Protect environment variables

protect-evironment-variables.js

function uFirst(v) {
  return v.length > 0 ? `${v[0].toUpperCase()}${v.substr(1)}` : "";
}

function toCamelCase(v) {
  return v
    .toLowerCase()
    .split("_")
    .map((e, i) => (i > 0 ? uFirst(e.trim()) : e.toLowerCase()))
    .join("");
}

var conf = null;
var exportedConf = null;

module.exports = (() => {
  if (exportedConf !== null) {
    return exportedConf;
  }
  conf = conf || {};
  // Clone basic env
  const cachedEnv = { ...process.env };
  // Load env file
  require("dotenv").config();
  let keys = Object.keys(process.env);
  // Copy data to private conf
  for (let i = 0; i < keys.length; i += 1) {
    let key = keys[i];
    conf[toCamelCase(key)] = process.env[key];
    // Delete all keys from .env file
    if (typeof cachedEnv[key] === "undefined") {
      delete process.env[key];
    }
  }
  exportedConf = new Proxy(conf, {
    get(target, prop, receiver) {
      if (typeof target[prop] !== "undefined") {
        return Reflect.get(target, prop, receiver);
      }
      throw new Error(`You are trying to access undefined key`);
    },
    set: () => {
      throw new Error(`You can not set value to immutable object`);
    },
    has: () => false,
    ownKeys: () => [],
  });
  return exportedConf;
})();