Humbug\PhpScoper\RegexChecker

Complexity

Total Complexity

11

Size/Duplication

Total Lines	70
Duplicated Lines	0 %

Importance

Changes	1
Bugs	0	Features	0

3 Methods

Rating	Name	Duplication	Size	Complexity
A	validateRegex()	0	10	2
A	isRegexLike()	0	23	5
A	isValidRegexFlags()	0	15	4

<?php

declare(strict_types=1);

namespace Humbug\PhpScoper;

use function array_pop;
use function count;
use function current;
use function end;
use function explode;
use function in_array;
use function preg_last_error;
use function preg_last_error_msg;
use function preg_match as native_preg_match;
use function Safe\sprintf;
use function str_contains;
use function str_split;
use function strlen;
use function trim;

// TODO: move this under a Configuration namespace
final class RegexChecker
{
    // https://www.php.net/manual/en/reference.pcre.pattern.modifiers.php
    private const PATTERN_MODIFIERS = [
        'i',
        'm',
        's',
        'x',
        'A',
        'D',
        'S',
        'U',
        'X',
        'J',
        'u',
    ];

    public function isRegexLike(string $value): bool
    {
        $valueLength = strlen($value);

        if ($valueLength < 2) {
            return false;
        }

        $firstCharacter = $value[0];

        $parts = explode($firstCharacter, $value);

        if (false === $parts || count($parts) !== 3) {
            return false;
        }

        $lastPart = array_pop($parts);

        if (!self::isValidRegexFlags($lastPart)) {
            return false;
        }

        return true;
    }

    public function validateRegex(string $regex): ?string
    {
        if (@native_preg_match($regex, '') !== false) {
            return null;
        }

        return sprintf(
            'Invalid regex: %s (code %s)',
            preg_last_error_msg(),
            preg_last_error(),
        );
    }

    private static function isValidRegexFlags(string $value): bool
    {
        if ('' === $value) {
            return true;
        }

        $characters = str_split($value);

        foreach ($characters as $character) {
            if (!in_array($character, self::PATTERN_MODIFIERS, true)) {
                return false;
            }
        }

        return true;
    }
}