Refactoring static usage

static-mockable.php

class Foo {
    public function addAndSquare($bar, $baz) {
        $tmp = $this->add($bar, $baz);
        return $this->multiply($tmp, $tmp);
    }

    protected function add($foo, $bar) {
        return Calculator::add($foo, $bar);
    }

    protected function multiply($foo, $bar) {
        return Calculator::multiply($foo, $bar);
    }
}

class FooTest
extends PHPUnit_Framework_TestCase {
    public function testAddAndSquare() {
        $mockFoo = $this->getMock('Foo',
            array('add', 'multiply'));
        $mockFoo->expects($this->any())
            ->method('add')
            ->will($this->returnValue(42));
        $mockFoo->expects($this->any())
            ->method('multiply')
            ->with($this->equalTo(42),
                $this->equalTo(42))
            ->will($this->returnValue(99));
        $this->assertEquals(99,
            $mockFoo->addAndSquare(1, 1));
    }
}