Cata: Count of Positives / Sum of Negatives

countpositivessumnegatives.php

<?php
/**
 * Unit tests for "Count of Positives / Sum of Negatives" puzzle
 *
 * Requirements: @see https://www.codewars.com/kata/count-of-positives-slash-sum-of-negatives/php
 * Given an array of integers.
 * Return an array, where the first element is the count of positives numbers
 * and the second element is sum of negative numbers.
 *
 * If the input array is empty or null, return an empty array.
 *
 * @package Cata\Tests\Unit\CountPosSumNeg
 * @author  Caspar Green <[email protected]>
 * @since   1.0.0
 */
declare(strict_types=1);

namespace Cata\Tests\Unit\CountPosSumNeg;

use Cata\CountPosSumNeg\CounterSummer;
use PHPUnit\Framework\TestCase;

class CounterSummerTest extends TestCase
{
    /**
     * A CountSummer instance.
     *
     * @var CounterSummer
     */
    private $countSum;

    /**
     * Sample input.
     *
     * @var array
     */
    private $sampleInput;

    /**
     * Set up each test.
     *
     * @since 1.0.0
     *
     * @return void
     */
    protected function setUp()
    {
        $this->countSum    = new CounterSummer();
        $this->sampleInput = [1, -4, 0, 3, -8, 5, 0, -25, 7, -7];
    }

    /**
     * Test main() should return an empty array when input array is empty or null.
     *
     * @since 1.0.0
     *
     * @return void
     */
    public function testMainShouldReturnEmptyArrayWhenInputEmptyOrNull(): void
    {
        // Test null case.
        $result1 = $this->countSum->main();
        $this->assertIsArray($result1);
        $this->assertEmpty($result1);

        // Test empty array case.
        $result2 = $this->countSum->main([]);
        $this->assertIsArray($result2);
        $this->assertEmpty($result2);
    }

    /**
     * Test main() should return the count of positives in the first item of an array.
     *
     * @since 1.0.0
     *
     * @return void
     */
    public function testMainShouldReturnCountOfPositivesInFirstArrayItem(): void
    {
        $result = $this->countSum->main($this->sampleInput);

        $this->assertEquals(4, $result[0]);
    }

    /**
     * Test main() should return the sum of negatives in the second item of an array.
     *
     * @since 1.0.0
     *
     * @return void
     */
    public function testMainShouldReturnSumOfNegativesInSecondArrayItem(): void
    {
        $result = $this->countSum->main($this->sampleInput);

        $this->assertEquals(-44, $result[1]);
    }
}

<?php
/**
 * Count of Positives / Sum of Negatives
 *
 * @package Cata\CountPosSumNeg
 * @author  Caspar Green <[email protected]>
 * @since   1.0.0
 */
declare(strict_types=1);

namespace Cata\CountPosSumNeg;


/**
 * Class CounterSummer
 *
 * @package Cata\CountPosSumNeg
 * @since   1.0.0
 */
class CounterSummer
{
    /**
     * Count the positives and sum the negatives.
     *
     * @param array $input
     *
     * @since 1.0.0
     *
     * @return array
     */
    public function main(array $input = []): array
    {
        if (empty($input)) {
            return [];
        }

        $count = 0;
        $sum   = 0;

        foreach ($input as $item) {
            ($item <= 0)
                ? $sum += $item
                : $count++;
        }

        return [$count, $sum];
    }
}