@dephub/spawn 🚀

A lightweight, fluent API for spawning child processes in Node.js. Enhanced wrapper around child_process.spawn with better defaults and convenience methods.

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Features ✨

• 🛠️ Fluent API - Chainable command building with SpawnBuilder
• 🔧 Multiple Modes - spawn, spawnSilent, spawnStream for different use cases
• 📡 Enhanced Options - Extended spawn options with encoding support
• 🔒 Type Safe - Full TypeScript support with strict typing
• 🚀 Lightweight - Minimal wrapper around native child_process
• 💻 Cross-Platform - Consistent behavior across Windows, macOS, Linux

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Installation 📦

npm install @dephub/spawn
# or
pnpm add @dephub/spawn
# or
yarn add @dephub/spawn

---

Quick Start 🚀

import { spawn, spawnStream, spawnSilent, SpawnBuilder } from '@dephub/spawn';

// Basic spawn with output capture
const result = await spawn('ls', ['-la']);
console.log(result.stdout);

// Stream output to parent process
await spawnStream('npm', ['install']);

// Silent execution with captured output
const silentResult = await spawnSilent('node', ['script.js']);

// Fluent builder API
const builderResult = await new SpawnBuilder()
  .command('ls')
  .arg('-la')
  .setOption('cwd', './src')
  .run();

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Usage Examples 🎯

Basic Command Execution

import { spawn } from '@dephub/spawn';

// Run simple command
const { code, stdout, stderr } = await spawn('echo', ['hello world']);

// Check exit code
if (code === 0) {
  console.log('Success:', stdout);
} else {
  console.error('Error:', stderr);
}

Working Directory and Environment

import { spawn } from '@dephub/spawn';

// Execute in specific directory
const result = await spawn('ls', ['-la'], {
  cwd: './src',
  env: { ...process.env, NODE_ENV: 'production' },
});

Streaming Output

import { spawnStream } from '@dephub/spawn';

// Stream npm install output to console
await spawnStream('npm', ['install'], {
  cwd: './project',
});

// Note: spawnStream returns only exit code, not stdout/stderr

Silent Execution

import { spawnSilent } from '@dephub/spawn';

// Capture output without inheriting stdio
const { stdout } = await spawnSilent('git', ['status']);
console.log('Git status:', stdout);

Fluent Builder API

import { SpawnBuilder } from '@dephub/spawn';

// Complex command with fluent API
const result = await new SpawnBuilder()
  .command('ffmpeg')
  .arg('-i')
  .arg('input.mp4')
  .arg('-c:v')
  .arg('libx264')
  .arg('output.mp4')
  .setOption('stdio', 'pipe')
  .setOption('encoding', 'utf8')
  .run();

Pre-configured Spawner

import { spawner } from '@dephub/spawn';

// Reusable spawner instance
const result = await spawner
  .command('docker')
  .arg('build')
  .arg('-t')
  .arg('my-app')
  .arg('.')
  .run();

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API Reference 📚

Core Functions

spawn(command, args?, options?)

Execute command with output capture (stdio: 'pipe' by default).

spawnSilent(command, args?, options?)

Execute with piped stdio and captured output.

spawnStream(command, args?, options?)

Execute with inherited stdio (output streamed to parent).

SpawnBuilder Class

Fluent API for building commands:

• .command(cmd) - Set command to execute
• .arg(arg) - Add command argument
• .setOption(key, value) - Set spawn option
• .run() - Execute and return result

Types

SpawnOptions

Extends Node.js SpawnOptions with:

• encoding - Character encoding for stdout/stderr

SpawnResult

• code - Exit code (0 for success)
• stdout - Captured stdout output
• stderr - Captured stderr output

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Common Patterns 🎨

Error Handling

import { spawn } from '@dephub/spawn';

try {
  const result = await spawn('unknown-command');
} catch (error) {
  console.error('Process failed:', error.message);
}

Working with Promises

import { spawn } from '@dephub/spawn';

spawn('ls', ['-la'])
  .then((result) => console.log(result.stdout))
  .catch((error) => console.error('Error:', error));

Batch Operations

import { spawn } from '@dephub/spawn';

const commands = [
  ['ls', ['-la']],
  ['pwd', []],
  ['whoami', []],
];

const results = await Promise.all(
  commands.map(([cmd, args]) => spawn(cmd, args)),
);

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Integration Examples 🔗

With Build Tools

import { spawnStream } from '@dephub/spawn';

async function buildProject() {
  await spawnStream('npm', ['run', 'build']);
  await spawnStream('npm', ['test']);
  await spawnStream('npm', ['run', 'lint']);
}

With File System Operations

import { spawn } from '@dephub/spawn';
import { readFile } from '@dephub/read';

const { stdout } = await spawn('git', ['log', '--oneline']);
const commits = stdout.split('\n').filter(Boolean);

CLI Tools Integration

#!/usr/bin/env node
import { spawnStream } from '@dephub/spawn';

await spawnStream('docker', ['build', '-t', 'my-app', '.']);
await spawnStream('docker', ['push', 'my-app']);

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Migration from Child Process

Before (Node.js native)

import { spawn } from 'child_process';

const child = spawn('ls', ['-la'], { stdio: 'pipe' });

let stdout = '';
child.stdout.on('data', (data) => {
  stdout += data;
});

await new Promise((resolve) => {
  child.on('close', resolve);
});

After (@dephub/spawn)

import { spawn } from '@dephub/spawn';

const { stdout } = await spawn('ls', ['-la']);

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License 📄

MIT License – see LICENSE for details.

Author: Estarlin R (estarlincito.com)