Node.js File Uploader App

A simple TCP-based file uploader application built with Node.js. This project demonstrates client-server communication for file transfers with progress tracking.

Overview

This application consists of two main components:

• Server: Listens for incoming connections and receives files
• Client: Connects to the server and uploads files with progress indication

Features

• 🚀 Fast TCP-based file transfer
• 📊 Real-time upload progress tracking
• 💾 Automatic file storage in dedicated directory
• 🔄 Backpressure handling for optimal performance
• 📝 Clean console output with progress updates

Project Structure

uploader-app/
├── server.js          # TCP server that receives files
├── client.js          # TCP client that uploads files
├── storage/           # Directory where uploaded files are saved
├── testing.txt        # Sample file for testing uploads
└── README.md          # This file

Installation

1. Clone or download this project

git clone https://github.com/vasylpryimakdev/node-js-uploader-app.git

2. Navigate to the project directory

cd node-js-uploader-app

3. No additional dependencies required - uses only Node.js built-in modules

Usage

Starting the Server

node server.js

The server will start listening on ::1:5050 and display:

Uploader server opened on { address: '::1', family: 'IPv6', port: 5050 }

Uploading Files

node client.js <file-path>

Example:

node client.js testing.txt

The client will:

• Connect to the server
• Display upload progress (0% to 100%)
• Show success message when complete

Testing with Sample File

# Start server in one terminal
node server.js

# Upload the test file in another terminal
node client.js testing.txt

How It Works

Server (server.js)

• Creates a TCP server on port 5050
• Handles multiple client connections
• Parses file headers to extract filenames
• Implements backpressure control with socket.pause()/resume()
• Saves files to the storage/ directory
• Properly closes file handles when connections end

Client (client.js)

• Connects to the server using TCP
• Sends file metadata in the format: fileName: <filename>-------
• Reads files in chunks and streams them to the server
• Displays real-time upload progress
• Handles backpressure with stream pausing/resuming
• Provides visual feedback with cursor control

Technical Details

• Protocol: Custom TCP protocol with simple header format
• Backpressure: Implemented using Node.js stream drain events
• Progress Tracking: Calculates percentage based on bytes transferred
• File Handling: Uses fs/promises for modern async file operations
• UI: Console-based progress display with cursor manipulation

Requirements

• Node.js (version with fs/promises support)
• No external dependencies

Notes

• The server stores all uploaded files in the storage/ directory
• The storage/ directory is created automatically if it doesn't exist
• Multiple concurrent uploads are supported
• The application handles large files efficiently through streaming
• IPv6 localhost (::1) is used by default for the connection

Example Output

Server:

New connection!
Connection ended!

Client:

Uploading... 25%
Uploading... 50%
Uploading... 75%
Uploading... 100%
The file was successfully uploaded!