Setter;
 
-import java.util.Set;
-
-/**
- * Abstract base class for all bank accounts.
- */
+/** Abstract base class for all bank accounts. */
 @Getter
 @Setter
 public abstract class Account {
@@ -22,7 +18,7 @@ public abstract class Account {
    * Creates a new account.
    *
    * @param accountNumber The account number.
-   * @param owners        The owners of the account.
+   * @param owners The owners of the account.
    * @param initalBalance The inital balance of the account.
    */
   public Account(String accountNumber, Set<Customer> owners, double initalBalance) {
@@ -66,9 +62,7 @@ public void withdraw(double amount) throws InsufficientFundsException {
     balance -= amount;
   }
 
-  /**
-   * Closes the account.
-   */
+  /** Closes the account. */
   public void closeAccount() throws IllegalStateException {
     if (balance > 0) {
       throw new IllegalStateException("Cannot close account with a positive balance");
diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BankAtm.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BankAtm.java
index 27dbfbada..ce0c55725 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BankAtm.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BankAtm.java
@@ -43,7 +43,7 @@ public Set<Account> findAccountsByCustomerId(UUID customerId) {
    * Deposits funds into an account.
    *
    * @param accountNumber The account number.
-   * @param amount        The amount to deposit.
+   * @param amount The amount to deposit.
    */
   public void depositFunds(String accountNumber, double amount) {
     Account account = getAccountOrThrow(accountNumber);
@@ -54,7 +54,7 @@ public void depositFunds(String accountNumber, double amount) {
    * Deposits funds into an account using a check.
    *
    * @param accountNumber The account number.
-   * @param check         The check to deposit.
+   * @param check The check to deposit.
    */
   public void depositFunds(String accountNumber, Check check) {
     Account account = getAccountOrThrow(accountNumber);
diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Check.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Check.java
index b4bea73df..ed813e90d 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Check.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Check.java
@@ -14,8 +14,8 @@ public class Check {
    * Creates a new check.
    *
    * @param checkNumber The check number.
-   * @param amount      The amount of the check.
-   * @param account     The account the check is drawn on.
+   * @param amount The amount of the check.
+   * @param account The account the check is drawn on.
    */
   public Check(String checkNumber, double amount, Account account) {
     if (amount < 0) {
diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CheckingAccount.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CheckingAccount.java
index 8c488e1e4..4adf04f71 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CheckingAccount.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CheckingAccount.java
@@ -8,8 +8,8 @@ public class CheckingAccount extends Account {
   /**
    * Creates a new checking account.
    *
-   * @param accountNumber  The account number.
-   * @param owners         The owners of the account.
+   * @param accountNumber The account number.
+   * @param owners The owners of the account.
    * @param initialBalance The initial balance of the account.
    */
   public CheckingAccount(String accountNumber, Set<Customer> owners, double initialBalance) {
diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
index 40a66a252..f95a50092 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
@@ -3,7 +3,6 @@
 import java.util.HashSet;
 import java.util.Set;
 import java.util.UUID;
-
 import lombok.Getter;
 import lombok.Setter;
 
@@ -14,17 +13,20 @@ public class Customer {
 
   private final UUID id;
   private final String name;
+  private final CustomerType type;
   private final Set<Account> accounts = new HashSet<>();
 
   /**
    * Creates a new customer.
    *
-   * @param id   The ID of the customer.
+   * @param id The ID of the customer.
    * @param name The name of the customer.
+   * @param type The type of customer (individual or business)
    */
-  public Customer(UUID id, String name) {
+  public Customer(UUID id, String name, CustomerType type) {
     this.id = id;
     this.name = name;
+    this.type = type;
   }
 
