Exception: winston.Logger is not a constructor

[BabyToy]

An exception is thrown when initializing express-winston, apparently the error is in:
express-winston/index.js

I think the latest update to Winston broke this build.

[bithavoc]

can you add the stack trace?

[lqshow]

winston UPGRADE-3.0.md

[bithavoc]

This should be part of the winston-3 branch https://github.com/bithavoc/express-winston/tree/winston-3 @makrandgupta is on it.

[BabyToy]

Attached is the stack trace:

TypeError: winston.Logger is not a constructor
    at new winstonLogger (common\logWinston.js:28:20)
    at Object.<anonymous> (common\gracefulExit.js:8:17)
    at Module._compile (internal/modules/cjs/loader.js:702:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:713:10)
    at Module.load (internal/modules/cjs/loader.js:612:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:551:12)
    at Function.Module._load (internal/modules/cjs/loader.js:543:3)
    at Module.require (internal/modules/cjs/loader.js:650:17)
    at require (internal/modules/cjs/helpers.js:20:18)```

[fega]

 options.winstonInstance = options.winstonInstance || (new winston.Logger ({ transports: options.transports }));
                                                          ^

TypeError: winston.Logger is not a constructor
    at Object.errorLogger (/mnt/c/Users/Acer/projects/coachtools/backend/node_modules/express-winston/index.js:120:59)
    at Object.<anonymous> (/mnt/c/Users/Acer/projects/coachtools/backend/src/server.js:99:28)
    at Module._compile (module.js:652:30)
    at loader (/mnt/c/Users/Acer/projects/coachtools/backend/node_modules/babel-register/lib/node.js:144:5)
    at Object.require.extensions.(anonymous function) [as .js] (/mnt/c/Users/Acer/projects/coachtools/backend/node_modules/babel-register/lib/node.js:154:7)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)

[surfaceowl]

After upgrading Winston to 3.0.0, and updating our code to use: const logger = new (winston.createLogger)({ we are getting a similar "not a constructor error"

How should we troubleshoot and fix this?

const logger = new (winston.createLogger)({ 
               ^ 
TypeError: winston.createLogger is not a constructor 
    at Object.<anonymous> (/app/server/src/helpers/logger.js:6:16) 
    at Module._compile (internal/modules/cjs/loader.js:702:30) 
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:713:10) 
    at Module.load (internal/modules/cjs/loader.js:612:32) 
    at tryModuleLoad (internal/modules/cjs/loader.js:551:12) 
    at Function.Module._load (internal/modules/cjs/loader.js:543:3) 
    at Function.wrappedLoad [as _load] (/app/server/node_modules/newrelic/lib/shimmer.js:324:38) 
    at Module.require (internal/modules/cjs/loader.js:650:17) 
    at require (internal/modules/cjs/helpers.js:20:18) 
    at Object.<anonymous> (/app/server/src/helpers/error-helper.js:1:78) 
    at Module._compile (internal/modules/cjs/loader.js:702:30) 
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:713:10) 
    at Module.load (internal/modules/cjs/loader.js:612:32) 
    at tryModuleLoad (internal/modules/cjs/loader.js:551:12) 
    at Function.Module._load (internal/modules/cjs/loader.js:543:3) 
    at Function.wrappedLoad [as _load] (/app/server/node_modules/newrelic/lib/shimmer.js:324:38) 
    at Module.require (internal/modules/cjs/loader.js:650:17) 
    at require (internal/modules/cjs/helpers.js:20:18) 
    at Object.<anonymous> (/app/server/src/core/express.js:18:21) 
    at Module._compile (internal/modules/cjs/loader.js:702:30) 
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:713:10) 
    at Module.load (internal/modules/cjs/loader.js:612:32)

[Kogs]

@surfaceowl createLogger is a function. so just use const logger = winston.createLogger(...

[Vascal]

Solved this by:
npm uninstall winston
then:
npm install winston@2.4.3

[juan55860]

Great @Vascal thanks a lot for the info.

[surfaceowl]

@Kogs -- thanks for the fix, that was it. Am still playing around with the new formatting options.

[DanGDroid]

as @Kogs said:
if using "winston": "^3.0.0" do:

var logger = winston.createLogger({
  
 transports: transports
});

and if using older "winston": "^2.4.0" do:

var logger = new winston.Logger({
  
 transports: transports
});

[Kogs]

Yep, but you need to keep in mind that also the transports are configured in a different way with winston": "^3.0.0.

[hiro5id]

This isn't really solved by installing older version of winston. It is only a temporary workaround.
We still need a proper fix for this so that we can use the latest version of winston.

Solved this by:
npm uninstall winston
then:
npm install winston@2.4.3

[ghCarol]

@hiro5id I agree. The problem is not fixed thoroughly. I am using 'express-winston' in addition with 'winston' like this:

app.use(expressWinston.logger({
  transports: [
    new (winston.transports.Console)({
      json: true,
      colorize: true
    }),
    new winston.transports.File({
      filename: 'logs/success.log'
    })
  ]
}))

Here I'm using "express-winston": "^2.5.1"
If I use winston@3.0.0, this problem pops out. I can only replace it with the older version. However, I still want to keep up with the latest version of winston if possible.

[bithavoc]

@makrandgupta what's the ETA for winston-3 support?

[bithavoc]

summoning @makrandgupta

[makrandgupta]

My apologies for going dark. I have had no time to work in this. Everything that I did is already pushed into the v3 branch. I could assist another developer make the port happen but won't be able to take point on this one.

[bithavoc]

Oki doki @makrandgupta

Any other volunteer? I’m gonna add a message to the Readme asking for contributors.

[lcssanches]

Guys,

I was able to get it running with this:

app.use(expressWinston.errorLogger({
  winstonInstance: winston.createLogger({
    transports: [
      new winston.transports.Console({
        json: true,
        colorize: true
      })
    ]
  }),
  exceptionToMeta: function(err){
    return err;
  },
}));

[blendedmarket]

Getting an error when creating an instance of the logger?

Anyone who has used this site, make sure to replace all instances of
const logger = new (winston.logger)
replace with -
const logger = (winston.createLogger)({
drop the new and rename the funciton createLogger and you are good to go!

[rosston]

A PR was merged recently (#178) to clarify that the current version of express-winston only supports winston <3. I realize this "fix" is not ideal, but it does prevent users from seeing the error reported here and allows us to add winston@3 support when we're ready.

Between the above change, and the fact that we have an issue open for adding winston@3 support (#163), I think this issue is redundant, so I'm going to close it.