const requireMaybe = require('require-maybe');
 
function noop(x) {
  return x
}
 
// use `rainbow` if it’s installed, or normal text if it isn't
const rainbow = requireMaybe('chalk-rainbow') || noop
console.log(rainbow('hello world!'))
// -> rainbowified or plain "hello world!"
 
 
// Use either implementation of `camelcase`, or none
const camelcase = requireMaybe(['lodash.camelcase', 'camelcase']) || noop
console.log(camelcase('hello world!'))
// -> "helloWorld!" or "hello world!"