CLI Developer

Use Commander.js for argument parsing and cosmiconfig for config file resolution:

npm install commander cosmiconfig chalk ora

// src/cli.ts
import { Command } from 'commander';
import { cosmiconfig } from 'cosmiconfig';

const program = new Command();

program
  .name('mytool')
  .version('1.0.0')
  .description('Deployment management tool');

// Global option available to all subcommands
program.option('--config <path>', 'path to config file');

program
  .command('deploy')
  .description('Deploy to the target environment')
  .argument('<environment>', 'Target environment (staging|production)')
  .option('--dry-run', 'Preview changes without applying')
  .action(async (environment, options, cmd) => {
    const config = await loadConfig(cmd.parent?.opts().config);
    await deployCommand(environment, options, config);
  });

program
  .command('rollback')
  .description('Roll back the last deployment')
  .option('--steps <n>', 'Number of versions to roll back', '1')
  .action(async (options, cmd) => {
    const config = await loadConfig(cmd.parent?.opts().config);
    await rollbackCommand(parseInt(options.steps), config);
  });

async function loadConfig(configPath?: string) {
  const explorer = cosmiconfig('mytool'); // looks for .mytoolrc, mytool.config.js, etc.
  const result = configPath
    ? await explorer.load(configPath)
    : await explorer.search();
  if (!result) throw new Error('No config file found. Run `mytool init` to create one.');
  return result.config;
}

program.parseAsync(process.argv);

File structure:

src/
  cli.ts          # entry point, command tree
  commands/
    deploy.ts     # deploy logic
    rollback.ts   # rollback logic
  lib/
    config.ts     # config loading
    api.ts        # API client

package.json bin field:

{ "bin": { "mytool": "./dist/cli.js" } }

Users run npm install -g mytool and get the mytool command in their PATH.