yaro v7

A companion to Hela. Fast, minimalist, pluggable and functional command line parsing. Create CLIs easily. A wrapper package exporting everything from several Yaro packages. Creating CLI programs, easily. Deno support and ESM-only default. Similar to CAC, Yargs, and Sade, because there are different problems and viewpoints.

NOTE: this is ESM-only package

Highlights

• Familiar and small APIs.
• Built from the ground up, for N-th time.
• Used in production for years.
• Stable & robust
• Single Command Mode support.
• Built-in help output & version.
• Checking for option's value.
• Missing required arguments checking.
• Sane defaults, option's value type checking too.
• Veriadic and positional arguments.
• Familiar & intuitive sub-commands support.
• Dot-notation, camelCase options, and other goodies.
• ESM-only (& node >=20) & Deno support ('https://esm.sh/yaro@6/src/index.js').
• Total composition - every command built is just a function on steroids!

More docs and better help output - soon!

But it's pretty straightforward:

• yaroCommand(rawName) => cli
• cli.option(rawName, desc, config = {})
• cli.alias(...aliases)
• cli.version(versionString)
• cli.action(async (flags, ...args) => {})
• cli.describe(desc) - add description to a command! Useful for single command mode.

Example

Making a git-like cli:

import { yaro, yaroCommand } from 'yaro';

// node ./examples/git-like.js --help

// node ./examples/git-like.js --help

// `commit` is just an async function
// NOTE: arguments are passed as second param to the handler, as named params
const commit = yaroCommand('commit [...msg]', async (_options, { msg }) => {
  console.log('git commit -sS', JSON.stringify(msg.flat().join(' ')));
});

// `add` is just an async function
const add = yaroCommand('add [...files]', 'git add files')
  .option('-A, --all', 'add all files', true)
  .action(async (_options, { files }) => {
    console.log('git add files:', files);
  });

// `remoteAdd` is just an async function
// NOTE: optional arguments can have default values
const remoteAdd = yaroCommand('remote add [foo] [bar=qux]')
  .option('-f, --force', 'some option here')
  .option('--dry-run', 'Call without running', false)
  .action(async (_options, { foo, bar }, commandMeta) => {
    console.log('adding remote %s -> %s', foo, bar, { commandMeta });
  });

// git remote rm foo
// git remote del foo
// git remote remove foo
// git rerm foo
const remoteDelete = yaroCommand('remote rm <name>')
  .alias('remote del', 'remote remove', 'rerm')
  .option('--dry-run', 'Call without running', false)
  .action(async (options, { name }) => {
    console.log('git remote rm', name);

    if (!options.foo) {
      throw new Error('some fake random error, try passing --foo');
    }

    console.log('okkkk! foo is passed');
  });

await yaro.run({
  name: 'git-cli',
  version: '3.1.1',
  showHelpOnEmpty: true,
  commands: {
    add,
    remoteAdd,
    remoteDelete,
    commit,
  },
});

Single Command Mode

We are detecting by default if you pass just one yaroCommand to the commands object of yaro.run. Or if you want this command to have more sub commands, pass both rootCommand and commands.

You can try this example with node examples/linter-cli.js foo bar qux

import proc from 'node:process';

import { run, isRequiredUtil, yaroCommand } from 'yaro';

// or Deno
// import { yaroCommand } from 'https://esm.sh/yaro@6'
const xaxa = yaroCommand(
  '[foo] [...files]',
  'Lint and format files with ESLint --fix and Prettier.',
)
  .option('--cwd', 'Working directory, defaults to `process.cwd()`.', proc.cwd())
  .option('--log', 'Log per changed file', false)
  .option('-f, --force', 'Force lint, cleaning the cache.', false)
  .option('-c, --config', 'Path to config file.', {
    default: 'xaxa.config.js',
    required: isRequiredUtil,
  })
  .option('--workspace-file', 'File path to write workspaces metadata.', {
    default: 'hela-workspace.json',
    required: isRequiredUtil,
    // type: 'string',
    // normalize: true,
  })
  .option('--verbose', 'Print more verbose output.', false)
  .action(async (flags, { files }) => {
    console.log('flags/options', flags);
    console.log('files passed', files);
    console.log('arguments', args);

    // await lint(files, flags);
  });

console.log({ xaxa });
// => {
//   xaxa: [AsyncFunction: commandAction] {
//     isYaroCommand: true,
//     cli: {
//       settings: [Object],
//       usage: '[foo] [...files]',
//       meta: [Object],
//       aliases: [],
//       alias: [Function (anonymous)],
//       option: [Function (anonymous)],
//       action: [Function (anonymous)],
//       name: '___UNNAMED_COMMAND-1',
//       args: [Array],
//       parts: [Array]
//     }
//   }
// }

// or import yaro, and call `yaro.run`
await run({
  commands: { xaxa },
  version: '3.2.1',
  name: 'xaxa-cli',
});