Dealing with protected/private methods or properties

In a perfect world, we should not be digging into protected or private methods or properties in our unit tests. That's a bad test smell! However, there are some times when I've found this useful. And for that, I use two different methods that I put in my bootstrap.php file that PHPUnit loads.

First, let's say you want to get a property from a class in a test:

class Mine
{
  protected $about = '';

  public function __construct()
  {
    $this->about = 'me';
  }
}

And we want to test the about property. Again, we probably don't need or want to do this - but just in case, you could do something like this:

public function testItsAllAboutMe(): void
{
  $mine = new Mine();
  $this->assertEquals('me', getProperty($mine, 'about'));
}

Now, what is getProperty():

function getProperty($object, $propertyName)
{
  $reflection = new \ReflectionClass($object);
  $property = $reflection->getProperty($propertyName);
  $property->setAccessible(true);
  return $property->getValue($object);
}

This works by creating a reflection class of the method, altering the property visibility and then returning the value.

What about if you want to call a method?

function callMethod($object, $methodName, array $arguments = [])
{
  $class = new \ReflectionClass($object);
  $method = $class->getMethod($methodName);
  $method->setAccessible(true);
  return empty($arguments) ? $method->invoke($object) : $method->invokeArgs($object, $arguments);
}

There you go.

I feel like I have to say it again - you probably don't want to use this, but in the very few rare times that you can't mock out something - or setting up a test scenario with only public access is too verbose, tiring or expensive, you can access protected or private elements this way.

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Oh and I have an archived package called package-for-laravel/testing-framework - that you can check out for how I implemented this in my own projects - as well as some other useful nuggets.