phantomas/modules/requestsTo/requestsTo.js

Headless Chromium-based web performance metrics collector and monitoring tool

/**
 * Number of requests it took to make the page enter DomContentLoaded and DomComplete states accordingly
 */
"use strict";

module.exports = function (phantomas) {
  phantomas.setMetric("requestsToFirstPaint"); // @desc number of HTTP requests it took to make the first paint
  phantomas.setMetric("domainsToFirstPaint"); // @desc number of domains used to make the first paint @offenders
  phantomas.setMetric("requestsToDomContentLoaded"); // @desc number of HTTP requests it took to make the page reach DomContentLoaded state
  phantomas.setMetric("domainsToDomContentLoaded"); // @desc number of domains used to make the page reach DomContentLoaded state @offenders
  phantomas.setMetric("requestsToDomComplete"); // @desc number of HTTP requests it took to make the page reach DomComplete state
  phantomas.setMetric("domainsToDomComplete"); // @desc number of domains used to make the page reach DomComplete state @offenders

  var Collection = require("../../lib/collection"),
    domains = new Collection(),
    requests = 0;

  function setDomainMetric(metricName) {
    phantomas.setMetric(metricName, domains.getLength());
    domains.sort().forEach(function (domain, cnt) {
      phantomas.addOffender(metricName, { domain, requests: cnt });
    });
  }

  phantomas.on("recv", (entry) => {
    //phantomas.log('requestsTo: #%d <%s> / %s', requests, entry.url, entry.domain);

    requests++;

    if (entry.domain) {
      domains.push(entry.domain);
    }
  });

  phantomas.on("milestone", (name) => {
    switch (name) {
      case "firstPaint":
        phantomas.setMetric("requestsToFirstPaint", requests);
        setDomainMetric("domainsToFirstPaint");
        break;

      case "domInteractive":
        phantomas.setMetric("requestsToDomContentLoaded", requests);
        setDomainMetric("domainsToDomContentLoaded");
        break;

      case "domComplete":
        phantomas.setMetric("requestsToDomComplete", requests);
        setDomainMetric("domainsToDomComplete");
        break;
    }
  });
};