Command Line Interface

/**
 * Main CLI entry point
 * @param args - Command line arguments array
 * @returns Promise resolving when command completes
 */
function cli(args: string[]): Promise<void>;

import { cli } from "snowpack";

// Programmatic CLI usage
await cli(['node', 'snowpack', 'dev', '--port', '3000']);
await cli(['node', 'snowpack', 'build', '--verbose']);

snowpack init

// Equivalent programmatic usage
import { initCommand } from "snowpack/commands";
await initCommand({ config, lockfile });

snowpack prepare

// Equivalent programmatic usage  
import { preparePackages } from "snowpack";
await preparePackages({ config });

snowpack dev

// Equivalent programmatic usage
import { startServer } from "snowpack";
const server = await startServer({ config, lockfile });

snowpack build

// Equivalent programmatic usage
import { build } from "snowpack";
const result = await build({ config, lockfile });

snowpack add <package>
snowpack rm <package>

// Equivalent programmatic usage
import { addCommand, rmCommand } from "snowpack/commands";
await addCommand('react', { config, lockfile });
await rmCommand('lodash', { config, lockfile });

/**
 * CLI flags interface
 */
interface CLIFlags {
  /** Display help message */
  help?: boolean;
  /** Display version information */
  version?: boolean;
  /** Clear local cache before running */
  reload?: boolean;
  /** Specify project root directory */
  root?: string;
  /** Path to configuration file */
  config?: string;
  /** Environment variables to set */
  env?: string[];
  /** URLs/browsers to open */
  open?: string[];
  /** Enable HTTPS */
  secure?: boolean;
  /** Enable verbose logging */
  verbose?: boolean;
  /** Enable minimal logging */
  quiet?: boolean;
  /** Additional custom flags */
  [flag: string]: any;
}

# Display help information
snowpack --help
snowpack -h

# Display version information  
snowpack --version
snowpack -v

# Use custom config file
snowpack dev --config ./custom.config.js

# Set project root
snowpack build --root ./my-app

# Clear cache before running
snowpack dev --reload

# Verbose logging (show debug information)
snowpack build --verbose

# Quiet logging (minimal output)
snowpack build --quiet

# Custom port
snowpack dev --port 8080

# Custom hostname
snowpack dev --hostname 0.0.0.0

# Enable HTTPS
snowpack dev --secure

# Open in browser
snowpack dev --open chrome
snowpack dev --open "google chrome"

# Set environment variables
snowpack dev --env NODE_ENV=development --env DEBUG=true

# Watch mode (rebuild on changes)
snowpack build --watch

# Custom output directory
snowpack build --out ./dist

# Clean output directory
snowpack build --clean

# Generate source maps
snowpack build --sourcemap inline

// Basic command structure
export async function commandName(commandOptions: CommandOptions) {
  try {
    const { config, lockfile } = commandOptions;
    
    // Command-specific logic here
    await performCommandLogic(config, lockfile);
    
  } catch (error) {
    logger.error(error.message);
    logger.error(error.stack);
    process.exit(1);
  }
}

# Example error output
❌ Build failed: Configuration validation error
   → Missing required field "mount" in snowpack.config.js
   → See https://snowpack.dev/reference/configuration

❌ Development server failed to start
   → Port 3000 is already in use
   → Try using --port flag with a different port number

// CLI configuration loading process
const cliFlags = parseArgs(args);
const cliConfig = expandCliFlags(cliFlags);
const config = await loadConfiguration(cliConfig, cliFlags.config);

# Full name
snowpack dev

# Short alias
sp dev

# Check Node.js version
node --version  # Must be 10.19.0 or higher

# Using npm scripts
npm run dev     # "dev": "snowpack dev"
npm run build   # "build": "snowpack build"

# Using yarn
yarn dev
yarn build

# Using pnpm  
pnpm dev
pnpm build

# Set via CLI
snowpack dev --env NODE_ENV=development

# Set in shell
export NODE_ENV=development
snowpack dev

# Public variables (available in browser)
export SNOWPACK_PUBLIC_API_URL=https://api.example.com

# Override config file location
export SNOWPACK_CONFIG=./custom.config.js

# Set cache directory
export SNOWPACK_CACHE_DIR=./custom-cache

# Check exit code in scripts
snowpack build
if [ $? -eq 0 ]; then
  echo "Build successful"
else
  echo "Build failed"
  exit 1
fi

# GitHub Actions example
- name: Build with Snowpack
  run: |
    npm ci
    npx snowpack build --verbose
    
# Docker example
RUN npm ci && npm run build

# Development setup
npm install
snowpack prepare  # Optional: pre-install dependencies
snowpack dev      # Start development server

# Production build
snowpack build
snowpack build --watch  # Watch mode for testing

{
  "scripts": {
    "start": "snowpack dev",
    "build": "snowpack build",
    "build:watch": "snowpack build --watch",
    "clean": "snowpack build --clean",
    "prepare": "snowpack prepare"
  }
}