Array Product puzzle

arrayproduct.php

<?php
/**
 * Unit tests for Product of Array Items puzzle.
 *
 * @see    https://www.codewars.com/kata/product-of-array-items/
 *
 * Requirements: Calculate the product of all elements in an array.
 * If the array is NULL or empty, return NULL
 *
 * @author Caspar Green <caspar@iCasparWebDevelopment.com>
 * @since  1.0.0
 */
declare(strict_types=1);

namespace Cata\Tests\Unit\ArrayPuzzles;

use Cata\ArrayPuzzles\ArrayProducts;
use PHPUnit\Framework\TestCase;

class ArrayProductsTest extends TestCase
{

    /**
     * Test getArrayProduct() should return null when the array is empty of null.
     *
     * @since 1.0.0
     *
     * @return void
     */
    public function testGetArrayProductShouldReturnNullWhenArrayEmptyOrNull(): void
    {
        $arrayProduct = new ArrayProducts();

        $this->assertNull($arrayProduct->getArrayProduct(null));
        $this->assertNull($arrayProduct->getArrayProduct([]));
    }

    public function testGetArrayProductShouldReturnArrayProductWhenArray(): void
    {

        $arrayProduct = new ArrayProducts();

        $this->assertEquals(0, $arrayProduct->getArrayProduct([1, 4, 6, 0]));
        $this->assertEquals(48, $arrayProduct->getArrayProduct([1, 4, 6, 2]));
        $this->assertEquals(-250, $arrayProduct->getArrayProduct([-1, 5, 5, 10]));
    }
}

<?php
/**
 * Product of Array Items puzzle.
 *
 * @package Cata\ArrayPuzzles
 * @author  Caspar Green <caspar@iCasparWebDevelopment.com>
 * @since   1.0.0
 */
declare(strict_types=1);

namespace Cata\ArrayPuzzles;

/**
 * Class ArrayProducts
 *
 * @package Cata\ArrayPuzzles
 * @since   1.0.0
 */
class ArrayProducts
{
    /**
     * Get the array product.
     *
     * @param array|null $array
     *
     * @since 1.0.0
     *
     * @return int|null
     */
    public function getArrayProduct(?array $array): ?int
    {
        if (empty($array)) {
            return null;
        }

        $product = 1;

        foreach ($array as $item) {
            $product *= $item;
        }

        return $product;
    }

//    OR the built-in way
//    public function getArrayProductShort(?array $array): ?int
//    {
//        return (empty($array)) ? null : array_product($array);
//    }
}