BankAccount.php

BankAccount.php

<?php
class BankAccount {
    /** @var int */
    protected $_balance;

    function __construct()
    {
        $this->_balance = 0;
    }

    public function getBalance()
    {
        return $this->_balance;
    }

    public function deposit($amount)
    {
        if ($amount <= 0) {
            throw new Exception("Amount has to be > 0.");
        }
        if ($amount > 100000) {
            throw new Exception("Amounts over 100.000 have to be verified.");
        }

        $this->_balance += $amount;
    }

    public function withdraw($amount)
    {
        if ($amount <= 0) {
            throw new Exception("Amount has to be > 0.");
        }

        $this->_balance -= $amount;
    }
}

BankAccountTest.php

<?php
require_once 'BankAccount.php';

class BankAccountTest extends PHPUnit_Framework_TestCase {
    /** @var BankAccount */
    protected $_account;

    protected function setUp()
    {
        $this->_account = new BankAccount();
    }

    public function testBalanceIsZeroWhenOpeningAccount() {
        $this->assertEquals(0, $this->_account->getBalance());
    }

    public function testDepositIncreasesBalance() {
        $this->_account->deposit(100);
        $this->assertEquals(100, $this->_account->getBalance());
    }

    public function testWithdrawDecreasesBalance() {
        $this->_account->withdraw(100);
        $this->assertEquals(-100, $this->_account->getBalance());
    }

    /**
     * @expectedException Exception
     */
    public function testDepositNegativeAmountThrowsException() {
        $this->_account->deposit(-200);
    }
}