Converting a string Map to and from an object

map_obj.js

// The following two function convert string Maps to and from objects:
// http://www.2ality.com/2015/08/es6-map-json.html

function strMapToObj(strMap) {
  let obj = Object.create(null);
  for (let [k,v] of strMap) {
    // We don’t escape the key '__proto__'
    // which can cause problems on older engines
    obj[k] = v;
  }
  return obj;
}

function objToStrMap(obj) {
  let strMap = new Map();
  for (let k of Object.keys(obj)) {
    strMap.set(k, obj[k]);
  }
  return strMap;
}