Source Code from ThermoCLI - refatorado by Suissinha

thermoCLI.js

#!/usr/bin/env node

'use strict';

const program = require('commander');

program
  .version('0.1.5')
  .usage('[options] <number>')
  .option('--c2f', 'convert Celsius to Fahrenheit')
  .option('--c2k', 'convert Celsius to Kelvin')
  .option('--f2c', 'convert Fahrenheit to Celsius')
  .option('--f2k', 'convert Fahrenheit to Kelvin')
  .option('--k2c', 'convert Kelvin to Celsius')
  .option('--k2f', 'convert Kelvin to Fahrenheit')

program.on('--help', () =>
  console.log(`  Example:

    $ thermo --c2f 32
    
    Converting 32 Celsius to Fahrenheit is equals to 89.6 Fahrenheit'

  `)
)

program.parse(process.argv);

const logResponse = ( num, start, end, converted ) =>   
  console.log(`   
              Converting ${num} ${start} to ${end} is equals to ${converted} ${end}

            `)
 
const OPTIONS = [ 'c2f', 'c2k', 'f2c', 'f2k', 'k2c', 'k2f' ]

const ACTIONS = {
  c2f: ( num ) => logResponse( num, 'Celsius', 'Fahrenheit', num * 1.8 + 32 ), 
  c2k: ( num ) => logResponse( num, 'Celsius', 'Kelvin', num + 273.15 ),
  f2c: ( num ) => logResponse( num, 'Fahrenheit', 'Celsius', (num - 32) / 1.8 ),  
  f2k: ( num ) => logResponse( num, 'Fahrenheit', 'Kelvin', (num - 32) * 5 / 9 + 273.15 ),  
  k2c: ( num ) => logResponse( num, 'Kelvin', 'Celsius', num - 273.15),  
  k2f: ( num ) => logResponse( num, 'Kelvin', 'Fahrenheit', num * 1.8 - 459.67), 
}

const keys = Object.keys( program )
const option = keys[ keys.length - 2 ]

ACTIONS[ option ]( parseFloat( program.args[0] ) )