SavingsAccountTest.java

package bankService;

import bankService.exceptions.InsufficientFundsException;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;

import static org.testng.Assert.*;

public class SavingsAccountTest {

    Customer customer;
    SavingsAccount savings;

    @BeforeClass
    public void oneTimeSetup() {
        customer = new Customer ("Mickey Mouse", "Disneyland", "Mickey@disneyland.com");
    }

    @BeforeMethod
    public void eachTimeSetup() {
        savings = new SavingsAccount(customer, 100.00, 123456789);
    }

    /**
     * Customers should be able to withdraw from their savings account.
     * Scenario:
     * 1. Given a customer's savings account with an initial balance of $100.00
     * 2. When I withdraw $60.00 from the account
     * 3. Then the new account balance is $40.00
     */
    @Test(dataProvider ="ValidWithdrawDataProvider")
    public void withdrawingValidAmountFromSavingsAccount_DecreasesBalanceByAmount(double amount, double expectedBalance) throws InsufficientFundsException {
        // When
        savings.withdraw(amount);

        // Then
        assertEquals(savings.getBalance(), expectedBalance);
    }

    @DataProvider(name= "ValidWithdrawDataProvider")
    private Object[][] createValidWithdrawData() {
        return new Object[][] {
                {60.0, 40.0},
                {100.0, 0.0}};
        }

    /**
     *  Customers should not be able to withdraw more than their available savings account balance
     *  Scenario:
     *  1. Given a customer's savings account with an initial balance of $100.00
     *  2. When I attempt to withdraw $200.00
     *  3. Then an exception should occur indicating that there are insufficient funds in the account
     *  4. And the account balance should remain unchanged.
     */
    @Test
    public void withdrawingAmountGreaterThanBalance_Throws_InsufficientFundsException() throws InsufficientFundsException {
        try {
            savings.withdraw(200.00);
            fail("Expected Insufficient Funds Exception but none is thrown");
        } catch (InsufficientFundsException e){
            // Then
            assertEquals(savings.getBalance(), 100.00);
        }
    }
}