Meta is broken again in 5.0.0

[arcreigh]

The below code does not work when trying to set the metadata currently in version 5.0.0
Rolling back to 4.0.9 was my only option.

is there a new way to setting metadata?

in 3.0.0 you could simply set winston.error(err.message, err) and the second argument would automatically populate the meta field in mongo. now I need to set the parameters via an object in 4.0.9. So what is the new way for 5.0.0?

const winston = require('winston');
module.exports = function(err, req, res, next){
console.log(err);
winston.error({message:err.message, meta:err});
res.status(500).send('something went wrong...');
}

[soldatovsh]

try this:

new transports.MongoDB({
        ...config.mongoDB,
        format: format.printf((info) => { 
          const splat = info[Symbol.for("splat")]                 
          info.metadata = splat && splat[0] || null
        }),
      })

[leodinas-hao]

Have the same issue. I'm using "winston": "3.2.1" with "winston-mongodb": "5.0.1".
The meta data gets lost, but it's there in other transports.

In addition, I tried above, but it doesn't work for me.

Downgrade "winston-mongodb" to v4.0.9 and the issue resolved

[MastroLindus]

It seems to me that it's not broken, but it has a different API from normal winston.
Winston considers metadata any property in the options object that are not "level" and "message", while this library specifically looks for a metakey property that defaults to "metadata" and is configurable when creating the logger.
I think the behavior should be changed to follow the normal winston API as it is both confusing and not conforming to the other transports

[yurijmikhalevich]

@MastroLindus changing the API to agree with the default winston API makes sense. The change will be included in the next update.

[HugoPoi]

Workaround 1

  const winston = require('winston');
  require('winston-mongodb');
  const _ = require('lodash');

  const insertMetaForWinstonMongo = winston.format(logEntry => {
    logEntry.metadata = _.chain(logEntry).omit(logEntry, ['level', 'message']).omitBy((value, key) => _.isSymbol(key)).value();
   // For winston-mongodb < 5.x  I was using
   // logEntry.meta = _.chain(logEntry).omit(logEntry, ['level', 'message']).omitBy((value, key) => _.isSymbol(key)).value();
    return logEntry;
  });

  const logger = winston.createLogger({
        transports: [new winston.transports.MongoDB()],
        format: insertMetaForWinstonMongo(),
      });

EDIT Workaround 2

  const winston = require('winston');
  require('winston-mongodb');

  const insertMetaForWinstonMongo = winston.format(logEntry => {
    logEntry.metadata = logEntry.meta;
    return logEntry;
  });

  const logger = winston.createLogger({
        transports: [new winston.transports.MongoDB()],
        format: winston.format.combine(winston.format.splat(), insertMetaForWinstonMongo()),
      });

It's a breacking change in 5.x

[leviwheatcroft]

@HugoPoi 's formatter in un-lodash is something like:

const insertMetaForWinstonMongo = winston.format((logEntry) => {
  const metaEntries = Object.entries(logEntry).filter(([key]) => {
    return (key !== 'level' && key !== 'message' && typeof key !== 'symbol')
  })
  logEntry.metadata = Object.fromEntries(metaEntries)
  return logEntry
})

[Rinidh]

@yurijmikhalevich : the winston-mongodb API has not yet been changed to match the winston API to allow easily pass meta data, without extra format configurations

[Rinidh]

Currently, as with winston-mongodb v5.1.1 and winston v3.11.0, only @HugoPoi 's Workaround 1 works as best configurations to apply