PHPUnit mocked method returns null - php

Question

I am trying to test the below class using PHPUnit
class stripe extends paymentValidator {
public $apiKey;
public function __construct ($apiKey){
$this->apiKey = $apiKey;
}
public function charge($token) {
try {
return $this->requestStripe($token);
} catch(\Stripe\Error\Card $e) {
echo $e->getMessage();
return false;
}
}
public function requestStripe($token) {
// do something
}
}
My test scripts is like the below:
class paymentvalidatorTest extends PHPUnit_Framework_TestCase
{
/**
* #test
*/
public function test_stripe() {
// Create a stub for the SomeClass class.
$stripe = $this->getMockBuilder(stripe::class)
->disableOriginalConstructor()
->setMethods(['requestStripe', 'charge'])
->getMock();
$stripe->expects($this->any())
->method('requestStripe')
->will($this->returnValue('Miaw'));
$sound = $stripe->charge('token');
$this->assertEquals('Miaw', $sound);
}
}
With my test script I was expecting the test double of stripe::charge() method will do exactly as the defined in the original class and the stripe::requestStripe() will return 'Miaw'. Therefore, $stripe->charge('token') should also return 'Miaw'. However, when I run the test I get:
Failed asserting that null matches expected 'Miaw'.
How should I fix this ?

Answer 1

Where you're calling setMethods, you're telling PHPUnit that the mock class should mock the behaviour of those methods:
->setMethods(['requestStripe', 'charge'])
In your case it looks like you want to partially mock the class, so that requestStripe() returns Miaw, but you want charge to run its original code - you should just remove charge from the mocked methods:
$stripe = $this->getMockBuilder(stripe::class)
->disableOriginalConstructor()
->setMethods(['requestStripe'])
->getMock();
$stripe->expects($this->once())
->method('requestStripe')
->will($this->returnValue('Miaw'));
$sound = $stripe->charge('token');
$this->assertEquals('Miaw', $sound);
While you're at it you may as well specify how many times you expect requestStripe() to be called - it's an extra assertion with no extra effort, as using $this->any() doesn't provide you with any added benefit. I've included using $this->once() in the example.