Integration test failure using Puppeteer - node.js

Question

I am new to Node.JS and very curious to learn more about it, therefore I decided to do some exercises from a book.
The point which I am struggling is with the integration test.
I would like to have a crawler checking my application to see if the links are working fine. For that I am using the following code:
package.json
{
"main": "meadowlark.js",
"scripts": {
"test": "jest",
"lint": "eslint meadowlark.js lib"
},
"dependencies": {
"express": "^4.17.1",
"express3-handlebars": "^0.5.2"
},
"devDependencies": {
"eslint": "^5.15.3",
"jest": "^24.9.0",
"portfinder": "^1.0.20",
"puppeteer": "^1.13.0"
}
}
integration-tests/basic-navigation.test.js
const portfinder = require('portfinder')
const puppeteer = require('puppeteer')
const app = require('../meadowlark.js')
let server = null
let port = null
beforeEach(async () => {
port = await portfinder.getPortPromise()
server = app.listen(port)
})
afterEach(() => {
server.close()
})
test('home page links to about page', async () => {
const browser = await puppeteer.launch()
const page = await browser.newPage()
await page.goto(`http://localhost:${port}`)
await Promise.all([
page.waitForNavigation(),
page.click('[data-test-id="about"]'),
])
expect(page.url()).toBe(`http://localhost:${port}/about`)
await browser.close()
})
meadowlark.js
// Starting an express application
var express = require('express');
var app = express();
/* eslint-disable no-undef */
const port = process.env.PORT || 3000
/* eslint-enable no-undef */
// Set up handlebars view engine (Templating)
// Check the views folder for html skeleton and the respective
// handlebars
var handlebars = require('express3-handlebars')
.create({ defaultLayout:'main' });
app.engine('handlebars', handlebars.engine);
app.set('view engine', 'handlebars');
/* eslint-disable no-undef */
app.set('port', process.env.PORT || 3000);
/* eslint-enable no-undef */
const handlers = require('./lib/handlers')
// Function to generate the quote of the day
//const fortune = require('./lib/fortune')
// Homepage
app.get('/', handlers.home)
// About
app.get('/about', handlers.about);
// 404
app.use(handlers.notFound);
// 500
app.use(handlers.serverError)
// Binding to the port
if(require.main === module) {
app.listen(port, () => {
console.log( `Express started on http://localhost:${port}` +
'; press Ctrl-C to terminate.' )
})
} else {
module.exports = app
}
Error
meadowlark/integration-tests/basic-navigation.test.js:9
beforeEach(async () => {
^
ReferenceError: beforeEach is not defined
What am I missing/ doing wrong here?

Answer 1

You need to run your test through jest and not plain node otherwise all the globals defined by jest won't exist.
Example if you're using yarn:
yarn jest to run all tests it can find based on jest default settings (see documentation to customize)
yarn jest meadowlark/integration-tests/basic-navigation.test.js to only run your file