How to unit test while loop in PHPUnit? - php

Question

I have a Service class and a test for that, follow below:
Class
class MyCustomService
{
public function job()
{
while($this->getResponseFromThirdPartyApi()->data) {
// do some stuff...
}
return ...
}
protected function getResponseFromThirdPartyApi()
{
// Here do some curl and return stdClass
// data attribute is populated only on first curl request
}
}
Test mocking getResponseFromThirdPartyApi method
class MyCustomServiceTest
{
public function testJobImportingData()
{
$myCustomServiceMock = $this->getMockBuilder('MyCustomService')
->setMethods(array('getResponseFromThirdPartyApi'))
->getMock();
$myCustomServiceMock->expects($this->any())
->method('getResponseFromThirdPartyApi')
->willReturn($this->getResponseWithData());
$jobResult = $myCustomServiceMock->job();
// here some assertions on $jobResult
}
protected function getResponseWithData()
{
$response = new \stdClass;
$response->data = ['foo', 'bar'];
return $response;
}
}
How can I change getResponseWithData return after first call on MyCustomService while loop?
I've tried creating a custom flag on MyCustomServiceTest and checking on getResponseWithData, but fails once that mocked object doesn't call getResponseWithData method again on MyCustomServiceTest.
Any direction?

Answer 1

As Nico Haase suggested above, the path is to use callback.
After some research I achieved passing mock object reference to method mocked and checking flag, this results on:
class MyCustomServiceTest
{
public function testJobImportingData()
{
$myCustomServiceMock = $this->getMockBuilder('MyCustomService')
->setMethods(array('getResponseFromThirdPartyApi'))
->getMock();
$myCustomServiceMock->expects($this->any())
->method('getResponseFromThirdPartyApi')
->will($this->returnCallback(
function () use ($myCustomServiceMock) {
return $this->getResponseWithData($myCustomServiceMock)
}
));
$jobResult = $myCustomServiceMock->job();
// here some assertions on $jobResult
}
protected function getResponseWithData(&$myCustomServiceMock)
{
$response = new \stdClass;
if (isset($myCustomServiceMock->imported)) {
$response->data = false;
return $response;
}
$myCustomServiceMock->imported = true;
$response = new \stdClass;
$response->data = ['foo', 'bar'];
return $response;
}
}
Then while loop will be called only once and we be able to test without forever loop.