$ npm install --save getter.js

var dataObj = {
  test: 'testString',
  test2: 'testString2',
  getTest: () => {
    const self = this;
    return new Promise(resolve => resolve(self.test));
  },
  getTest2: () => {
    const self = this;
    return new Promise(resolve => resolve(self.test2));
  }
}

dataObj
  .getTest()
  .then(response => console.log(response));

import getter from 'getter.js'

let dataObj = {
  test: 'testString',
  test2: 'testString2'
};
dataObj = getter(dataObj);

const asyncTestValue = await dataObj.getTest();


let config = {
  async: false,
  multiple: false
};
dataObj = getter(dataObj, config);
const testValue = dataObj.get('test');