Solved-Printing Error Object in Winston

utils-deep-clone

Deep clones any json datatype

Installation

yarn add utils-deep-clone

npm install utils-deep-clone

Motivation

utils-deep-clone is designed specifically for winstonJS but it can be used wheresoever required. WinstonJS have an open bug that if you pass Error data type nested inside Object or nested inside any other data type then because Error being enumerable it won't get printed in logs. So to handle this here's a workaround. Just call toJSON function before calling winston.log and pass the response object in it. An example for this is given at the bottom.

Normal DeepCloning - THE NEED

const someError = new Error('Something wrong happened')
  const someError2 = new Error('Something wrong happened again')
  const someError3 = new Error('Something wrong happened again again')
  
  someError3.someData = 'Some data'
  someError3.isActive = true
  
  var obj = {
    someError,
    nestedValue: {
      someError2
    },
    arrayValue: ['value1' ,'value2', someError3]
  }
  console.log(JSON.parse(JSON.stringify(obj)))

Response:

{ someError: {},
  nestedValue: { someError2: {} },
  arrayValue: [ 'value1', 'value2', { someData: 'Some data', isActive: true } ] }

Error is not getting printed because of it's enumerable property.

Usage - THE SOLUTION

Now doing the same thing with utils-deep-clone

const { toJSON } = require('utils-deep-clone')

  const someError = new Error('Something wrong happened')
  const someError2 = new Error('Something wrong happened again')
  const someError3 = new Error('Something wrong happened again again')
  
  someError3.someData = 'Some data'
  someError3.isActive = true
  
  var obj = {
    someError,
    nestedValue: {
      someError2
    },
    arrayValue: ['value1' ,'value2', someError3]
  }
  toJSON(obj).then((newObj)=>{
    console.log(newObj)
  }).catch(error => {
    // handle error
  })

Response:

{ someError: 
   { message: 'Something wrong happened',
     stack: 'Error: Something wrong happened\n    at Object.<anonymous> (/Users/atishay/Documents/utils-error-deep-log/Untitled-1.js:3:19)\n    at Module._compile (module.js:652:30)\n    at Object.Module._extensions..js (module.js:663:10)\n    at Module.load (module.js:565:32)\n    at tryModuleLoad (module.js:505:12)\n    at Function.Module._load (module.js:497:3)\n    at Function.Module.runMain (module.js:693:10)\n    at startup (bootstrap_node.js:188:16)\n    at bootstrap_node.js:609:3' },
  arrayValue: 
   [ 'value1',
     'value2',
     { message: 'Something wrong happened again again',
       stack: 'Error: Something wrong happened again again\n    at Object.<anonymous> (/Users/atishay/Documents/utils-error-deep-log/Untitled-1.js:5:20)\n    at Module._compile (module.js:652:30)\n    at Object.Module._extensions..js (module.js:663:10)\n    at Module.load (module.js:565:32)\n    at tryModuleLoad (module.js:505:12)\n    at Function.Module._load (module.js:497:3)\n    at Function.Module.runMain (module.js:693:10)\n    at startup (bootstrap_node.js:188:16)\n    at bootstrap_node.js:609:3',
       someData: 'Some data',
       isActive: true } ],
  nestedValue: 
   { someError2: 
      { message: 'Something wrong happened again',
        stack: 'Error: Something wrong happened again\n    at Object.<anonymous> (/Users/atishay/Documents/utils-error-deep-log/Untitled-1.js:4:20)\n    at Module._compile (module.js:652:30)\n    at Object.Module._extensions..js (module.js:663:10)\n    at Module.load (module.js:565:32)\n    at tryModuleLoad (module.js:505:12)\n    at Function.Module._load (module.js:497:3)\n    at Function.Module.runMain (module.js:693:10)\n    at startup (bootstrap_node.js:188:16)\n    at bootstrap_node.js:609:3' } } }

Debugging

const { toJSON, debug } = require('utils-deep-clone')
  
  // Simply Call this for getting debug logs
  debug()
  
  const someError = new Error('Something wrong happened')

  toJSON(someError, (err, newObj) => {
    if (err) {
      // handle error
    }
    // do something
  })

Winston Bug

Here's the example from winston 2.x but the same bug exists in winston 3.x also.

const winston = require('winston')
const winstonLogger = new (winston.Logger)({
  transports: [
    new (winston.transports.Console)()
  ]
})

const log = (message, payload) => {
  return winstonLogger.log('info', message, payload)
}

const testObj = {
  error: new Error('Nothing will happen')
}

log('Testing few bugs', testObj)

Response:

info: Testing few bugs

Now, we'll be also using utils-deep-clone

const winston = require('winston')
const { toJSON } = require('utils-deep-clone')

const winstonLogger = new (winston.Logger)({
  transports: [
    new (winston.transports.Console)()
  ]
})

const log = async (message, payload) => {
  try {
    payload = await toJSON(payload)
    return winstonLogger.log('info', message, payload)
  } catch(error) {
    console.error('some error occured while consoling')
  }
}

const testObj = {
  error: new Error('It should work')
}

log('Testing few bugs', testObj)

Response:

info: Testing few bugs message=It should work, stack=Error: It should work
    at Object.<anonymous> (/Users/atishay/Desktop/utils-error-deep-log/logger.js:20:10)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at tryModuleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
    at Function.Module.runMain (module.js:693:10)
    at startup (bootstrap_node.js:188:16)
    at bootstrap_node.js:609:3