MockingABusinessObject.php

<?

class PaymentTest extends TestCase
{
    public function testProcessPaymentReturnsTrueOnSuccessfulPayment()
    {
        $paymentDetails = array(
            'amount'   => 123.99,
            'card_num' => '4111-1111-1111-1111',
            'exp_date' => '03/2013',
        );     

        $payment = $this->getMockBuilder('Payment')
            ->setConstructorArgs(array())
            ->getMock();
        // You should not mock a business object!

        $authorizeNet = new AuthorizeNetAIM(
            $payment::API_ID, $payment::TRANS_KEY);
        // This is an external and coupled system.
        // You have no control over it so tests become fragile
        $paymentProcessResult = $payment->processPayment(
            $authorizeNet, $paymentDetails);
        $this->assertTrue($paymentProcessResult);
    }
}