Add timestamps to log messages

In Chrome you can use “Show timestamps” to see timestamps next to your log messages. Unfortunately, this does not work in Node.js. Therefore we should add an option to automatically print timestamps together with the log message.

Proposal

const logdown = require('logdown')
const logger = logdown('MyLogger', { markdown: false, timestamp: true })
logger.log('Hello, World!')

Proposed Output

[2017-03-13 12:15:03.137] MyLogger Hello, World!

[bennycode]

It’s great that logdown is extensible! I really like such architecture!

However, I think logging the time is a core functionality of a log library. There is a reason that Google implemented timestamps for console.log statements in Chrome.

As a compromise it would be great if we can supply a hook for the formatter, which makes it easier to modify texts before they get logged. Here is a great example from js-logger:

Logger.createDefaultHandler({
	formatter: function(messages, context) {
		// prefix each log message with a timestamp.
		messages.unshift(new Date().toUTCString())
	}
});

Currently I am extending logdown with timestamps like this:

import * as moment from 'moment'

class LogUtil {
  static padding: number = 25

  static addTimestamp(transObj: any) {
    if (~transObj.msg.indexOf('MyNamespace::')) {
      transObj.args.unshift(`[${moment().format('HH:mm:ss')}]`)
    }
  }

  static createName(className: string): string {
    className = `moon:${className}`
    const name = className.split('')
    while (name.length < this.padding) name.push(' ')
    return name.join('')
  }
}

export default LogUtil

const logdown = require('logdown')
logdown.transports = [LogUtil.addTimestamp]

const logger = logdown(LogUtil.createName('MyLogger'), {
  logger: console,
  prefixColor: '#3a38e8',
})

[caiogondim]

Wouldn’t you agree that having timestamps is more essential than having markdown support for log messages? If that’s the case, then we should also outsource the markdown rendering into a plugin.

Not actually. The initial idea of the lib was to wrap console with a markdown parser and debug compatibility. But again, I’m open to adding a timestamp capability.

Log statements are small one-liners that programmers write in their source code. Imagine the frustation of people, when they now have to import 3 packages (tubo, logdown & logdown-with-timestamp) in order to log a single line of text. That’s far from being handy.

You don’t have to import tubo. That’s is just a wrapper for better pipeline pattern.

const logdown = withTimestamp(logdown('foo'))

It’s okay when developers at Babel or Webpack build an ecosystem around their software, because they have a whole framework to offer. But establishing a community and an ecosystem for a logging utility sounds over ambitious to me.

To create a “ecosystem” is not the goal I first mentioned, but rather keeping the library as simple as possible. And extensible.

But again, timestamp is something that makes sense to have in the library. Go ahead if you fancy implementing it.