   /**
diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CustomerType.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CustomerType.java
new file mode 100644
index 000000000..30f05a33c
--- /dev/null
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/CustomerType.java
@@ -0,0 +1,6 @@
+package com.codedifferently.lesson17.bank;
+
+public enum CustomerType {
+  INDIVIDUAL,
+  BUSINESS
+}
diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/SavingsAccount.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/SavingsAccount.java
index 9e41bfb99..411cf060d 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/SavingsAccount.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/SavingsAccount.java
@@ -9,7 +9,7 @@ public class SavingsAccount extends Account {
    * Creates a new sacings account.
    *
    * @param accountNumber The account number.
-   * @param owners        The ownders of the account.
+   * @param owners The ownders of the account.
    * @param initalBalance The inital balance of the account.
    */
   public SavingsAccount(String accountNumber, Set<Customer> owners, double initalBalance) {
diff --git a/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/SavingAccountTest.java b/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/SavingAccountTest.java
index 79d87bf35..fcf14b237 100644
--- a/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/SavingAccountTest.java
+++ b/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/SavingAccountTest.java
@@ -1,17 +1,3 @@
 package com.codedifferently.lesson17.bank;
 
-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.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;
-
-class CheckingAccountTest {
-
-}
+class CheckingAccountTest {}

From 04be46f6996cd91b8047bef500f99721fceed2fe Mon Sep 17 00:00:00 2001
From: Evan Philakhong <evanphilakhong@Evans-MacBook-Air.local>
Date: Mon, 14 Apr 2025 15:30:28 -0400
Subject: [PATCH 4/7] feat: adds BusinessCheckingAccount class

---
 .../codedifferently/lesson17/bank/Customer.java   | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
index f95a50092..62b9716f1 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
@@ -19,7 +19,7 @@ public class Customer {
   /**
    * Creates a new customer.
    *
-   * @param id The ID of the customer.
+   * @param id   The ID of the customer.
    * @param name The name of the customer.
    * @param type The type of customer (individual or business)
    */
@@ -29,6 +29,19 @@ public Customer(UUID id, String name, CustomerType type) {
     this.type = type;
   }
 
+  /**
+   * Creates an new individual customer.
+   *
+   * @param id   The ID of the customer.
+   * @param name The name of the customer.
+   * @param type The type of custimer (individual or business)
+   */
+  public Customer(UUID id, String name, Customer type) {
+    this.id = id;
+    this.name = name;
+    this.type = CustomerType.INDIVIDUAL;
+  }
+
   /**
    * Adds a checking account to the customer.
    *

From a6f21fac4667ac1f96d9d727eb7f01552e94a60d Mon Sep 17 00:00:00 2001
From: Evan Philakhong <evanthegamer2004@gmail.com>
Date: Wed, 16 Apr 2025 13:57:28 +0000
Subject: [PATCH 5/7] feat: adds SavingsAccount Tests

---
 .../bank/BusinessCheckingAccount.java         | 32 +++++++++
 .../codedifferently/lesson17/bank/Check.java  |  4 +-
 .../lesson17/bank/Customer.java               |  6 +-
 .../lesson17/bank/BankAtmTest.java            |  4 +-
 .../lesson17/bank/SavingAccountTest.java      | 66 ++++++++++++++++++-
 5 files changed, 104 insertions(+), 8 deletions(-)
 create mode 100644 lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BusinessCheckingAccount.java

diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BusinessCheckingAccount.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BusinessCheckingAccount.java
new file mode 100644
index 000000000..eb922f18b
--- /dev/null
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BusinessCheckingAccount.java
@@ -0,0 +1,32 @@
+package com.codedifferently.lesson17.bank;
+
+import java.util.Set;
+
+/** Represents a business checking account */
+public class BusinessCheckingAccount extends CheckingAccount {
+
+  /**
+   * Creates a new business checking account
+   *
+   * @param accountNumber The accounnt number.
+   * @param owners The owners of the account.
+   * @param initialBalance The initial balance of the account.
+   */
+  public BusinessCheckingAccount(
+      String accountNumber, Set<Customer> owners, double initialBalance) {
+    super(accountNumber, owners, initialBalance);
+  }
+
+  @Override
+  public String toString() {
+    return "BusinessCheckingAccount{"
+        + "accountNumber='"
+        + getAccountNumber()
+        + '\''
+        + ", balance="
+        + getBalance()
+        + ", isActive="
+        + isActive()
+        + '}';
+  }
+}
diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Check.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Check.java
index ed813e90d..ff6115984 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Check.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Check.java
@@ -7,7 +7,7 @@ public class Check {
 
   private final String checkNumber;
   private final double amount;
-  private final Account account;
+  private final CheckingAccount account;
   private boolean isVoided = false;
 
