How to test an abstract class in PHPUnit?

@daisha.padberg To test an abstract class in PHPUnit, you can create a concrete subclass of the abstract class and run your tests on the subclass. In your tests, you can use mock objects to simulate the behavior of the abstract methods, if necessary. Here is an example of how you might do this:

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// Define the abstract class
abstract class AbstractClass
{
  abstract public function abstractMethod();

  public function concreteMethod()
  {
    // Do something here
  }
}

// Create a concrete subclass of the abstract class
class ConcreteClass extends AbstractClass
{
  public function abstractMethod()
  {
    // Implement the abstract method here
  }
}

// Define your tests
class AbstractClassTest extends PHPUnit_Framework_TestCase
{
  public function testConcreteMethod()
  {
    // Create an instance of the concrete subclass
    $class = new ConcreteClass();

    // Call the concrete method and assert the result
    $this->assertEquals('expected result', $class->concreteMethod());
  }

  public function testAbstractMethod()
  {
    // Create a mock object of the abstract class
    $mock = $this->getMockForAbstractClass('AbstractClass');

    // Configure the mock object to return a specific value when the
    // abstract method is called
    $mock->expects($this->any())
      ->method('abstractMethod')
      ->will($this->returnValue('mock result'));

    // Call the abstract method on the mock object and assert the result
    $this->assertEquals('mock result', $mock->abstractMethod());
  }
}

@daisha.padberg 

In this example:

1. We define an abstract class called AbstractClass with an abstract method abstractMethod() and a concrete method concreteMethod().
2. We create a concrete subclass called ConcreteClass that extends AbstractClass and implements the abstract method abstractMethod().
3. We define a test class called AbstractClassTest that extends PHPUnit_Framework_TestCase.
4. In the testConcreteMethod() test method, we create an instance of ConcreteClass and call the concrete method concreteMethod(). We then assert the result of the method call.
5. In the testAbstractMethod() test method, we create a mock object of the abstract class using the getMockForAbstractClass() method provided by PHPUnit. We configure the mock object to return a specific value when the abstract method abstractMethod() is called. We then call the abstract method on the mock object and assert the result.

By creating a concrete subclass and using mock objects, we can test the behavior of the abstract class and its methods in isolation, without needing to instantiate the abstract class directly.