basic-args

Basic argument parsing library using yargs-parser with built-in help screen

Installation

npm install basic-args

Usage

See index.d.ts for API

CommonJS import

const args = require('basic-args')({
  name: 'basic-args-example',
  version: '1.0.0',
  description: 'A basic example of basic-args',
  errorOnUnknown: true,
  options: {
    version: { type: String, description: 'Version to connect as', alias: 'v' },
    port: { type: Number, description: 'Port to listen on', default: 25565 },
    online: { type: Boolean, description: 'Whether to run in online mode' },
    path: { type: String, description: 'Path to the server directory', default: '.' }
  }
})

console.log(args)

After being ran with node index.js --version 1.16 (or using -v 1.16 alias) we would get:

{ version: '1.16.1', port: 25565, online: false, path: '.' }

Please note Boolean options do not need arguments, simply passing them as an argument will resolve them to be true. If you want to force an argument, set type to a String to handle yourself.

Extraneous arguments (when not using errorOnExtra) are stored in the _ index of the output. The nested _ contains positionals.

Help screen

If we run with --help or get a argument error, we see the help screen:

> node example.js --help   
basic-args-example - v1.0.0
A basic example of basic-args

Options:
  --version     Version to connect as
  --port        Port to listen on  (default: 25565)
  --online      Whether to run in online mode
  --path        Path to the server directory  (default: .)

Custom args

The second argument is the custom arg array if any, if it's not set, we default to process.argv.

require('basic-args')(options, process.argv)

ES6 import

import basicArg from 'basic-args'
const args = basicArg({
  name: 'basic-args-example',
  version: '1.0.0',
  description: 'A basic example of basic-args',
  throwOnError: false, // Throw an error instead of calling process.exit() with help screen (default: false)
  helpCommand: 'help', // The -- command for opening the built-in help screen (default: help)
  options: {
    version: { type: String, description: 'Version to connect as', alias: 'v' },
    port: { type: Number, description: 'Port to listen on', default: 25565 },
    online: { type: Boolean, description: 'Whether to run in online mode' },
    path: { type: String, description: 'Path to the server directory', default: '.' }
  },
  // validate (args) { return true } /* optional fn to verify the args before returning them; non-true return value will print help screen */
})
// ...

Testing

npm test

History

See history