Treat ordinary object as Map: `keys(), values(), entries())`

mapy.js

function mapy(object, andPrototype, andAssign) {
   const _object = object;

   let _mapy = {
      keys() { return Object.keys(_object); },
      values() { return _it(true); },
      entries() { return _it(false); }
   }
   if (andPrototype)
      Object.setPrototypeOf(_mapy, object);
   if (andAssign)
      Object.assign(_mapy, object);

   return _mapy;

   function _it(justValues) {
      let idx = 0;
      const _keys = Object.keys(_object);

      return {
         [Symbol.iterator]() { return this; },

         next() {
            let done = idx >= _keys.length;
            if (done)
               return { value: undefined, done: true }
            else {
               let k = _keys[idx];
               let v = _object[_keys[idx]];
               let value = justValues ? v : [k,v];
               idx++;
               return { value, done }
            }
         }
      }
   }
}


const o = {a:1, b:2, c:3, foo: function() { console.log("foo"); }};
let m1 = mapy(o);
var x = Array.from(m1.keys()); console.dir(x);
x = Array.from(m1.values()); console.dir(x);
x = Array.from(m1.entries()); console.dir(x);
console.log(m1.a);

m1 = mapy(o, true, true);
console.log(m1.a);
m1.foo();