Feat: BankATM & BankAtmTest

Author: Yafiaha

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

@@ -18,13 +18,21 @@ public class BankAtm {
    * @param account The account to add.
    */
   public void addAccount(CheckingAccount account) {
+    if (account instanceof BusinessCheckingAccount) {
+      Set<Customer> owners = account.getOwners();
+
+      // Ensure at least one owner is a business
+      if (owners.stream().noneMatch(Customer::isBusiness)) {
+        throw new IllegalArgumentException(
+            "A BusinessCheckingAccount must have at least one business owner.");
+      }
+    }
+
+    // Add the account to accountByNumber
     accountByNumber.put(account.getAccountNumber(), account);
-    account
-        .getOwners()
-        .forEach(
-            owner -> {
-              customerById.put(owner.getId(), owner);
-            });
+
+    // Add each owner to customerById
+    account.getOwners().forEach(owner -> customerById.put(owner.getId(), owner));
   }
 
   /**

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

@@ -107,4 +107,31 @@ void testWithdrawFunds_AccountNotFound() {
         .isThrownBy(() -> classUnderTest.withdrawFunds(nonExistingAccountNumber, 50.0))
         .withMessage("Account not found");
   }
+
+  @Test
+  void testAddBusinessCheckingAccount_WithBusinessOwner() {
+    // Arrange
+    Customer businessCustomer = new Customer(UUID.randomUUID(), "TechCorp", CustomerType.BUSINESS);
+    Set<Customer> owners = Set.of(businessCustomer);
+
+    // Act
+    BusinessCheckingAccount businessAccount =
+        new BusinessCheckingAccount("BUS123456", owners, 500.0);
+
+    // Assert
+    assertThat(businessAccount.getOwners()).contains(businessCustomer);
+  }
+
+  @Test
+  void testAddBusinessCheckingAccount_WithoutBusinessOwner() {
+    // Arrange
+    Customer individualCustomer =
+        new Customer(UUID.randomUUID(), "John Doe", CustomerType.INDIVIDUAL);
+    Set<Customer> owners = Set.of(individualCustomer);
+
+    // Act & Assert
+    assertThatExceptionOfType(IllegalArgumentException.class)
+        .isThrownBy(() -> new BusinessCheckingAccount("BUS987654", owners, 1000.0))
+        .withMessage("A BusinessCheckingAccount must have at least one business owner.");
+  }
 }