info.message is concatenated with meta.message as is

[Damaged-Organic]

Please tell us about your environment:

• winston version?
  • winston@2
  • winston@3
• node -v outputs: v8.9.4
• Operating System? Linux
• Language? ES6/7

What is the problem?

If meta argument of a log method (destructured from splat rest parameters) is an Error-like object (e.g. having a message property), the original msg argument is concatenated with meta.message without any spaces, making the output unreadable.

Working example:

const { format, transports, createLogger } = require('winston')

const consoleTransport = new transports.Console({
  // General settings
  level: 'silly',
  format: format.combine(
    format.simple()
  )
})

const logger = createLogger({
  level: 'silly',
  transports: [consoleTransport]
})

logger.error('Description of other error', new Error('Other error'))

Example output:

error: Description of other errorOther error {"stack":"Error: Other error\n    at Object.<anonymous> (.../src/test.js:16:44)\n    at Module._compile (module.js:643:30)\n    at Object.Module._extensions..js (module.js:654:10)\n    at Module.load (module.js:556:32)\n    at tryModuleLoad (module.js:499:12)\n    at Function.Module._load (module.js:491:3)\n    at Function.Module.runMain (module.js:684:10)\n    at startup (bootstrap_node.js:187:16)\n    at bootstrap_node.js:608:3"}

What do you expect to happen instead?

The logged message is separated from the meta Error object message:

error: Description of other error Other error {"stack":"Error: Other error\n    at Object.<anonymous> (.../src/test.js:16:44)\n    at Module._compile (module.js:643:30)\n    at Object.Module._extensions..js (module.js:654:10)\n    at Module.load (module.js:556:32)\n    at tryModuleLoad (module.js:499:12)\n    at Function.Module._load (module.js:491:3)\n    at Function.Module.runMain (module.js:684:10)\n    at startup (bootstrap_node.js:187:16)\n    at bootstrap_node.js:608:3"}

Other information

The problem is really within the log method:

if (meta.message) info.message += `${meta.message}`;

Simply concatenating like that will definitely produce strange results. Having something like that will solve the problem:

if (meta.message) info.message = `${info.message} ${meta.message}`;

The best thing would be to not concatenate messages at all, having separate stack and meta object itself on the info.

[jfirebaugh]

Previously reported in #1634.

[DABH]

Closing as duplicate -- fixing though...