scraper.js

const cheerio = require('cheerio');
const puppeteer = require('puppeteer');
/**  disable-eslint */

function parseSchedule(id) {
  return new Promise(async (resolve, reject) => {
    const url = `https://classes.cornell.edu/shared/schedule/${id}`;

    const browser = await puppeteer.launch({ args: ['--no-sandbox', '--disable-setuid-sandbox'] })
    const page = await browser.newPage();
    await page.goto(url, { timeout: 70000 });
    const html = await page.evaluate(() => document.body.innerHTML);
    const $ = cheerio.load(html);

    // Initialize a map of classes on schedule indicating that it is a 
    // selected class
    const coursesMap = {};
    const scheduleClasses = $('.fc-content');
    // Loop through all classes on schedule
    for (let i = 0; i < scheduleClasses.length; i++) {
      const scheduleClass = scheduleClasses[i];
      const courseCode = $(scheduleClass).children('span').first().text().trim();

      if (!coursesMap[courseCode]) coursesMap[courseCode] = true;
    }

    // Initialize list for class objects
    let classList = []

    const expander = $(".expander.ng-binding");
    // Loops through all expanders
    for (let i = 0; i < expander.length; i++) {
      const courseHeader = expander[i];

      // Grab course codes
      courseCode = $(courseHeader.children[1]).text().trim();

      // If the course is in the map on the schedule
      if (coursesMap[courseCode]) {

        // Initialize the class object
        let classInfo = {}
        classInfo['course'] = courseCode;

        // Grab course name
        courseNameRaw = $(courseHeader).text().trim();
        courseName = courseNameRaw.split(' ').slice(2).join(" ");
        classInfo['name'] = courseName;

        // Grab section ids
        const coursePinnedSection = $(courseHeader.parent.parent).find('.ng-binding.classnbr-pinned').toArray();
        classInfo['section'] = coursePinnedSection.map(section => section.children[0].data.trim());

        // Grab days for specific sections
        const coursePinnedDays = $(courseHeader.parent.parent).find('.mtg-pat.classnbr-pinned').toArray();
        classInfo['days'] = coursePinnedDays.map(day => $(day.children[2]).text().trim());

        // Grab times for specific sections
        const coursePinnedTimes = $(courseHeader.parent.parent).find('.mtg-time.classnbr-pinned').toArray();
        classInfo['times'] = coursePinnedTimes.map(time => $(time.children[2]).text().trim());

        // Add to class list
        classList.push(classInfo);

      }
    }
    resolve(classList);
    await browser.close();
  })
}

module.exports = {
  parseSchedule
}