Sharing a Constant value between two Javascript files

Question

I'm new to JS and Node in general. I'm trying to use Puppeteer to simply get the text value of a

tag and save it to a constant. I'm then trying to use the value in a 'base' class (index.js) where my Mocha tests live. For some reason, I'm struggling. I'm using async.

My file structure is:

Here is my Puppeteer script:

 //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 }; 

Here is my index.js script where I try to import the constant confirmationMessageText and use it in a test:

 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); }); 

I'm unclear why confirmationMessageText is "Thank you. Your choices have been updated.' from the Puppeteer script but 'undefined' from within index.js?

In case it's useful, my package.json looks like:

 "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 shouldn't be changed asynchronously, especially if it's supposed to be changed on function call. CommonJS modules are evaluated once, confMessage is async(page) => {...} function.

The function should just return the result:

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

And used like:

const cm = await customerChoices(page);