`exisjs/logger`

The exisjs/logger module provides structured logging powered by Pino. It includes a single-line terminal formatter for development, structured NDJSON output for production environments, automatic credential redaction, request-scoped loggers, and distributed tracing integration.

Module Exports

import {  logger,  configureLogger,  setLogger,  createLogger,  createSilentLogger,  isLogger,  formatBytes,  formatLatency,  formatMethod,  formatStatus,  formatUrl,  formatIp,  extractValidationSummary,  extractErrorMessage,} from 'exisjs/logger'
import type { Logger, LoggerConfig } from 'exisjs/logger'

Global Logger Singleton (`logger`)

logger is a global proxy satisfying the Logger interface. It can be imported and executed anywhere across controllers, services, repositories, or background tasks.

import { logger } from 'exisjs/logger'
// Level logging methodslogger.info('Payment service initialized')logger.warn({ ip: req.ip, attempts: 3 }, 'Multiple failed login attempts')logger.error({ err, orderId: 'ord_123' }, 'Stripe webhook processing failed')logger.debug({ payload }, 'Parsed RPC frame')logger.trace('Entering database connection pool checkout')logger.fatal({ err }, 'Unrecoverable process state')
// Contextual child loggersconst workerLogger = logger.child({ workerId: 'worker-1', queue: 'emails' })workerLogger.info('Processing email batch')

`Logger` Interface

export interface LogFn {  (msg: string, ...args: unknown[]): void  (obj: Record<string, unknown>, msg?: string, ...args: unknown[]): void}
export interface Logger {  fatal: LogFn  error: LogFn  warn: LogFn  info: LogFn  debug: LogFn  trace: LogFn  silent: LogFn  child(bindings: Record<string, unknown>): Logger  level: string}

Configuration (`configureLogger`)

Configures global logger settings, default log levels, terminal pretty printing, and sensitive field redaction.

function configureLogger(  config: LoggerConfig & { replaceRedact?: boolean }): void

Options Reference (`LoggerConfig`)

Property	Type	Default	Description
`level`	`'fatal' \| 'error' \| 'warn' \| 'info' \| 'debug' \| 'trace' \| 'silent'`	`'info'`	Minimum severity level to emit.
`pretty`	`boolean`	`NODE_ENV !== 'production'`	Whether to use formatted single-line terminal output or raw NDJSON.
`redact`	`string[]`	See Redaction section	Array of object property paths to censor.
`replaceRedact`	`boolean`	`false`	When `true`, overrides the default redact list instead of merging with it.

Example

src/http/server.ts

import { configureLogger } from 'exisjs/logger'
configureLogger({  level: process.env.NODE_ENV === 'production' ? 'info' : 'debug',  pretty: process.env.NODE_ENV !== 'production',  redact: ['*.password', '*.token', '*.secret', 'req.headers.cookie'],})

Custom Logger Replacement (`setLogger`)

Replaces the underlying global logger instance with a custom Pino instance or third-party logger implementing the Logger interface.

function setLogger(custom: Logger): void

Example: Custom Transport with `pino-loki`

src/http/server.ts

import { setLogger } from 'exisjs/logger'import pino from 'pino'
const customPino = pino({  level: 'info',  transport: {    target: 'pino-loki',    options: { host: 'http://localhost:3100' },  },})
setLogger(customPino)

Sensitive Data Redaction

By default, the logger censors sensitive fields in logged objects, replacing values with "[Redacted]" before serialization:

const DEFAULT_REDACT = [  'req.headers.authorization',  'req.headers.cookie',  'req.body.password',  'req.body.token',  'req.body.secret',  '*.password',  '*.token',  '*.secret',  'password',  'token',  'secret',]

Request-Scoped Logging (`req.log`)

Every incoming ExisRequest provides a lazy child logger bound to req.log containing contextual request metadata:

requestId: Unique request identifier (req.requestId).
method: HTTP method (e.g. GET, POST).
url: Request path.

src/http/orders/route.ts

import { controller, route } from 'exisjs/router'
export default controller({  create: route.post('/', {    async handle({ req, body }) {      req.log.info({ orderId: body.id }, 'Creating order record')      return { success: true }    },  }),})

Distributed Tracing & OpenTelemetry

When @opentelemetry/api is present in the application runtime, log entries automatically include active distributed tracing identifiers:

{  "level": 30,  "time": 1774286390000,  "trace_id": "4bf92f3577b34da6a3ce929d0e0e4736",  "span_id": "00f067aa0ba902b7",  "msg": "Order created successfully"}

Formatting Utilities

The module exports helper utilities for formatting terminal outputs:

Function	Signature	Output Example
`formatBytes`	`(bytes?: number) => string`	`1420` -> `'1.4 KB'`
`formatLatency`	`(ms?: number) => string`	`14.5` -> `'\x1b[32m14.5ms\x1b[0m'`
`formatMethod`	`(method?: string) => string`	`'GET'` -> `'\x1b[1;36mGET \x1b[0m'`
`formatStatus`	`(status: number) => string`	`200` -> `'\x1b[1;32m200 OK\x1b[0m'`
`formatIp`	`(ip?: string) => string`	`'192.168.1.10'` -> formatted IP string
`createSilentLogger`	`() => Logger`	Returns a no-op logger instance
`isLogger`	`(obj: unknown) => obj is Logger`	Type guard checking `Logger` compliance

Continue to DI Reference Edit this page on GitHub

exisjs/logger

Module Exports

Global Logger Singleton (logger)

Logger Interface

Configuration (configureLogger)

Options Reference (LoggerConfig)