diff.js

// https://babeljs.io/repl/#?evaluate=true

function getDiff(that, other) {
    if (that == other) { return {} }

    if (_.isEmpty(other)) {
        return {all: true}
    }
    
    if (_.isObject(that)) {
      if (!_.isObject(other)) { return {all: true} }
      
      const keysDiff = _.difference(_.keys(that), _.keys(other))
      const keysDiffResult = _(keysDiff).map(k => [k, {all: true}]).zipObject().value()
      
      const innerDiff = _(that)
          .keys()
          .map(k => [k, getDiff(that[k], other[k])])
          .reject(([k, v]) => _.isEmpty(v))
          .zipObject()
          .value()
      
      if (_.isEmpty(innerDiff) && _.isEmpty(keysDiffResult)) {
        return {}
      }
      
      return {values: _.assign(innerDiff, keysDiffResult)}
    }

    return {all: true}
}

console.log(_([
  [{a: 1}, null,                                  {all: true}],
  [{a: 1}, {},                                    {all: true}],
  [{a: 1}, {a: 1},                                {}],
  [{a: 1}, {a: 2},                                {"values": {"a": {"all": true}}}],
  [{a: 1}, {b: 2},                                {values: {a: {all: true}}}],
  [{a: 1}, {a: {c: 2}},                           {values: {a: {all: true}}}],
  [{a: {c: 2}}, {a: {c: 2}},                      {}],
  [{a: {b: 2, d: 4}}, {a: {c: 2}},                {values: {a: {values: {b: {all: true}, d: {all: true}}}}}  ],
  [{a: {b: {d: 4}}}, {a: {b: {}}},                {"values":{"a":{"values":{"b":{"all":true}}}}} ],
  [{a: {c: 2}}, {a: {b: 2, d: 4}},                {values: {a: {values: {c: {all: true}}}}}],
]).map(([a, b, res]) => _.isEqual(getDiff(a, b), res)
    ? 'ok'
    : `getDiff(${JSON.stringify(a)}, ${JSON.stringify(b)}) != ${JSON.stringify(res)} || ${JSON.stringify(getDiff(a, b))}`).value().join('\n'),
    '\n\n\n\n')