9.4 KiB
9.4 KiB
Commander.js Options and Arguments Demo
Comprehensive examples of option and argument patterns.
Option Patterns
1. Boolean Flags
program
.command('build')
.option('-w, --watch', 'watch for changes')
.option('-m, --minify', 'minify output')
.option('-v, --verbose', 'verbose logging')
.action((options) => {
console.log('Watch:', options.watch); // true or undefined
console.log('Minify:', options.minify);
console.log('Verbose:', options.verbose);
});
Usage:
mycli build --watch --minify
2. Options with Required Values
program
.command('deploy')
.option('-e, --env <environment>', 'deployment environment')
.option('-r, --region <region>', 'AWS region')
.action((options) => {
console.log('Environment:', options.env);
console.log('Region:', options.region);
});
Usage:
mycli deploy --env production --region us-west-2
3. Options with Optional Values
program
.command('log')
.option('-f, --file [path]', 'log file path')
.action((options) => {
if (options.file === true) {
console.log('Using default log file');
} else if (options.file) {
console.log('Log file:', options.file);
}
});
Usage:
mycli log --file # file = true
mycli log --file custom.log # file = 'custom.log'
mycli log # file = undefined
4. Options with Defaults
program
.command('serve')
.option('-p, --port <port>', 'port number', '3000')
.option('-h, --host <host>', 'hostname', 'localhost')
.action((options) => {
console.log(`http://${options.host}:${options.port}`);
});
Usage:
mycli serve # Uses defaults
mycli serve --port 8080 # Custom port
5. Negatable Options
program
.command('build')
.option('--cache', 'enable cache')
.option('--no-cache', 'disable cache')
.option('--color', 'enable colors')
.option('--no-color', 'disable colors')
.action((options) => {
console.log('Cache:', options.cache); // undefined, true, or false
console.log('Color:', options.color);
});
Usage:
mycli build # cache & color = undefined
mycli build --cache # cache = true
mycli build --no-cache # cache = false
mycli build --no-color # color = false
6. Variadic Options
program
.command('tag')
.option('-t, --tags <tags...>', 'multiple tags')
.action((options) => {
console.log('Tags:', options.tags); // Array
});
Usage:
mycli tag --tags v1.0 production stable
# Tags: ['v1.0', 'production', 'stable']
7. Options with Custom Parsers
program
.command('scale')
.option('-r, --replicas <count>', 'replica count', parseInt)
.option('-m, --memory <mb>', 'memory in MB', parseFloat)
.option('-t, --timeout <sec>', 'timeout', (value) => {
return parseInt(value) * 1000; // Convert to ms
})
.action((options) => {
console.log('Replicas:', options.replicas); // Number
console.log('Memory:', options.memory); // Number
console.log('Timeout:', options.timeout); // Number (ms)
});
Usage:
mycli scale --replicas 5 --memory 512.5 --timeout 30
Argument Patterns
1. Required Arguments
program
.command('deploy <environment>')
.description('Deploy to environment')
.action((environment) => {
console.log('Deploying to:', environment);
});
Usage:
mycli deploy production # ✓ Works
mycli deploy # ✗ Error: missing required argument
2. Optional Arguments
program
.command('create <name> [description]')
.description('Create item')
.action((name, description) => {
console.log('Name:', name);
console.log('Description:', description || 'No description');
});
Usage:
mycli create "My Item"
mycli create "My Item" "A detailed description"
3. Variadic Arguments
program
.command('add <items...>')
.description('Add multiple items')
.action((items) => {
console.log('Items:', items); // Array
items.forEach((item, i) => {
console.log(` ${i + 1}. ${item}`);
});
});
Usage:
mycli add item1 item2 item3
# Items: ['item1', 'item2', 'item3']
4. Mixed Required and Optional
program
.command('copy <source> <destination> [options]')
.description('Copy files')
.action((source, destination, options) => {
console.log('Source:', source);
console.log('Destination:', destination);
console.log('Options:', options || 'none');
});
5. Arguments with Descriptions
program
.command('deploy <environment>')
.argument('<environment>', 'target environment (dev, staging, prod)')
.argument('[region]', 'deployment region', 'us-east-1')
