function getDirFromPath(req) {
    var path = req.header('path')

    if (path == null) {
        res.status(400).send('Path required')
    }

    path = 'files/' + path
    try {
        var dir = fs.opendirSync(path)
        return dir;
    } catch {
        if (fs.accessSync(path) != undefined) {
            console.log('Non-existing dir tried to be accessed.')
            res.status(400).send('Invalid path')
        }
        res.status(500).send('Failed to open directory')
        return -1;
    }
}

I can then check for -1 in the caller of this function. This seems inelegant though. Should I be doing some kind of exception throwing out of this function?