How to mock objects and methods in PHPUnit tests?

In PHPUnit, you can mock objects and methods using the built-in getMock() and getMockBuilder() methods. These methods allow you to create mock objects that simulate the behavior of real objects or methods.

Here is a step-by-step guide on how to mock objects and methods in PHPUnit:

First, create an instance of the PHPUnit_Framework_TestCase class or extend it in your test class.
To mock an object, use the getMock() method, passing the name of the class or interface you want to mock as the first argument. For example:

$mockObject = $this->getMock('YourClassName');

Optionally, you can specify a list of methods to mock using the second parameter of getMock(). This is an array of method names that you want to mock. If you do not specify any methods, all methods of the object will be mocked. For example:

$mockObject = $this->getMock('YourClassName', ['method1', 'method2']);

To mock a method of an object, use the getMockBuilder() method, passing the name of the class or interface containing the method as the argument. Then, use the setMethods() method to specify which method(s) to mock. For example:

$mockBuilder = $this->getMockBuilder('YourClassName');
$mockBuilder->setMethods(['method1', 'method2']);
$mockObject = $mockBuilder->getMock();

Once you have created the mock object, you can define the behavior of the mocked methods using the expects() and willReturn() methods. For example:

$mockObject->expects($this->once())
    ->method('method1')
    ->willReturn('mocked value');

This code snippet defines that the method1 should be called only once and it should return the value 'mocked value'.

Finally, use the mock object in your tests to verify that the expected behavior occurs.

These are the basic steps to mock objects and methods in PHPUnit tests. There are many more advanced features and options available for mocking using PHPUnit, such as specifying arguments, returning different values based on arguments, verifying method invocations, etc. The PHPUnit documentation provides detailed information on these advanced mocking features.