   /**
@@ -17,7 +17,7 @@ public class Check {
    * @param amount The amount of the check.
    * @param account The account the check is drawn on.
    */
-  public Check(String checkNumber, double amount, Account account) {
+  public Check(String checkNumber, double amount, CheckingAccount account) {
     if (amount < 0) {
       throw new IllegalArgumentException("Check amount must be positive");
     }
diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
index 62b9716f1..7b4906ff4 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
@@ -19,7 +19,7 @@ public class Customer {
   /**
    * Creates a new customer.
    *
-   * @param id   The ID of the customer.
+   * @param id The ID of the customer.
    * @param name The name of the customer.
    * @param type The type of customer (individual or business)
    */
@@ -32,11 +32,11 @@ public Customer(UUID id, String name, CustomerType type) {
   /**
    * Creates an new individual customer.
    *
-   * @param id   The ID of the customer.
+   * @param id The ID of the customer.
    * @param name The name of the customer.
    * @param type The type of custimer (individual or business)
    */
-  public Customer(UUID id, String name, Customer type) {
+  public Customer(UUID id, String name) {
     this.id = id;
     this.name = name;
     this.type = CustomerType.INDIVIDUAL;
diff --git a/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BankAtmTest.java b/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BankAtmTest.java
index fa4a913a2..9f08e3170 100644
--- a/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BankAtmTest.java
+++ b/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BankAtmTest.java
@@ -43,14 +43,14 @@ void testAddAccount() {
     classUnderTest.addAccount(account3);
 
     // Assert
-    Set<CheckingAccount> accounts = classUnderTest.findAccountsByCustomerId(customer3.getId());
+    Set<Account> accounts = classUnderTest.findAccountsByCustomerId(customer3.getId());
     assertThat(accounts).containsOnly(account3);
   }
 
   @Test
   void testFindAccountsByCustomerId() {
     // Act
-    Set<CheckingAccount> accounts = classUnderTest.findAccountsByCustomerId(customer1.getId());
+    Set<Account> accounts = classUnderTest.findAccountsByCustomerId(customer1.getId());
 
     // Assert
     assertThat(accounts).containsOnly(account1, account2);
diff --git a/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/SavingAccountTest.java b/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/SavingAccountTest.java
index fcf14b237..501a20800 100644
--- a/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/SavingAccountTest.java
+++ b/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/SavingAccountTest.java
@@ -1,3 +1,67 @@
 package com.codedifferently.lesson17.bank;
 
-class CheckingAccountTest {}
+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.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;
+
+class SavingsAccountTest {
+
+  private SavingsAccount account;
+  private Set<Customer> owners;
+
+  @BeforeEach
+  void setUp() {
+    owners = new HashSet<>();
+    owners.add(new Customer(UUID.randomUUID(), "Yuji Nishida"));
+    owners.add(new Customer(UUID.randomUUID(), "Masahiro Sekita"));
+
+    account = new SavingsAccount("123456789", owners, 100.0);
+  }
+
+  @Test
+  void deposit() {
+    account.deposit(100.0);
+    assertEquals(200.0, account.getBalance());
+  }
+
+  @Test
+  void withdraw() {
+    account.withdraw(25.0);
+    assertEquals(75.0, account.getBalance());
+  }
+
+  @Test
+  void withdraw_withNegativeAmount() {
+    assertThatExceptionOfType(IllegalStateException.class)
+        .isThrownBy(() -> account.withdraw(-25.0))
+        .withMessage("Withdrawal amount must be positive");
+  }
+
+  @Test
+  void withdraw_withInsufficientBalance() {
+    assertThatExceptionOfType(InsufficientFundsException.class)
+        .isThrownBy(() -> account.withdraw(200.0))
+        .withMessage("Account does not have enough funds for withdrawal");
+  }
+
+  @Test
+  void closeAccount_withPositiveBalance() {
+    assertThatExceptionOfType(IllegalStateException.class).isThrownBy(() -> account.closeAccount());
+  }
+
+  @Test
+  void isClosed() {
+    assertFalse(account.isClosed());
+    account.withdraw(100.0);
+    account.closeAccount();
+    assertTrue(account.isClosed());
+  }
+}

