diff.js

var deep = require('json-diff')

var oldConfig = require(process.argv[2]);
var newConfig = require(process.argv[3]).localConfigurationKeys;

var x = deep.diffString(oldConfig, newConfig);

console.log(x);

package.json

{
  "name": "test",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "dependencies": {
    "json-diff": "^0.3.1"
  },
  "devDependencies": {},
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC"
}