Rslog

A tiny, intuitive, type-friendly logger for Node.js.

• Tiny. 2kB gzipped.
• Clean. Zero dependencies.
• Intuitive. Clear log prefix.
• Type-friendly. Written in TypeScript.

Preview

Install

# with npm
npm add rslog

# with yarn
yarn add rslog

# with pnpm
pnpm add rslog

# with bun
bun add rslog

Rslog requires Node.js ^20.19.0 || >=22.12.0. If you are on Node 18, upgrade Node before using the package.

Usage

import { logger } from 'rslog';

• Log:

// A gradient welcome log
logger.greet(`\n➜ Rslog v1.0.0\n`);

// Info
logger.info('This is a info message');

// Start
logger.start('This is a start message');

// Warn
logger.warn('This is a warn message');

// Ready
logger.ready('This is a ready message');

// Success
logger.success('This is a success message');

// Error
logger.error('This is a error message');
logger.error(new Error('This is a error message with stack'));

// Debug
logger.debug('This is a debug message');

// Same as console.log
logger.log('This is a log message');

Log Level

You can create a new logger instance through createLogger and specify the log level:

import { createLogger } from 'rslog';

const logger = createLogger({ level: 'warn' });

// Will print
logger.error('This is a error message');
logger.warn('This is a warn message');

// Will not print
logger.info('This is a info message');
logger.log('This is a log message');

You can also directly modify the level attribute of the logger instance:

logger.level = 'verbose';

The log levels of each method are as follows:

| Level | Method | | ---------- | --------------------------------------------------- | | silent | No log will be output | | error | only error logs | | warn | warn | | info (log) | info, start, ready, success, log, greet | | verbose | debug |

Override

You can use logger.override to override some or all methods of the default logger.

import { logger } from 'rslog';

logger.override({
  log: message => {
    console.log(`[LOG] ${message}`);
  },
  info: message => {
    console.log(`[INFO] ${message}`);
  },
  warn: message => {
    console.log(`[WARN] ${message}`);
  },
  error: message => {
    console.log(`[ERROR] ${message}`);
  },
});

Options

You can read the original options passed to createLogger from logger.options:

import { createLogger } from 'rslog';

const logger = createLogger({
  prefix: '[web]',
  level: 'warn',
});

console.log(logger.options);
// { prefix: '[web]', level: 'warn' }

Custom Console

You can also provide a custom console implementation when creating a logger:

import { Console } from 'node:console';
import { createWriteStream } from 'node:fs';
import { createLogger } from 'rslog';

const customConsole = new Console({
  stdout: createWriteStream('./stdout.log'),
  stderr: createWriteStream('./stderr.log'),
});

const logger = createLogger({
  console: customConsole,
});

Prefix

You can prepend a fixed prefix to every log message:

import { createLogger } from 'rslog';

const logger = createLogger({
  prefix: '[web]',
});

logger.info('server started');
// info    [web] server started

Color

You can import color directly from rslog to style your own output:

It is a small wrapper around Node.js styleText, with a simpler API for common styling.

import { color, logger } from 'rslog';

logger.success(color.green('done'));
logger.info(color.bold(color.blue('build complete')));
logger.error(color.red('something went wrong'));

Environment

Rslog supports Node.js ^20.19.0 || >=22.12.0.

License

Rslog is MIT licensed.