public function addIndexFile($file, $type = 'cli')
    {
        $type = strtolower($type);

        if (!in_array($type, ['cli', 'web'])) {
            throw new \InvalidArgumentException(sprintf('Index file type "%s" is invalid, must be one of: cli, web', $type));
        }

        $this->index[$type] = [$file, realpath($this->path . DIRECTORY_SEPARATOR . $file)];
    }