@yukiakai/logger

A lightweight static logger for Node.js using native console.log but with log levels and debug-style control. Zero dependencies.

Human-friendly output.
Keep Node's beautiful console formatting, but control level like pino or debug.

Features

• Uses Node.js native console, keeps util.inspect formatting (colors, depth, etc.)
• Support debug, info, warn, error, fatal, silent
• Static & global, no instance needed.
• Control log level via process.env.LOG_LEVEL or code.
• Filter logs by caller file path via Logger.path.
• No dependencies. Zero overhead.

Install

npm i @yukiakai/logger

Usage

ESM (TS)

import { Logger } from '@yukiakai/logger';

// Set level once (global, static)
Logger.level = process.env.LOG_LEVEL as any || 'info';

// Custom filter log path
Logger.path = './src/';

Logger.info('Server started', { port: 3000 });
Logger.debug('Debug data', { foo: 123, bar: 456 });
Logger.warn('Warning', 'some detail');
Logger.error('Something failed', new Error('Oops'));

CJS

const { Logger } = require('@yukiakai/logger');

// Set level once (global, static)
Logger.level = process.env.LOG_LEVEL || 'info';

// Custom filter log path
Logger.path = './src/';

Logger.info('Server started', { port: 3000 });
Logger.debug('Debug data', { foo: 123, bar: 456 });
Logger.warn('Warning', 'some detail');
Logger.error('Something failed', new Error('Oops'));

Output example:

[INFO] Server started { port: 3000 }

[DEBUG] Debug data {
  foo: 123,
  bar: 456
}

[WARN] Warning some detail

[ERROR] Something failed Error: Oops
    at ...

Why?

• You don’t want to delete console.log everywhere when done debugging.
• You love Node’s console.log(a, b, c) style (no JSON lines, no forced format).
• You want debug-style control, but for structured console output.
• No external packages. No bloat.

Log Levels

| Level | Logs | |----------|----------------| | fatal | Fatal only | | error | Error + Fatal | | warn | Warn + Error | | info | Info + Warn + Error | | debug | All logs | | silent| Nothing |

Set via:

LOG_LEVEL=debug node app.js

Or in code:

Logger.level = 'warn';

Log Path

You can configure the logger to only log messages when called from specific files by setting the Logger.path option.

Set via code

Logger.path = './src/';

Default behavior

If Logger.path is not set, the logger will log from all files under the current working directory (process.cwd()), excluding any files inside node_modules/.

API

| Method | Description | |---------|-------------| | Logger.debug(...args) | Debug logs | | Logger.info(...args) | Info logs | | Logger.warn(...args) | Warn logs | | Logger.error(...args) | Error logs | | Logger.fatal(...args) | Fatal logs |

All methods accept console.log style arguments:
log(a, b, c, {d: 1})

Changelog

See full release notes in CHANGELOG.md

License

MIT © Yuki