Parallel Logger

A creative two-column side-by-side logging system for Node.js that displays logs in separate columns simultaneously.

Features

• Side-by-side logging: Display multiple log streams in parallel columns
• ANSI color support: Color-coded loggers for better visual distinction
• TypeScript support: Full TypeScript definitions included
• Flexible positioning: Automatic column calculation or custom positioning
• Real-time output: Concurrent logging with proper cursor positioning

Installation

npm install parallel-logger

Usage

Basic Example

import { ParallelLogger, colors, clearScreen, getColumnPosition } from 'parallel-logger';

// Clear the screen
clearScreen();

// Create loggers for different columns
const systemLogger = new ParallelLogger('SYSTEM', getColumnPosition('left'), colors.RED);
const appLogger = new ParallelLogger('APP', getColumnPosition('right'), colors.GREEN);

// Start logging
systemLogger.log('System starting...');
appLogger.log('Application initialized');

// Continue logging...
setInterval(() => {
  systemLogger.log(`Heartbeat ${Math.random().toFixed(2)}`);
}, 1000);

setInterval(() => {
  appLogger.log(`Event ${Math.random().toFixed(2)}`);
}, 1500);

Advanced Usage

import { ParallelLogger, colors } from 'parallel-logger';

// Custom column positions
const logger1 = new ParallelLogger('Logger1', 1, colors.BLUE);
const logger2 = new ParallelLogger('Logger2', 40, colors.YELLOW);
const logger3 = new ParallelLogger('Logger3', 80, colors.CYAN);

// Log with different intervals
setInterval(() => logger1.log('Fast log'), 500);
setInterval(() => logger2.log('Medium log'), 1000);
setInterval(() => logger3.log('Slow log'), 2000);

CommonJS (require) Usage

If you're in a CommonJS environment (e.g., older Node setups without type: module):

const { ParallelLogger, colors, clearScreen, getColumnPosition } = require('parallel-logger');

clearScreen();
const left = new ParallelLogger('LEFT', getColumnPosition('left'), colors.BLUE);
const right = new ParallelLogger('RIGHT', getColumnPosition('right'), colors.GREEN);
left.log('Hello from CJS');
right.log('Hi from CJS');

API Reference

ParallelLogger

Constructor

new ParallelLogger(name: string, column: number, color?: string)

• name: The logger name that appears in brackets
• column: The column position (1-based)
• color: Optional ANSI color code

Methods

• log(message: string): Log a message to the column
• reset(): Reset the row position to 1

Utility Functions

• clearScreen(): Clear the terminal screen
• getColumnPosition(position: 'left' | 'right' | number): Get column position
  • 'left': Column 1
  • 'right': Middle of terminal width
  • number: Custom column position

Colors

Available color constants:

• colors.RED
• colors.GREEN
• colors.BLUE
• colors.YELLOW
• colors.CYAN
• colors.MAGENTA
• colors.WHITE
• colors.RESET

Demo

Run the included demo:

npm run demo

Or with Bun:

bun run demo

Requirements

• Node.js >= 16.0.0
• Terminal that supports ANSI escape codes

License

MIT

Changelog

See CHANGELOG.md for release history.

Contributing

Contributions welcome! Please feel free to submit issues and pull requests.