create-new-app/modules/portValidator.js

Easily generate a new React application, optionally with Express & MongoDB.

/*
  This module ensures that the various port values provided
  don't collide with eachother and that they are withing range.
*/

const chalk = require('chalk')

function portValidator(val, defaultPort) {
  const num = Number.isInteger(+val) ? +val : undefined

  if (num === undefined) {
    const msg = `\n"${val}" is an invalid port. Defaulting to ${defaultPort}...\n`
    console.log(chalk.yellow.bold(msg))
    return defaultPort
  }

  if (num < 1 || num > 65535) {
    const msg = `\n"${num}" is out of range (1 - 65535). Defaulting to ${defaultPort}...\n`
    console.log(chalk.yellow.bold(msg))
    return defaultPort
  }

  return num
}

module.exports = portValidator