ES Modules, or ECMAScript Modules
foo.js
1 2 3 4 5 6 7 8 9 10 11 12 class ArticleNode { constructor(node, paragraph) { this.node = node this.paragraph = paragraph } } export function createOneArticleNode(){ let articleNode0 = new ArticleNode('foo', 'bar') console.log('a n: ', articleNode0) } bar.js
1 2 3 4 5 6 7 8 9 // jest test import { createOneArticleNode } from '../content_module.js' test('test es module 0', () => { console.