Get google ranking for given keywords

google-ranking.js

const scavenger = require('scavenger');

module.exports = googleRanking;

/**
* @async
* @param  {String} keywords
* @param  {String} compareUrl
* @param  {Number} pagesAmount
* @return {Number}
**/
function googleRanking(keywords, compareUrl, pagesAmount) {
    pagesAmount = pagesAmount || 2;
    
    const urls = scavenger.paginateUrl({
        baseUrl: 'https://www.google.com/search?',
        params: {
            q: keywords,
            start: 0
        },
        paginationParam: 'start',
        limit: Math.round(pagesAmount) * 10,
        step: 10
    });

    const extract = scavenger.createExtractor({
        scope: 'div.rc',
        fields: {
            title: 'h3.r a',
            url: {
                selector: 'h3.r a',
                attribute: 'href'
            },
        }
    });

    return scavenger.scrape(urls, { waitMs: 5000 }, extract)
    .then((pages) => {
        const results = [].concat.apply([], pages);
        const ranking = _.findIndex(results, (res) => {
            return res.url === compareUrl;
        });
        
        return ranking === -1 ? ranking : ranking + 1;
    });
}