Proportional

Proportional is a library for CLI tools intended to make users having a better time. Many new users struggle when starting with advanced tools or tools in general, most likely due the complexity of many tools out there today.

A common approach to this problem is 0CJS. It consists of only requiring the bare minimum for users to use the tool you have created. This tool is an extention of that. By gradually adapting the CLI for users over time or by invoking a command, the developer experience could become better over time.

Usage

The library exposes a simple interface derived from yargs. By using yargs's convention when creating your CLI, you will be able to create a CLI within a simple scope of yargs. Not all methods from yargs methods are supported.

Installation

Using npm

$ npm install --save proportional

Using yarn

$ yarn add proportional

Example

const Proportional = require('proportional');

const CLI = new Proportional();

CLI.levels(['webpagetest', 'lighthouse', 'psi']);

CLI.threshold({
  webpagetest: 1,
  lighthouse: 2,
  psi: 3,
});

CLI.hook({
  webpagetest: () => require('./node_modules/.bin/webpagetest'),
  lighthouse: () => require('./node_modules/.bin/lighthouse'),
  psi: () => require('./node_modules/.bin/psi'),
});

CLI.run(process.argv.slice(2));

More examples are found in the examples directory.

API

threshold

Threshold is a way to specify how many times the current CLI should be used before it should switch to another higher alternative. By setting the threshold, you could allow users to gradually shift towards a more complex CLI over time.

const Proportional = require('proportional');
const CLI = new Proportional();

CLI.threshold({
  levelOne: 10,
  levelTwo: 20,
  levelThree: 30,
});

usage

Usage works as it does with yargs. The usage option is visible when the user types a wrong command and it accepts an object.

const Proportional = require('proportional');
const CLI = new Proportional();

CLI.usage({
  levelOne: 'Seems like you missed the init option! try again with init!',
  levelTwo: 'Ipsum Lorem',
  levelThree: 'This is way to advanced'
});

version

Pass the version number to be used when outputting the help flag.

const Proportional = require('proportional');
const CLI = new Proportional();

CLI.version({
  levelOne: '1.2.3',
  levelTwo: '4.5.6',
  levelThree: '8.9.10'
});

CLI.version('1.34.5');

levels

By setting levels, you specify which CLI should be run. In order for the tool to know which cli to change to, you need to match this option(array) with threshold and/or hook.

const Proportional = require('proportional');
const CLI = new Proportional();

CLI.levels(['levelOne', 'levelTwo', 'levelThree']);

defaultLevel

You can specify a default level for your tool to start using.

const Proportional = require('proportional');
const CLI = new Proportional();

CLI.levels(['levelOne', 'levelTwo', 'levelThree']);
CLI.defaultLevel('levelOne');

hook

This option allows you to tap into other CLI's when creating your tool. The function expects an object with the keys being your levels and the value being the module you are going to use. This tool handles process.env for you, so if you combine the tool with arguments that are supported in this libary, it will not be used in the module you are using.

const Proportional = require('proportional');
const CLI = new Proportional();

CLI.hook({
  levelOne: () => require('./node_modules/.bin/easy'),
  levelTwo: () => require('./node_modules/.bin/medium'),
  levelThree: () => require('./node_modules/.bin/hard'),
});

alias

Alias works as yargs handles aliases. You can either supply it through options, or with an own flag.

CLI.alias({
  k: 'k',
  p: 'p'
});

options

Options are handled the same way as yargs handles an option, however, this follows the key/value convention where you need to pass the level as the key and the option to be the value.

const Proportional = require('proportional');
const CLI = new Proportional();

CLI.options({
  levelOne: {
    alright: {
      type: 'boolean',
      alias: 'a',
      describe: 'AaA?',
    },
    bC00l: {
      type: 'boolean',
      describe: 'B c00l :)',
    },
  },
  levelTwo: {...}
})

upgrade

If you want to switch to another CLI at runtime you can use the upgrade flag, or use the built in function to do it at "compile-time".

If you use the function, you can either supply a string(being the level you want to change to), or call the function without any arguments, where the tool will read your .proportional configuration to determine which CLI to swap to.

const Proportional = require('proportional');
const CLI = new Proportional();

CLI.upgrade("levelOne");

const Proportional = require('proportional');
const CLI = new Proportional();

CLI.upgrade();

$ node ./my/path.js upgrade --help

downgrade

Downgrade works similarly as upgrade.

const Proportional = require('proportional');
const CLI = new Proportional();

CLI.downgrade("levelOne");

const Proportional = require('proportional');
const CLI = new Proportional();

CLI.downgrade();

$ node ./my/path.js downgrade --help

run

To run the CLI, you will need to invoke the run method. If you built the tool using options, aliases et al. from proportional, output and argv is given back to you. If you use hooks, nothing is returned. To handle both cases (hooks and your own CLI), see examples/webpack.

const Proportional = require('proportional');
const CLI = new Proportional();

// or const results = CLI.run(process.argv.slice(2))
CLI.run(process.argv.slice(2));

misc

You can also pass the level to the CLI you want to swap to if you want to. If you have set the level thisLevel programatically, but your current level is previousLevel you can swap to the level by calling node ./path/to/myCLI.js thisLevel <args>.

$ node ./my/path.js levelTwo --help

evenstensberg/proportional