我正在使用 Node 7.2.1 和新版本异步/等待特征。我还将 Native ES6 Promises 与 mongoose 一起使用,如下所示 -
const mongoose = require('mongoose');
mongoose.Promise = global.Promise;
我的代码流程是这样的 -
async function getFollowers(){
try {
const followers = await User.getFollowersFromMongo(req.params.userId);
res.send(followers);
} catch (err) {
winston.error('Printing Error = ', err);
res.status(400).send({success: false, error: err});
}
}
UserSchema.statics.getFollowersFromMongo = async(userId) => {
try {
let aggregateQuery = []; //some syntactical error in mongo query to produce exception
const followers = await User.aggregate(aggregateQuery);
return followers.map(follower => follower.followerData);
}
catch (err) {
return Promise.reject(err);
}
};
这段代码工作得非常好。当产生一些错误时就会出现问题。所以我特意修改了我的mongoose查询以便MongoDB会抛出一个错误。
现在,MongoDB 正如预期的那样抛出一个错误,该错误被我的代码完美捕获,并以 400 错误代码返回给客户端。
问题是,即使错误(故意的)已被我发现,Node.js仍然给我这个警告 -
error: Printing Error = MongoError: path option to $unwind stage should be prefixed with a '$': followerData
at Function.MongoError.create (/home/node_modules/mongodb-core/lib/error.js:31:11)
at /home/node_modules/mongodb-core/lib/connection/pool.js:483:72
at authenticateStragglers (/home/node_modules/mongodb-core/lib/connection/pool.js:429:16)
at Connection.messageHandler (/home/node_modules/mongodb-core/lib/connection/pool.js:463:5)
at Socket.<anonymous> (/home/node_modules/mongodb-core/lib/connection/connection.js:317:22)
at emitOne (events.js:96:13)
at Socket.emit (events.js:188:7)
at readableAddChunk (_stream_readable.js:176:18)
at Socket.Readable.push (_stream_readable.js:134:10)
at TCP.onread (net.js:551:20)
GET /user/385/followers 400 39.868 ms - 263
(node:10158) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): MongoError: path option to $unwind stage should be prefixed with a '$': followerData
(node:10158) DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
可以看出,我的请求已返回 400 状态,并且我的错误日志也已从初始方法的 catch 块中打印出来,但是Node.js仍然说错误消息未处理。
为什么在发现同样的错误后仍然这么说?
Update -感谢@dvlsg和@Bergi,该bug已在4.7.5版本中修复