yargs-unparser

yargs-unparser

Converts back a yargs argv object to its original array form.

Probably the unparser word doesn't even exist, but it sounds nice and goes well with yargs-parser.

The code originally lived in MOXY's GitHub but was later moved here for discoverability.

Installation

$ npm install yargs-unparser

Usage

const parse = require('yargs-parser');
const unparse = require('yargs-unparser');

const argv = parse(['--no-boolean', '--number', '4', '--string', 'foo'], {
    boolean: ['boolean'],
    number: ['number'],
    string: ['string'],
});
// { boolean: false, number: 4, string: 'foo', _: [] }

const unparsedArgv = unparse(argv);
// ['--no-boolean', '--number', '4', '--string', 'foo'];

The second argument of unparse accepts an options object:

• alias: The aliases so that duplicate options aren't generated
• default: The default values so that the options with default values are omitted
• command: The command first argument so that command names and positional arguments are handled correctly

Example with command options

const yargs = require('yargs');
const unparse = require('yargs-unparser');

const argv = yargs
    .command('my-command <positional>', 'My awesome command', (yargs) =>
        yargs
        .option('boolean', { type: 'boolean' })
        .option('number', { type: 'number' })
        .option('string', { type: 'string' })
    )
    .parse(['my-command', 'hello', '--no-boolean', '--number', '4', '--string', 'foo']);
// { positional: 'hello', boolean: false, number: 4, string: 'foo', _: ['my-command'] }

const unparsedArgv = unparse(argv, {
    command: 'my-command <positional>',
});
// ['my-command', 'hello', '--no-boolean', '--number', '4', '--string', 'foo'];

Caveats

The returned array can be parsed again by yargs-parser using the default configuration. If you used custom configuration that you want yargs-unparser to be aware, please fill an issue.

If you coerce in weird ways, things might not work correctly.

Tests

$ npm test
$ npm test -- --watch during development

Supported Node.js Versions

Libraries in this ecosystem make a best effort to track Node.js' release schedule. Here's a post on why we think this is important.

License

MIT License

Similar packages

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minimist

Minimist is a library for parsing command-line arguments. Unlike yargs-unparser, it does not unparse arguments but is commonly used for the initial parsing step that yargs-unparser would reverse.

commander

Commander is a complete solution for node.js command-line interfaces. It is similar to yargs in that it helps with parsing arguments, but it does not have a built-in feature to unparse them like yargs-unparser.

arg

Arg is a simple argument parsing library with a focus on performance. It does not have the unparse functionality but serves a similar initial purpose of parsing command-line arguments.