README.md

@shapeshiftoss/logger

ShapeShift DAO's simple logging library.

Installation

yarn add @shapeshiftoss/logger
# or
npm i @shapeshiftoss/logger

Initialization

import { Logger } from '@shapeshiftoss/logger'

const logger = new Logger({
  // name of the app or service
  namespace: ['Parent'],
  // alias: name: 'Parent'
  // severity threshold (default='info')
  level: 'debug',
  // extra fields to include on each message
  defaultFields: {
      fn: 'defaultFn'
  }
})

Custom logging output function

By default, the Logger will log a JSON string to the console.

You can customize this by providing a logFn option to the Logger constructor.

import { Logger } from '@shapeshiftoss/logger'
import type { LogLevel, LogData } from '@shapeshiftoss/logger'

const logger = new Logger({
  name: 'MyAppLogger',
  logFn: (level: LogLevel, data: LogData) => {
    myCentralLogger.send(JSON.stringify(data))
  }
})

Logging

Functions

• trace
• debug
• info
• warn
• error

Examples

// (string)
logger.info('my message')
// {"fn":"defaultFn","message":"my message",
//   "timestamp":"2021-10-25T17:48:33.255Z","namespace":"Parent","status":"info"}

// (object)
logger.debug({ txid: '123aef' })
// {"fn":"defaultFn","txid":"123aef",
//   "timestamp":"2021-10-25T17:49:21.105Z","namespace":"Parent","status":"debug"}

// (error)
logger.error(new Error('something went wrong'))
// {"fn":"defaultFn","error":{"message":"something went wrong","stack":"...snip...","kind":"Error"},
//  "timestamp":"2021-10-25T17:49:31.626Z","namespace":"Parent","status":"error"}

// (error, object, string)
logger.error(
    new Error('something went wrong'),
    { data: { orderId: '123-aef-33' }},
    'error occured while fetching order'
)
/*
{"fn":"defaultFn",
  "error":{"message":"something went wrong","stack":"...snip...","kind":"Error"},
  "data":{"orderId":"123-aef-33"},
  "message":"error occured while fetching order",
  "timestamp":"2021-10-25T17:50:53.101Z",
  "namespace":"Parent",
  "status":"error"
}
 */

Child loggers

const child = logger.child({ foo: 'bar' })
child.info({ biz: 'baz' }, 'hello!') 
// {"fn":"defaultFn","foo":"bar","biz":"baz","message":"hello!",
//   "timestamp":"2021-10-25T17:52:29.111Z","namespace":"Parent","status":"info"}

Namespacing

The namespace configuration property can be used to keep track of the depth/call stack.

When including namespace in a child, it APPENDS the values to the existing namespace making it easy to see in the output the chain that leads to the output.

const child2 = child.child({ namespace: ['MyModule', 'myFunction']})
child.info({ biz: 'baz' }, 'hello!') 
// {"fn":"defaultFn","biz":"baz","message":"hello!",
//   "timestamp":"2021-10-25T17:53:55.909Z","namespace":"Parent:MyModule:myFunction","status":"info"}

Reserved Properties

The following property names are reserved. If you want to log out an object that contains these property names, you'll need to nest it inside another object.

  'namespace'
  'timestamp'
  'status'