example-app.js

const Logger = require('@simplybusiness/twiglet')

const PORT = 8080

const log = Logger('petshop')

// Start our petshop
log.info({
  event: {
    action: 'startup'
  },
  message: `Ready to go, listening on port ${PORT}`,
  server: {
    port: PORT
  }
})

// We get a request
const requestLog = log.with({ event: { action: 'HTTP request' }, trace: { id: '126bb6fa-28a2-470f-b013-eefbf9182b2d' }})

// Oh noes!
dbErr = true // this time!
if (dbErr) {
  requestLog.error({ message: 'DB connection failed.' })
}

// Example of an exception being logged together with a stack trace
// and a custom message e.g. during login
try {
  throw new Error("Oh noes!")
} catch(err) {
  requestLog.error({ message: 'Failed during customer login' }, err)
}

// We return an error to the requester
requestLog.info({ message: 'Internal Server Error', http: { request: { method: 'get'}, response: { status_code: 500 }}})

// Logging with a non-empty message is an anti-pattern and is therefore forbidden
// Both of the following lines would throw an error
// request_log.error()
// log.debug()