What is the difference between overload and alias in Mockery?

Question

I am new to using Mockery and confused with the terminology alias and overload. Can anyone please explain to me when to use which?

Answer 1

Overload is used to create an "instance mock". This will "intercept" when a new instance of a class is created and the mock will be used instead. For example if this code is to be tested:

class ClassToTest {

    public function methodToTest()
    {
        $myClass = new MyClass();
        $result = $myClass->someMethod();
        return $result;
    }
}

You would create an instance mock using overload and define the expectations like this:

 public function testMethodToTest()
 {
     $mock = Mockery::mock('overload:MyClass');
     $mock->shouldreceive('someMethod')->andReturn('someResult');

     $classToTest = new ClassToTest();
     $result = $classToTest->methodToTest();

     $this->assertEquals('someResult', $result);
 }

Alias is used to mock public static methods. For example if this code is to be tested:

class ClassToTest {

    public function methodToTest()
    {
        return MyClass::someStaticMethod();
    }
}

You would create an alias mock using alias and define the expectations like this:

public function testNewMethodToTest()
{
    $mock = Mockery::mock('alias:MyClass');
    $mock->shouldreceive('someStaticMethod')->andReturn('someResult');

    $classToTest = new ClassToTest();
    $result = $classToTest->methodToTest();

    $this->assertEquals('someResult', $result);
}