/**
 * @var Vimes|ObjectProphecy
 */
 private $vimes;

<?php

use PHPUnit\Framework\TestCase;
use Prophecy\Prophecy\ObjectProphecy;
use Zalas\PHPUnit\Doubles\TestCase\ProphecyTestDoubles;

class DiscworldTest extends TestCase
{
    use ProphecyTestDoubles;

    /**
     * @var Vimes|ObjectProphecy
     */
    private $vimes;

    /**
     * @var Nobby|Fred|ObjectProphecy
     */
    private $nobbyAndFred;

    public function test_it_hires_new_recruits_for_nightwatch()
    {
        $discworld = new Discworld($this->vimes->reveal(), $this->nobbyAndFred->reveal());

        $discworld->createNightWatch();

        $this->vimes->recruit($this->nobbyAndFred)->shouldHaveBeenCalled();
    }
}

<?php

use PHPUnit\Framework\MockObject\MockObject;
use PHPUnit\Framework\TestCase;
use Zalas\PHPUnit\Doubles\TestCase\PHPUnitTestDoubles;

class DiscworldTest extends TestCase
{
    use PHPUnitTestDoubles;

    /**
     * @var Vimes|MockObject
     */
    private $vimes;

    /**
     * @var Nobby|MockObject
     */
    private $nobbyAndFred;

    public function test_it_hires_new_recruits_for_nightwatch()
    {
        $discworld = new Discworld($this->vimes, $this->nobby);

        $this->vimes->expects($this->once())
            ->method('recruit')
            ->with($this->nobby);

        $discworld->createNightWatch();
    }
}