phpunit - mockbuilder - set mock object internal property - php

Question

Is it possible to create a mock object with disabled constructor and manually setted protected properties?
Here is an idiotic example:
class A {
protected $p;
public function __construct(){
$this->p = 1;
}
public function blah(){
if ($this->p == 2)
throw Exception();
}
}
class ATest extend bla_TestCase {
/**
#expectedException Exception
*/
public function testBlahShouldThrowExceptionBy2PValue(){
$mockA = $this->getMockBuilder('A')
->disableOriginalConstructor()
->getMock();
$mockA->p=2; //this won't work because p is protected, how to inject the p value?
$mockA->blah();
}
}
So I wanna inject the p value which is protected, so I can't. Should I define setter or IoC, or I can do this with phpunit?

Answer 1

You can make the property public by using Reflection, and then set the desired value:
$a = new A;
$reflection = new ReflectionClass($a);
$reflection_property = $reflection->getProperty('p');
$reflection_property->setAccessible(true);
$reflection_property->setValue($a, 2);
Anyway in your example you don't need to set p value for the Exception to be raised. You are using a mock for being able to take control over the object behaviour, without taking into account it's internals.
So, instead of setting p = 2 so an Exception is raised, you configure the mock to raise an Exception when the blah method is called:
$mockA = $this->getMockBuilder('A')
->disableOriginalConstructor()
->getMock();
$mockA->expects($this->any())
->method('blah')
->will($this->throwException(new Exception));
Last, it's strange that you're mocking the A class in the ATest. You usually mock the dependencies needed by the object you're testing.
Hope this helps.

Answer 2

Thought i'd leave a handy helper method that could be quickly copy and pasted here:
/**
* Sets a protected property on a given object via reflection
*
* #param $object - instance in which protected value is being modified
* #param $property - property on instance being modified
* #param $value - new value of the property being modified
*
* #return void
*/
public function setProtectedProperty($object, $property, $value)
{
$reflection = new ReflectionClass($object);
$reflection_property = $reflection->getProperty($property);
$reflection_property->setAccessible(true);
$reflection_property->setValue($object, $value);
}

Answer 3

Based on the accepted answer from #gontrollez, since we are using a mock builder we do not have the need to call new A; since we can use the class name instead.
$a = $this->getMockBuilder(A::class)
->disableOriginalConstructor()
->getMock();
$reflection = new ReflectionClass(A::class);
$reflection_property = $reflection->getProperty('p');
$reflection_property->setAccessible(true);
$reflection_property->setValue($a, 2);

Answer 4

Based on #rsahai91 answer above, created a new helper for making multiple methods accessible. Can be private or protected
/**
* Makes any properties (private/protected etc) accessible on a given object via reflection
*
* #param $object - instance in which properties are being modified
* #param array $properties - associative array ['propertyName' => 'propertyValue']
* #return void
* #throws ReflectionException
*/
public function setProperties($object, $properties)
{
$reflection = new ReflectionClass($object);
foreach ($properties as $name => $value) {
$reflection_property = $reflection->getProperty($name);
$reflection_property->setAccessible(true);
$reflection_property->setValue($object, $value);
}
}
Example use:
$mock = $this->createMock(MyClass::class);
$this->setProperties($mock, [
'propname1' => 'valueOfPrivateProp1',
'propname2' => 'valueOfPrivateProp2'
]);

Answer 5

It would be amazing if every codebase used DI and IoC, and never did stuff like this:
public function __construct(BlahClass $blah)
{
$this->protectedProperty = new FooClass($blah);
}
You can use a mock BlahClass in the constructor, sure, but then the constructor sets a protected property to something you CAN'T mock.
So you're probably thinking "Well refactor the constructor to take a FooClass instead of a BlahClass, then you don't have to instantiate the FooClass in the constructor, and you can put in a mock instead!" Well, you'd be right, if that didn't mean you would have to change every usage of the class in the entire codebase to give it a FooClass instead of a BlahClass.
Not every codebase is perfect, and sometimes you just need to get stuff done. And that means, yes, sometimes you need to break the "only test public APIs" rule.

Answer 6

You may want to use the ReflectionProperty as well.
$reflection = new ReflectionProperty(Foo::class, 'myProperty');
$reflection->setAccessible(true); // Do this if less than PHP8.1.
$reflection->setValue($yourMock, 'theValue');