🧠 Custom HTTP Server in TypeScript

This is a custom-built HTTP server built using Node.js and TypeScript to understand how HTTP works under the hood — without using any external libraries like Express.js.

🚀 Features

• ✅ Manually parses HTTP requests using Node's net module
• 🔁 Handles persistent and non-persistent connections (Connection: keep-alive/close)
• 🌍 Supports basic routing:
  • / → Returns Hello World!
  • /echo/:text → Echoes text back
  • /user-agent → Returns User-Agent header
  • /files/:filename (GET) → Serves files from a directory
  • /files/:filename (POST) → Saves uploaded file
• 📦 Supports gzip compression if Accept-Encoding: gzip is provided
• 🧠 Manually handles headers, request body, and byte streams

🛠️ How It Works

1. Create TCP Server

Using net.createServer(), a TCP server is started on localhost:4221. All data is received as raw byte streams.

2. Parse HTTP Request

The server splits requests on \r\n\r\n, separates the request line and headers, and stores them in a JS object.

3. Handle Routes

• / – Returns "Hello World!"
• /echo/:message – Echoes back the message; gzips it if Accept-Encoding: gzip is sent.
• /user-agent – Returns the value of the User-Agent header.
• /files/:filename:
  • GET – Reads the file from the directory passed with --directory flag.
  • POST – Writes the incoming body to that file path.

4. Handle Headers

• Content-Length is calculated manually.
• Content-Encoding is set when gzipping.
• Connection is honored to keep-alive or close the socket.

🧪 Example Usage

Start the server:

ts-node index.ts --directory ./data