oppa

import { oppa } from 'oppa'; const cliArgs = process.argv.slice(2); // Get actual CLI arguments const parser = oppa({ name: 'myapp', version: '1.2.3', usage: 'myapp [options] <files...>', description: 'A utility for file operations.', noExit: true, // Prevent process exit for better testing/embedding throwOnError: true // Throw errors instead of printing help and exiting }) .add({ name: 'file', alias: 'f', type: 'string', description: 'The primary file to process.', defaultValue: 'default.txt' }) .add({ name: 'retry', alias: 'r', type: 'number', description: 'Number of retries before failing.', defaultValue: 3, validator: (v: number) => v >= 0 }) .add({ name: 'force', type: 'boolean', defaultValue: false, description: 'Force operation, overwriting existing files.' }) .add({ name: 'verbose', alias: 'v', type: 'boolean', description: 'Enable verbose logging.', noHelpAlias: true // Allows -v to be used here, if --version is also noVersionAlias }); try { const result = parser.parse(cliArgs); if (result.args.force) { console.log('Force mode enabled.'); } console.log(`Processing file: ${result.args.file}`); console.log(`Retries configured: ${result.args.retry}`); if (result.rest.length > 0) { console.log(`Additional files: ${result.rest.join(', ')}`); } // Example of accessing type-safe properties // result.args.retry.toFixed(0); // This is type-safe due to 'type: number' } catch (error) { if (error instanceof Error) { console.error(`CLI Error: ${error.message}`); } else { console.error('An unknown CLI error occurred.'); } parser.showHelp(); // Show help on error if throwOnError is true process.exit(1); }