EZ Typescript Logger

A simple to use, yet professional looking Logger for Typescript.

Supports json formatting for scraping the logs with Promtail for Loki/Grafana Stacks.

Install

npm i -S ez-ts-logger

Usage

import { Logger} from 'ez-ts-logger'

Logger.debug('A Debugging message')
Logger.info({
  Hello: 'World!',
  foo: {
    bar: true,
  },
})
Logger.warn('A Warning message')

Logger.error('An Error message')
Logger.error(new Error())

try {
  Logger.errorAndThrow(new CustomError('Some Message'))
} catch (e) {
  Logger.info('Caught')
}

Configuration

EZ Typescript Logger automatically gets its configuration from env vars (or default if undefined)

# 'trace', 'debug', 'info', 'warning', 'error' or 'critical'
LOG_LEVEL=info

# 'text', 'json' (json formatting for Loki/Promtail/Grafana and such)
LOG_OUTPUT=text

# If 'true', ignores log level when printing 'debug' message (always prints it)
DEBUGGING=false

# If 'true', will suppress all logs (used when running unit test)
TESTING=false

Full Showcase

const object = {
  created: new Date(),
  data: 123,
  more: {
    hello: 'world',
  },
}
const objectWithMessage = {
  message: 'My Message',
  created: new Date(),
  data: 123,
  more: {
    hello: 'world!',
  },
}

const error = new CustomError('Nothing actually happened')

//Force reload env configs.
//this is useful when you are populating env at runtime, for example with 'dotenv'
Logger.reloadEnvConfigs()

//Just some spacing for readibility
console.log()
console.log()

Logger.info('Before config update')
Logger.info(object)
Logger.info(objectWithMessage)

Logger.changeConfigs({ LOG_OUTPUT: 'json', LOG_LEVEL: LoggerLevels.trace })
console.log()
console.log()

Logger.info('json formatting')
Logger.info(objectWithMessage)

console.log()
console.log()

Logger.changeConfigs({ LOG_OUTPUT: 'text' })

Logger.trace('After config update')
console.log()

Logger.debug('A Debugging message')
console.log()

Logger.info('An Info message')
console.log()

Logger.warn('A Warning message')
Logger.warn(objectWithMessage)
Logger.warn(error)
console.log()

Logger.error('An Error message')
Logger.error(objectWithMessage)
Logger.error(error)
console.log()

Logger.critical('A Critical message')
Logger.critical(objectWithMessage)
Logger.critical(error)
console.log()

try {
  Logger.errorAndThrow(error)
} catch (e) {
  Logger.info(`Appplication failed successfully`)
} finally {
  console.log()
}

try {
  Logger.criticalAndThrow(error)
} catch (e) {
  Logger.info(`Appplication failed successfully`)
} finally {
  console.log()
}