Best practices to test protected methods with PHPUnit

Question

I found the discussion on Do you test private method informative.

I have decided, that in some classes, I want to have protected methods, but test them. Some of these methods are static and short. Because most of the public methods make use of them, I will probably be able to safely remove the tests later. But for starting with a TDD approach and avoid debugging, I really want to test them.

I thought of the following:

• Method Object as adviced in an answer seems to be overkill for this.
• Start with public methods and when code coverage is given by higher level tests, turn them protected and remove the tests.
• Inherit a class with a testable interface making protected methods public

Which is best practice? Is there anything else?

It seems, that JUnit automatically changes protected methods to be public, but I did not have a deeper look at it. PHP does not allow this via reflection.

Answer 1

If you're using PHP5 (>= 5.3.2) with PHPUnit, you can test your private and protected methods by using reflection to set them to be public prior to running your tests:

protected static function getMethod($name) {
  $class = new ReflectionClass('MyClass');
  $method = $class->getMethod($name);
  // $method->setAccessible(true); // Use this if you are running PHP older than 8.1.0
  return $method;
}

public function testFoo() {
  $foo = self::getMethod('foo');
  $obj = new MyClass();
  $foo->invokeArgs($obj, array(...));
  ...
}