直到昨天終於寫到 Interface 了
所以就可以利用 Mockery 來寫測試了
所以今天就來重構一下 CartTest 吧

首先先安裝 mockery

composer require mockery/mockery --dev

接下來就來修改 CartTest 吧

// tests/CartTest.php

namespace Recca0120\Cart\Tests;

use Mockery as m;
use Recca0120\Cart\Cart;
use Recca0120\Cart\Item;
use Recca0120\Cart\Store;
use PHPUnit\Framework\TestCase;
use Mockery\Adapter\Phpunit\MockeryPHPUnitIntegration;

class CartTest extends TestCase
{
    use MockeryPHPUnitIntegration;

    /** @test */
    public function 將商品加入購物車並驗證商品有名稱單價數量()
    {
        $item = $this->createItem('商品01', 100, 1);

        $store = m::mock(Store::class);

        $store->shouldReceive('put')->with($item)->once();

        $cart = new Cart($store);
        $cart->put($item);
    }

    /** @test */
    public function 加總()
    {
        $store = m::mock(Store::class);
        $store->shouldReceive('items')->once()->andReturnUsing(function () {
            return [
                $this->createItem('商品01', 100, 2),
                $this->createItem('商品02', 200, 1),
            ];
        });

        $cart = new Cart($store);

        $this->assertEquals(400, $cart->total());
    }

    /** @test */
    public function 移除商品()
    {
        $item = $this->createItem('商品01', 100, 2);

        $store = m::mock(Store::class);
        $store->shouldReceive('remove')->once()->with($item);

        $cart = new Cart($store);

        $cart->remove($item);
    }

    private function createItem($name, $price, $qty)
    {
        return new Item([
            'name' => $name,
            'price' => $price,
            'quantity' => $qty,
        ]);
    }
}