Hex renk kodlarını rgba formatına dönüştüren fonksiyon ve testler - Function and tests to convert hex color codes to rgba format

composer.json

{
    "require": {
        "phpunit/phpunit": "^6.2"
    }
}

HexToRgb.php

<?php

/**
 * Converts Hex color values into rgba format.
 *
 * @param string $hex
 * @param mixed  $alpha
 * @return string
 */
function hexToRgb($hex, $alpha = 0)
{
    // remove caret symbol from the start
    $hex = ltrim($hex, '#');

    // if short hex codes used, convert them to full length
    if (strlen($hex) === 3) {
        $hex = extendShortHex($hex);
    }

    validateHexColor($hex);

    // chunk hex value by two digits to get r, g and b values
    $hexArray = str_split($hex, 2);

    $hexArray = array_map(function ($item) {
        return hexdec($item);
    }, $hexArray);

    $hexArray['alpha'] = (float)$alpha;

    return "rgb($hexArray[0], $hexArray[1], $hexArray[2], $hexArray[alpha])";
}

/**
 * Validates hex color values by length and the digits.
 *
 * @param string $hex
 * @throws Error
 */
function validateHexColor($hex)
{
    // hex length validation
    if (strlen($hex) !== 6) {
        throw new Error('Hex code must be 6 digits long.');
    }

    // hex digit validation
    if (ctype_xdigit($hex) === false) {
        throw new Error('Please provide a valid hex number.');
    }
}

/**
 * Short hex codes are converted into six digits.
 *
 * @param string $hex
 * @return string
 */
function extendShortHex($hex)
{
    return $hex[0] . $hex[0] . $hex[1] . $hex[1] . $hex[2] . $hex[2];
}

HexToRgbTest.php

<?php

use PHPUnit\Framework\TestCase;

class HexToRgbTest extends TestCase
{
    /**
     * Tests if a short hex code can be converted into a normal 6 digit hex code.
     */
    public function testShortHexCanBeTurnedIntoLong()
    {
        $this->assertEquals('FFFFFF', extendShortHex('FFF'));
        $this->assertEquals('FF7700', extendShortHex('F70'));
    }

    /**
     * Tests that an error must be thrown if hex code has invalid number of characters.
     */
    public function testHexLengthValidation()
    {
        $this->expectException(Error::class);
        hexToRgb('FFFFF', 1);
    }

    /**
     * Tests if hex color code has digits that are not in hexadecimal system.
     */
    public function testHexValidation()
    {
        $this->expectException(Error::class);
        hexToRgb('FFFFFG');
    }

    /**
     * Tests a hex color code can be converted to rgba format as string.
     */
    public function testHexCanBeConvertedToRgb()
    {
        $this->assertEquals('rgb(255, 255, 255, 0.3)', hexToRgb('#FFF', '0.3'));
        $this->assertEquals('rgb(255, 255, 255, 1)', hexToRgb('#FFFFFF', 1));
        $this->assertEquals('rgb(255, 255, 255, 0.5)', hexToRgb('FFF', '.5'));
        $this->assertEquals('rgb(255, 255, 255, 1)', hexToRgb('FFFFFF', 1));
    }
}

phpunit.xml

<?xml version="1.0" encoding="UTF-8"?>
<phpunit colors="true" bootstrap="HexToRgb.php">
    <testsuites>
        <testsuite name="Hex to RGB Tests">
            <directory>./HexToRgbTest.php</directory>
        </testsuite>
    </testsuites>
</phpunit>