在两个 Javascript 文件之间共享一个常量值

Question

总的来说，我是 JS 和 Node 的新手。我正在尝试使用 Puppeteer 来简单地获取

标签的文本值并将其保存为常量。然后，我尝试在我的 Mocha 测试所在的 'base' class (index.js) 中使用该值。出于某种原因，我正在挣扎。我正在使用异步。

我的文件结构是：

这是我的 Puppeteer 脚本：

//customerChoices.js
module.exports = async(page) => {

  const frame = page.frames().find(frame => frame.name() === 'iframe');

  const saveYourChoicesButton = await frame.$('body > div > div > div > form > footer > div > button.permissions-block__submit');
  await saveYourChoicesButton.click({});

  await page.waitForSelector('.page-title');
  const confirmationMessageText = await frame.$eval('.submission-response__copy > p', e => e.textContent);

return confirmationMessageText

};

这是我的 index.js 脚本，我在其中尝试导入常量 confirmationMessageText 并在测试中使用它：

const confMessage = require('./test/uiTests/customerChoices');
const expect = require('chai').expect;
const puppeteer = require('puppeteer');
const _ = require('lodash');
const chai = require('chai');

describe('Update customer choices', function() {

      it('test all customer choices', async function() {
        const url = _.get(url, `${env}`);
        await page.goto(url);

        await customerChoices(page);
        const cm = awaitCustomerChoices(page);
        expect(cm).to.equal('Thank you. Your choices have been updated.');
      expect(cm).to.equal('Thank you. Your choices have been updated.');
        console.log(confirmationMessageText);
      });

我不清楚为什么 confirmationMessageText 是“谢谢。您的选择已更新。”来自 Puppeteer 脚本，但 'undefined' 来自 index.js?

如果它有用，我的 package.json 看起来像：

"engines": {
  "node": ">=6"
},
"dependencies": {
  "chai": "^4.1.2",
  "lodash": "^4.17.10",
  "mocha": "^5.2.0",
  "moment": "^2.22.2",
  "newman": "^4.0.1",
  "puppeteer": "^1.6.2",
  "yargs": "^12.0.1",
  "express": "^4.16.4",
  "supertest": "^3.3.0"
},
"devDependencies": {
  "chai-as-promised": "^7.1.1",
  "express": "^4.16.4",
  "supertest": "^3.3.0"
}
}

Answer 1

module.exports 不应异步更改，特别是如果它应该在函数调用时更改。 CommonJS 模块被评估一次，confMessage 是 async(page) => {...} 函数。

该函数应该 return 结果：

module.exports = async(page) => {
  ...
  return confirmationMessageText;
};

并像这样使用：

const cm = await customerChoices(page);

在两个 Javascript 文件之间共享一个常量值

Sharing a Constant value between two Javascript files

javascript

mocha.js

node.js

async.js