Use puppeteer with mocha --parallel while keeping just one browser instance

puppeteer_hooks.js

'use strict';
// Use puppeteer with mocha --parallel while keeping just one browser instance
// run with `mocha --require puppeteer_hooks.js`
// It uses puppetter's connect method to wire test suites to the browser
// See : https://github.com/puppeteer/puppeteer/blob/main/docs/api.md#puppeteerconnectoptions
//Access the browser in tests using `this.browser`
const fs = require('fs').promises;
const path = require('path');
const os = require('os');

const puppeteer = require('puppeteer');

const options = {
  args:["--no-sandbox"]
};

const FILE = path.join(os.tmpdir(), 'mocha_puppeteer_wsEndpoint');

//Global browser
exports.mochaGlobalSetup = async function(){
  this.browser = await puppeteer.launch();
  await fs.writeFile(FILE, this.browser.wsEndpoint());
}

exports.mochaGlobalTeardown = async function(){
  await this.browser.close();
  await fs.unlink(FILE);
}

exports.mochaHooks = {
  async beforeAll(){
    const wsEndpoint = await fs.readFile(FILE, {encoding:"utf8"});
    if (!wsEndpoint) {
      throw new Error('Puppeteer\'s wsEndpoint not found');
    }
    this.browser = await puppeteer.connect({browserWSEndpoint:wsEndpoint});
  }
}