bun-pty

bun-pty

A cross-platform pseudo-terminal (PTY) implementation for Bun, powered by Rust's portable-pty library and Bun's FFI capabilities.

🚀 Features

• Cross-platform - Works on macOS, Linux, and Windows
• Simple API - Clean Promise-based API similar to node-pty
• Type-safe - Complete TypeScript definitions included
• Efficient - Rust backend with proper error handling and multithreading
• Zero dependencies - No external JavaScript dependencies required
• Modern - Built specifically for Bun using its FFI capabilities

📦 Installation

bun add bun-pty

⚙️ Requirements

• Bun 1.0.0 or higher
• Rust is only needed if you're building from source (the npm package includes pre-built binaries)

📋 Platform Support

Platform	Status	Notes
macOS	✅	Fully supported
Linux	✅	Fully supported
Windows	✅	Fully supported

🚦 Usage

Basic Example

import { spawn } from "bun-pty";

// Create a new terminal
const terminal = spawn("bash", [], {
  name: "xterm-256color",
  cols: 80,
  rows: 24
});

// Handle data from the terminal
terminal.onData((data) => {
  console.log("Received:", data);
});

// Handle terminal exit
terminal.onExit(({ exitCode, signal }) => {
  console.log(`Process exited with code ${exitCode} and signal ${signal}`);
});

// Write to the terminal
terminal.write("echo Hello from Bun PTY\n");

// Resize the terminal
terminal.resize(100, 40);

// Kill the process when done
setTimeout(() => {
  terminal.kill();
}, 5000);

TypeScript Usage

The library includes complete TypeScript definitions. Here's how to use it with full type safety:

import { spawn } from "bun-pty";
import type { IPty, IExitEvent, IPtyForkOptions } from "bun-pty";

// Create typed options
const options: IPtyForkOptions = {
  name: "xterm-256color",
  cols: 100,
  rows: 30,
  cwd: process.cwd()
};

// Create a terminal with proper typing
const terminal: IPty = spawn("bash", [], options);

// Typed event handlers
const dataHandler = terminal.onData((data: string) => {
  process.stdout.write(data);
});

const exitHandler = terminal.onExit((event: IExitEvent) => {
  console.log(`Process exited with code: ${event.exitCode}`);
});

// Clean up when done
dataHandler.dispose();
exitHandler.dispose();

Interactive Shell Example

import { spawn } from "bun-pty";
import { createInterface } from "node:readline";

// Create a PTY running bash
const pty = spawn("bash", [], {
  name: "xterm-256color",
  cwd: process.cwd()
});

// Forward PTY output to stdout
pty.onData((data) => {
  process.stdout.write(data);
});

// Send user input to the PTY
process.stdin.on("data", (data) => {
  pty.write(data.toString());
});

// Handle PTY exit
pty.onExit(() => {
  console.log("Terminal session ended");
  process.exit(0);
});

// Handle SIGINT (Ctrl+C)
process.on("SIGINT", () => {
  pty.kill();
});

📖 API Reference

spawn(file: string, args: string[], options: IPtyForkOptions): IPty

Creates and spawns a new pseudoterminal.

• file: The executable to launch
• args: Arguments to pass to the executable
• options: Configuration options
  • name: Terminal name (e.g., "xterm-256color")
  • cols: Number of columns (default: 80)
  • rows: Number of rows (default: 24)
  • cwd: Working directory (default: process.cwd())
  • env: Environment variables

Returns an IPty instance.

IPty Interface

interface IPty {
  // Properties
  readonly pid: number;        // Process ID
  readonly cols: number;       // Current columns
  readonly rows: number;       // Current rows
  readonly process: string;    // Process name
  
  // Events
  onData: (listener: (data: string) => void) => IDisposable;
  onExit: (listener: (event: IExitEvent) => void) => IDisposable;
  
  // Methods
  write(data: string): void;   // Write data to terminal
  resize(cols: number, rows: number): void;  // Resize terminal
  kill(signal?: string): void;  // Kill the process
}

Event Types

interface IExitEvent {
  exitCode: number;
  signal?: number | string;
}

interface IDisposable {
  dispose(): void;
}

🧪 Testing

bun-pty uses Bun's built-in test runner for fast, Jest-compatible testing.

# Run all tests
bun test

# Run unit tests only
bun run test:unit

# Run integration tests (requires Rust library)
bun run test:integration

# View test coverage
bun run test:coverage

🔧 Building from Source

If you want to build the package from source:

# Clone the repository
git clone https://github.com/sursaone/bun-pty.git
cd bun-pty

# Install dependencies
bun install

# Build Rust library and TypeScript
bun run build

# Run tests
bun test

❓ Troubleshooting

Prebuilt Binaries

The npm package includes prebuilt binaries for macOS, Linux, and Windows. If you encounter issues with the prebuilt binaries, you can build from source:

# In your project directory
bun add bun-pty
cd node_modules/bun-pty
bun run build

Common Issues

• Error: Unable to load shared library: Make sure you have the necessary system libraries installed.
• Process spawn fails: Check if you have the required permissions and paths.

📚 Documentation

• CHANGELOG.md - Version history and changes

📄 License

This project is licensed under the MIT License.

🙏 Credits

• Built specifically for Bun
• Uses portable-pty from WezTerm for cross-platform PTY support
• Inspired by node-pty for the API design