loglevel Transport

loglevel is a minimal lightweight logging library for JavaScript. It provides a simple logging API that works in both Node.js and browser environments.

Transport Source

Installation

npm

npm i @loglayer/transport-loglevel loglevel

pnpm

pnpm add @loglayer/transport-loglevel loglevel

yarn

yarn add @loglayer/transport-loglevel loglevel

Setup

import { LogLayer } from 'loglayer';
import { LogLevelTransport } from '@loglayer/transport-loglevel';
import log from 'loglevel';

const logger = log.getLogger('myapp');
logger.setLevel('trace'); // Enable all log levels

const loglayer = new LogLayer({
  transport: new LogLevelTransport({
    logger,
    // Optional: control where object data appears in log messages
    appendObjectData: false // default: false - object data appears first
  })
});

Configuration Options

appendObjectData

Controls where object data (metadata, context, errors) appears in the log messages:

• false (default): Object data appears as the first parameter
• true: Object data appears as the last parameter

Example with appendObjectData: false (default):

loglayer.withMetadata({ user: 'john' }).info('User logged in');
// logger.info({ user: 'john' }, 'User logged in')

Example with appendObjectData: true:

loglayer.withMetadata({ user: 'john' }).info('User logged in');
// logger.info('User logged in', { user: 'john' })

Log Level Mapping

LogLayer	loglevel
trace	trace
debug	debug
info	info
warn	warn
error	error
fatal	error