Yargs be a node.js library fer hearties tryin' ter parse optstrings
Yargs helps you build interactive command line tools, by parsing arguments and generating an elegant user interface.
It gives you:
my-program.js serve --port=5000).``` mocha [spec..]
Run tests with Mocha
Commands
mocha inspect [spec..] Run tests with Mocha [default]
mocha init
Rules & Behavior –allow-uncaught Allow uncaught errors to propagate [boolean] –async-only, -A Require all tests to use a callback (async) or return a Promise [boolean] ```
Stable version:
bash
npm i yargs
Bleeding edge version with the most recent features:
bash
npm i yargs@next
```javascript
const yargs = require(‘yargs/yargs’) const { hideBin } = require(‘yargs/helpers’) const argv = yargs(hideBin(process.argv)).argv
if (argv.ships > 3 && argv.distance < 53.5) { console.log(‘Plunder more riffiwobbles!’) } else { console.log(‘Retreat from the xupptumblers!’) } ```
```bash $ ./plunder.js –ships=4 –distance=22 Plunder more riffiwobbles!
$ ./plunder.js –ships 12 –distance 98.7 Retreat from the xupptumblers! ```
```javascript
const yargs = require(‘yargs/yargs’) const { hideBin } = require(‘yargs/helpers’)
yargs(hideBin(process.argv))
.command(‘serve [port]’, ‘start the server’, (yargs) => {
yargs
.positional(‘port’, {
describe: ‘port to bind on’,
default: 5000
})
}, (argv) => {
if (argv.verbose) console.info(start server on :${argv.port})
serve(argv.port)
})
.option(‘verbose’, {
alias: ‘v’,
type: ‘boolean’,
description: ‘Run with verbose logging’
})
.argv
```
Run the example above with --help to see the help for the application.
yargs has type definitions at @types/yargs.
npm i @types/yargs --save-dev
See usage examples in docs.
As of v16, yargs supports Deno:
```typescript import yargs from ‘https://deno.land/x/yargs/deno.ts’ import { Arguments } from ‘https://deno.land/x/yargs/deno-types.ts’
yargs(Deno.args) .command(‘download <files…>’, ‘download a list of files’, (yargs: any) => { return yargs.positional(‘files’, { describe: ‘a list of files to do something with’ }) }, (argv: Arguments) => { console.info(argv) }) .strictCommands() .demandCommand(1) .argv ```
As of v16,yargs supports ESM imports:
```js import yargs from ‘yargs’ import { hideBin } from ‘yargs/helpers’
yargs(hideBin(process.argv))
.command(‘curl
See examples of using yargs in the browser in docs.
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