PHPUnit: Mocking __get() results in "__get() must take exactly 1 argument ..." - php

Question

I've got a problem with mocking an overloaded __get($index) method.
The code for the class to be mocked and the system under test that consumes it is as follows:
<?php
class ToBeMocked
{
protected $vars = array();
public function __get($index)
{
if (isset($this->vars[$index])) {
return $this->vars[$index];
} else {
return NULL;
}
}
}
class SUTclass
{
protected $mocky;
public function __construct(ToBeMocked $mocky)
{
$this->mocky = $mocky;
}
public function getSnack()
{
return $this->mocky->snack;
}
}
Test looks as follows:
<?php
class GetSnackTest extends PHPUnit_Framework_TestCase
{
protected $stub;
protected $sut;
public function setUp()
{
$mock = $this->getMockBuilder('ToBeMocked')
->setMethods(array('__get')
->getMock();
$sut = new SUTclass($mock);
}
/**
* #test
*/
public function shouldReturnSnickers()
{
$this->mock->expects($this->once())
->method('__get')
->will($this->returnValue('snickers');
$this->assertEquals('snickers', $this->sut->getSnack());
}
}
Real code is a little bit more complex, though not much, having "getSnacks()" in its parent class. But this example should suffice.
Problem is I get the following error, when executing the test with PHPUnit:
Fatal error: Method Mock_ToBeMocked_12345672f::__get() must take exactly 1 argument in /usr/share/php/PHPUnit/Framework/MockObject/Generator.php(231)
When I debug I can't even reach the test method. It seems it breaks at setting up the mock object.
Any ideas?

Answer 1

__get() takes an argument, so you need to provide the mock with one:
/**
* #test
*/
public function shouldReturnSnickers()
{
$this->mock->expects($this->once())
->method('__get')
->with($this->equalTo('snack'))
->will($this->returnValue('snickers'));
$this->assertEquals('snickers', $this->sut->getSnack());
}
The with() method sets the argument for the mocked method in PHPUnit. You can find more details in the section on Test Doubles.

Answer 2

It's a bit hidden in the comments, but #dfmuir's answer put me on the right track. Mocking a __get method is straight forward if you use a callback.
$mock
->method('__get')
->willReturnCallback(function ($propertyName) {
switch($propertyName) {
case 'id':
return 123123123123;
case 'name':
return 'Bob';
case 'email':
return 'bob#bob.com';
}
}
);
$this->assertEquals('bob#bob.com', $mock->email);

Answer 3

Look in the mocked magic method __get. Probably you call there one more __get method from another and not properly mocked object.

Answer 4

What you are doing in the setUp method of your GetSnackTest class is incorrect.
If you want the code of the __get method to be executed (which would be the point of your test> I suppose), you have to change the way you call setMethods in the setup method.
Here's the complete explanation, but here's the relevant part:
Passing an array containing method names
The methods you have identified:
Are all stubs,
All return null by default,
Are easily overridable
So, you need to call setMethods by passing null, or by passing an array that contains some methods (the ones that you really want to stub), but not- __get (because you actually want the code of that method to be executed).
The, in the shouldReturnSnickers method, you will simply want to want to call $this->assertEquals('snickers', $this->sut->getSnack());, without the preceding lines with the expect part.
This will ensure the code of your __get method is actually executed and tested.

Answer 5

withAnyParameters() method can help you, this works correct:
$this->mock -> expects($this -> once())
-> method('__get') -> withAnyParameters()
-> will($this -> returnValue('snikers'));