Tester\Assert::expandMatchingPatterns PHP Method

    public static function expandMatchingPatterns($pattern, $actual)
    {
        if (self::isPcre($pattern)) {
            return [$pattern, $actual];
        }
        $parts = preg_split('#(%)#', $pattern, -1, PREG_SPLIT_DELIM_CAPTURE);
        for ($i = count($parts); $i >= 0; $i--) {
            $patternX = implode(array_slice($parts, 0, $i));
            $patternY = "{$patternX}%A?%";
            if (self::isMatching($patternY, $actual)) {
                $patternZ = implode(array_slice($parts, $i));
                break;
            }
        }
        foreach (['%A%', '%A?%'] as $greedyPattern) {
            if (substr($patternX, -strlen($greedyPattern)) === $greedyPattern) {
                $patternX = substr($patternX, 0, -strlen($greedyPattern));
                $patternY = "{$patternX}%A?%";
                $patternZ = $greedyPattern . $patternZ;
                break;
            }
        }
        $low = 0;
        $high = strlen($actual);
        while ($low <= $high) {
            $mid = $low + $high >> 1;
            if (self::isMatching($patternY, substr($actual, 0, $mid))) {
                $high = $mid - 1;
            } else {
                $low = $mid + 1;
            }
        }
        $low = $high + 2;
        $high = strlen($actual);
        while ($low <= $high) {
            $mid = $low + $high >> 1;
            if (!self::isMatching($patternX, substr($actual, 0, $mid), TRUE)) {
                $high = $mid - 1;
            } else {
                $low = $mid + 1;
            }
        }
        $actualX = substr($actual, 0, $high);
        $actualZ = substr($actual, $high);
        return [$actualX . rtrim(preg_replace('#[\\t ]*\\r?\\n#', "\n", $patternZ)), $actualX . rtrim(preg_replace('#[\\t ]*\\r?\\n#', "\n", $actualZ))];
    }