.action((environment, region) => {
console.log(`Deploying to ${environment} in ${region}`);
});
6. Arguments with Custom Parsers
program
.command('wait <seconds>')
.argument('<seconds>', 'seconds to wait', parseFloat)
.action(async (seconds) => {
console.log(`Waiting ${seconds} seconds...`);
await new Promise((resolve) => setTimeout(resolve, seconds * 1000));
console.log('Done!');
});
Usage:
mycli wait 2.5 # Waits 2.5 seconds
7. Arguments with Validation
program
.command('set-port <port>')
.argument('<port>', 'port number', (value) => {
const port = parseInt(value, 10);
if (isNaN(port)) {
throw new Error('Port must be a number');
}
if (port < 1 || port > 65535) {
throw new Error('Port must be between 1 and 65535');
}
return port;
})
.action((port) => {
console.log('Port set to:', port);
});
Combined Patterns
Arguments + Options
program
.command('deploy <environment>')
.argument('<environment>', 'deployment environment')
.option('-f, --force', 'force deployment')
.option('-d, --dry-run', 'simulate deployment')
.option('-t, --tag <tag>', 'deployment tag', 'latest')
.action((environment, options) => {
console.log('Environment:', environment);
console.log('Force:', options.force);
console.log('Dry run:', options.dryRun);
console.log('Tag:', options.tag);
});
Usage:
mycli deploy production --force --tag v1.2.3
Variadic Arguments + Options
program
.command('compile <files...>')
.argument('<files...>', 'files to compile')
.option('-o, --output <dir>', 'output directory', './dist')
.option('-m, --minify', 'minify output')
.action((files, options) => {
console.log('Files:', files);
console.log('Output:', options.output);
console.log('Minify:', options.minify);
});
Usage:
mycli compile src/a.ts src/b.ts --output build --minify
Multiple Option Types
program
.command('start')
.option('-p, --port <port>', 'port', '3000')
.option('-h, --host <host>', 'host', 'localhost')
.option('-o, --open', 'open browser')
.option('--no-color', 'disable colors')
.option('-e, --env <vars...>', 'environment variables')
.action((options) => {
console.log('Server:', `http://${options.host}:${options.port}`);
console.log('Open:', options.open);
console.log('Color:', options.color);
console.log('Env:', options.env);
});
Usage:
mycli start --port 8080 --open --env NODE_ENV=production DEBUG=true
Complete Example
#!/usr/bin/env node
import { Command } from 'commander';
import chalk from 'chalk';
const program = new Command();
program.name('deploy-cli').version('1.0.0');
program
.command('deploy <environment> [region]')
.description('Deploy application')
.argument('<environment>', 'target environment (dev, staging, prod)')
.argument('[region]', 'deployment region', 'us-east-1')
.option('-f, --force', 'skip confirmations', false)
.option('-d, --dry-run', 'simulate deployment', false)
.option('-t, --tag <tag>', 'deployment tag', 'latest')
.option('-r, --replicas <count>', 'replica count', parseInt, 3)
.option('--env <vars...>', 'environment variables')
.option('--no-rollback', 'disable auto-rollback')
.action((environment, region, options) => {
console.log(chalk.blue('Deployment Configuration:'));
console.log('Environment:', chalk.yellow(environment));
console.log('Region:', region);
console.log('Tag:', options.tag);
console.log('Replicas:', options.replicas);
console.log('Force:', options.force);
console.log('Dry run:', options.dryRun);
console.log('Rollback:', options.rollback);
if (options.env) {
console.log('Environment variables:');
options.env.forEach((v) => console.log(` ${v}`));
}
if (options.dryRun) {
console.log(chalk.yellow('\n🔍 Dry run - no actual deployment'));
return;
}
console.log(chalk.green('\n✓ Deployment complete!'));
});
program.parse();
Usage examples:
# Basic
deploy-cli deploy production
# With region
deploy-cli deploy staging us-west-2
# With options
deploy-cli deploy prod --force --replicas 5
# With environment variables
deploy-cli deploy prod --env NODE_ENV=production API_KEY=xyz
# Dry run
deploy-cli deploy prod --dry-run --no-rollback
# All together
deploy-cli deploy production us-west-2 \
--force \
--tag v2.0.0 \
--replicas 10 \
--env NODE_ENV=production DEBUG=false \
--no-rollback