mongodb开启auth，mongoose需要怎么连接？

现在目前的情况是控制台和用工具连接都没有问题，但是mongoose查询数据时就会报未授权的错误。

• 代码如下：

const connect =  ()=> {mongoose.connect('mongodb://username:password@127.0.0.1:27017/database');};
connect();
mongoose.connection.on('error', console.error.bind(console, 'connection error:'));
mongoose.connection.on('disconnected', connect);

• 然后试了这样子 还是不行

var options = {
    db: { native_parser: true },
    server: { poolSize: 5 },
    replset: { rs_name: 'userAdmin' },
    user: xxx
    pass: xxx
}
const connect =  ()=> {mongoose.connect('mongodb://xxx:xxx@127.0.0.1:27017/xxx',options)};
connect();
mongoose.connection.on('error', console.error.bind(console, 'connection error:'));
mongoose.connection.on('disconnected', connect);

var options = {
    db: { native_parser: true },
    server: { poolSize: 5 },
    replset: { rs_name: 'userAdmin' },
    user: xxx
    pass: xxx
}
const connect =  ()=> {mongoose.connect('mongodb://127.0.0.1:27017/xxx',options)};
connect();
mongoose.connection.on('error', console.error.bind(console, 'connection error:'));
mongoose.connection.on('disconnected', connect);

都不行，这个要怎么破？