From 7d5637e8012dd3825d2aeb4e6497ff6261f38e51 Mon Sep 17 00:00:00 2001
From: Evan Philakhong <evanthegamer2004@gmail.com>
Date: Wed, 16 Apr 2025 15:22:31 +0000
Subject: [PATCH 6/7] adds validateBusinessOwners method

adds BusinessCheckingAccount Tests
---
 .../bank/BusinessCheckingAccount.java         | 14 ++++++++++++
 .../lesson17/bank/Customer.java               |  9 ++++++++
 .../bank/BusinessCheckingAccountTest.java     | 22 +++++++++++++++++++
 3 files changed, 45 insertions(+)
 create mode 100644 lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BusinessCheckingAccountTest.java

diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BusinessCheckingAccount.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BusinessCheckingAccount.java
index eb922f18b..5b8a3d688 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BusinessCheckingAccount.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/BusinessCheckingAccount.java
@@ -17,6 +17,20 @@ public BusinessCheckingAccount(
     super(accountNumber, owners, initialBalance);
   }
 
+  /**
+   * Checks if at least one owner is a business.
+   *
+   * @param owners The owers of the account.
+   * @throws IllegalArgumentEception If no business owner is found.
+   */
+  private void validateBusinessOwner(Set<Customer> owners) {
+    boolean hasBusinessOwner = owners.stream().anyMatch(Customer::isBusiness);
+    if (!hasBusinessOwner) {
+      throw new IllegalArgumentException(
+          "Business Checking Account must have at least one business owner");
+    }
+  }
+
   @Override
   public String toString() {
     return "BusinessCheckingAccount{"
diff --git a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
index 7b4906ff4..e3ff7c5af 100644
--- a/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
+++ b/lesson_17/bank/bank_app/src/main/java/com/codedifferently/lesson17/bank/Customer.java
@@ -60,6 +60,15 @@ public Set<Account> getAccounts() {
     return accounts;
   }
 
+  /**
+   * Checks if the owner is a business.
+   *
+   * @return True if the customer is a business, false otherwise.
+   */
+  public boolean isBusiness() {
+    return this.type == CustomerType.BUSINESS;
+  }
+
   @Override
   public int hashCode() {
     return id.hashCode();
diff --git a/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BusinessCheckingAccountTest.java b/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BusinessCheckingAccountTest.java
new file mode 100644
index 000000000..bedd169ad
--- /dev/null
+++ b/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BusinessCheckingAccountTest.java
@@ -0,0 +1,22 @@
+package com.codedifferently.lesson17.bank;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
+
+import org.junit.jupiter.api.Test;
+
+public class BusinessCheckingAccountTest {
+
+  @Test
+  void validateBusinessOwner_withBusinessOwner() {
+    Set<Customer> owners = new HashSet<>();
+    owners.add(new Customer(UUID.randomUUID(), "Elon Musk", CustomerType.BUSINESS));
+    owners.add(new Customer(UUID.randomUUID(), "Elon Musk", CustomerType.BUSINESS));
+
+    BusinessCheckingAccount account = new BusinessCheckingAccount("123456789", owners, 1000.0);
+    assertThat(account).isNotNull();
+  }
+}

From 9e3827628d29a4c035e02f364b4c11aff890c2f5 Mon Sep 17 00:00:00 2001
From: Evan Philakhong <evanthegamer2004@gmail.com>
Date: Wed, 16 Apr 2025 15:31:02 +0000
Subject: [PATCH 7/7] adds BusinessCheckingAccount Tests

---
 .../lesson17/bank/BusinessCheckingAccountTest.java               | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BusinessCheckingAccountTest.java b/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BusinessCheckingAccountTest.java
index bedd169ad..e88be2ed4 100644
--- a/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BusinessCheckingAccountTest.java
+++ b/lesson_17/bank/bank_app/src/test/java/com/codedifferently/lesson17/bank/BusinessCheckingAccountTest.java
@@ -5,7 +5,6 @@
 import java.util.HashSet;
 import java.util.Set;
 import java.util.UUID;
-
 import org.junit.jupiter.api.Test;
 
 public class BusinessCheckingAccountTest {