dependency-injection-as-a-tool-for-testing-fake.php

<?php

class FakeBar
{
    public $users = [
        1 => [
            'name' => 'Adam',
            'email' => 'adam@example.com'
        ]
    ];

    public function editAndReturnUser($id, $name, $email)
    {
        $this->users[$id]['name'] = $name;
        $this->users[$id]['email'] = $email;

        return $this->users[$id];
    }
}

class TestFoo extends PHPUnit_Framework_Testcase
{
    public function testDoSomethingEditsDataAndReturnsArray()
    {
        $foo = new Foo;
        $fakeBar = new FakeBar;

        $user = $foo->doSomething($fakeBar, 1, 'Phil', 'hello@example.com');

        $this->assertInternalType('array', $user, 'The return of (doSomething) was not an array');
        $this->assertSame($user['name'], 'Phil', 'The returned user name was not as expected');
        $this->assertSame($user['email'], 'hello@example.com', 'The returned user email was not as expected');
        // verify that the state of FakeBar has changed
        $this->assertSame($fakeBar->users['name'], 'Phil', 'The user name in FakeBar was not changed');
        $this->assertSame($fakeBar->users['email'], 'hello@example.com');
    }
}