Сравните вложенные объекты в JavaScript и верните равенство ключей

const isObject = v => v && typeof v === 'object';

function getDifference(a, b) {
    return Object.assign(...Array.from(
        new Set([...Object.keys(a), ...Object.keys(b)]),
        k => ({ [k]: isObject(a[k]) && isObject(b[k])
            ? getDifference(a[k], b[k])
            : a[k] === b[k]
        })
    ));
}

var obj1 = { prop1: 1, prop2: "foo", prop3: { prop4: 2, prop5: "bar" } },
    obj2 = { prop1: 3, prop2: "foo", prop3: { prop4: 2, prop5: "foobar" }, prop6: "new" };

console.info(getDifference(obj1, obj2));

const obj1 = {prop1:1,prop2:"foo",prop3:{prop4:2,prop5:"bar"},prop7:{pro8:"only in 1"}},
      obj2 = {prop1:3,prop2:"foo",prop3:{prop4:2,prop5:"foobar"}, prop6: "only in 2"};
    
const isObject = val => typeof val === 'object' && val // required for "null" comparison

function compare(obj1 = {}, obj2 = {}) {
  const output = {},
        merged = { ...obj1, ...obj2 }; // has properties of both

  for (const key in merged) {
    const value1 = obj1[key],
          value2 = obj2[key];

    if (isObject(value1) || isObject(value2))
      output[key] = compare(value1, value2) // recursively call
    else
      output[key] = value1 === value2
  }
  
  return output;
}

console.info(compare(obj1, obj2))

const obj1 = {"prop1":1,"prop2":"foo","prop3":{"prop4":2,"prop5":"bar"},"prop7":{"prop9":{"prop10":"foo"}}}
const obj2 = {"prop1":3,"prop2":"foo","prop3":{"prop4":2,"prop5":"foobar"},"prop6":"new","prop7":{"foo":"foo","bar":{"baz":"baz"}}}

function get(obj, path) {
  return path.split('.').reduce((r, e) => {
    if (!r) return r;
    else return r[e] || undefined;
  }, obj);
}

function isEmpty(o) {
  if (typeof o !== 'object') return true;
  else return !Object.keys(o).length;
}

function build(a, b, o = null, prev = '') {
  return Object.keys(a).reduce(
    (r, e) => {
      const path = prev + (prev ? '.' + e : e);
      const bObj = get(b, path);
      const value = a[e] === bObj;

      if (typeof a[e] === 'object') {
        if (isEmpty(a[e]) && isEmpty(bObj)) {
          if (e in r) r[e] = r[e];
          else r[e] = true;
        } else if (!bObj && isEmpty(a[e])) {
          r[e] = value;
        } else {
          r[e] = build(a[e], b, r[e], path);
        }
      } else {
        r[e] = value;
      }
      return r;
    },
    o ? o : {}
  );
}

function compare(a, b) {
  const o = build(a, b);
  return build(b, a, o);
}

const result = compare(obj1, obj2);
console.info(result)

var obj1 = {
        prop1: 1,
        prop2: "foo",
        prop3: {
            prop4: 2,
            prop5: "bar"
        },
        prop7: {},
    }

    var obj2 = {
        prop1: 3,
        prop2: "foo",
        prop3: {
            prop4: 2,
            prop5: "foobar"
        },
        prop6: "new",
        prop7: {},
        prop8: {},
    }

    var result = {};

    function compare(obj1, obj2, obj_) {
        for (let k in obj1) {
            var type = typeof obj1[k];
            if (type === 'object') {
                obj_[k] = {};
                if (!obj2[k]){
                    obj_[k] = false;
                }else if ((Object.entries(obj1[k]).length === 0 && obj1[k].constructor === Object) && (Object.entries(obj2[k]).length === 0 && obj2[k].constructor === Object)) {
                    obj_[k] = true;
                } else {
                    compare(obj1[k], obj2[k], obj_[k]);
                }
            } else {
                obj_[k] = (obj1[k] === obj2[k]);
            }

        }
    }

    if (Object.keys(obj1).length < Object.keys(obj2).length) { //check if both objects vary in length.
        var tmp = obj1;
        obj1 = obj2;
        obj2 = tmp;
    }

    compare(obj1, obj2, result);

    console.info(result);