vrc

vrc

This is a configuration loader based on rc, extended by argument validation and --help.

const { Vrc } = require( 'vrc' );

const conf = new Vrc( 'myAppName', [
    { name: 'name', dflt: 'Jack', desc: 'Name to print', type: 'string' },
], { description: 'This tool solves any problem given' } ).run();

console.log( `Name: ${conf.get('name')}` );

Automatic help shows default values and actually used values.

Configuration

vrc( appName, conf ) : { conf, invalidNames }

Returns the conf object from rc and a list of invalid names where the user supplied wrong parameters (e.g. string instead of number). Invalid values will be replaced by their defaults.

A configuration entry takes the following arguments:

• name: Name of the variable/parameter
• desc: Description, shown in the help
• dflt: Default value
• type: Supported values: 'string', 'number', 'boolean', number[], number[][]
• options: Array holding valid options for the argument. Currently only for strings.

Number arrays are passed as comma-separated values and are converted; 1,3,42 results in [1,3,42].

TypeScript usage

Vrc can be used with limited typing support by passing an interface to the constructor.

import { Vrc } from 'vrc';

interface Conf {
    balloons : number;
    colour : string;
}

const conf = new Vrc<Conf>( 'balloon', [
    { name: 'balloons', type: 'number', dflt: 99, desc: 'Number of balloons' },
    { name: 'colour', type: 'string', dflt: 'red', desc: 'Balloon colour' },
] ).run();

console.log( conf.conf.balloons ); // 99

Changelog

v2.8.0 – 2025-03-26

• Changed: Vrc now has class and constructor documentation to simplify coding.
• Breaking: VrcConf renamed to Vrc – this is only relevant if you imported the vrc-conf.js file instead of the module, which still exports Vrc. The preferred import way remains import { Vrc } from 'vrc'; for TypeScript, or const Vrc = require('rvc'); for JavaScript.

v2.7.1 – 2024-10-29

• Update dependencies

v2.7.0 – 2024-06-11

• Added: VrcSettings accept an additionalHelp callback function which, if defined, can print additional help text which is shown on --help.

  const conf = new VrcConf( 'foo', [], { additionalHelp: () => 'More details' } );
  

• Changed: braces dependency updated

v2.6.0 – 2024-05-19

• Breaking: Constructor throws an error if an argument starts with no- because this is used as a prefix for negated boolean arguments by rc. (If this causes issues, please open an issue on GitHub.)

v2.5.3 – 2024-04-09

• Update dependencies

v2.5.2 – 2022-04-05

• Update dependencies

v2.5.1 – 2022-02-01

• Update dependencies

v2.5.0 – 2021-09-20

• Revert TypeScript changes from 2.4.0
• Update dependencies

v2.3.0 – 2020-07-22

• Add support for options to number type parameter
• Default arguments are validated against options

v2.2.0 – 2020-06-27

• Convert Numbers to string for string parameters

v2.1.3 – 2020-05-11

• Update dependencies and correct changelog

v2.1.2 – 2020-05-11

• Changed help output to redact user-provided secrets

v2.1.1 – 2020-04-03

• Update minimist dependency to fix audit issue

v2.1.0 – 2020-04-02

This version fixes the way arguments are marked as invalid and does not replace invalid user arguments by default values anymore as this is potentially dangerous.

• Added VrcConf.unnamedArgs which contains positional/unnamed arguments
• Added VrcConf.printArgs() to print a summary of all arguments
• Added the secr modifier for arguments which causes them not to be printed with the above function
• Breaking: Invalid arguments are not replaced by default values anymore.

v2.0.0 – 2020-03-03

• Breaking: Configuration is now created with new Vrc() which can be typed in TypeScript.
• Breaking: To evaluate the help parameter, use new Vrc().run().
• Removed: VrcConf.invalidNames

v1.11.0 – 2020-03-03

• Added: vrc now returns a VrcConf object which can e.g. check if an argument is using a default value or a user-provided value. The object is backwards compatible and still exhibits the old properties.

v1.10.0 – 2020-03-02

• Added options for string parameters to define possible values

v1.9.0 – 2020-02-10

• Changed: Long description lines are now wrapped in the help output.

v1.8.0 – 2020-01-08

• Added support for string[]