Export more than one variable in ES6?

That is not valid syntax. You can do

export { Post }

or even just

export var Post = Parse.Object.extend('Post')

or shorten the whole file to

export default Parse.Object.extend('TestObject')
export var Post = Parse.Object.extend('Post')

Your imports are also incorrect, you’ll want to do

import TestObject, { Post } from '../store'

This is if you really want a single default export and a separate named export. You can also just make two named exports and have no default if you want, e.g.

export var TestObject = Parse.Object.extend('TestObject');
export var Post = Parse.Object.extend('Post');

or

var TestObject = Parse.Object.extend('TestObject');
var Post = Parse.Object.extend('Post');
export { TestObject, Post };

and import with

import { TestObject, Post } from '../store'