phantomas/extensions/pageSource/pageSource.js

Headless Chromium-based web performance metrics collector and monitoring tool

/**
 * Saves the source of page being loaded to a file
 *
 * Please note that saving each file takes a few ms.
 * Consider increasing default timeout.
 *
 * Run phantomas with --page-source option to use this module.
 */
"use strict";

module.exports = (phantomas) => {
  if (!phantomas.getParam("page-source")) {
    phantomas.log(
      "To enable page-source of page being loaded run phantomas with --page-source option"
    );
    return;
  }

  const fs = require("fs"),
    format = require("util").format,
    workingDirectory = require("process").cwd(),
    // grab output dir from argument, defaults to working directory
    pageSourceOutputDir = phantomas
      .getParam("page-source-dir", workingDirectory)
      .replace(/\/+$/, ""),
    path = format("%s/phantomas_%d.html", pageSourceOutputDir, Date.now());

  phantomas.log("Will store page source in %s", path);

  // https://github.com/GoogleChrome/puppeteer/blob/v1.11.0/docs/api.md#pageevaluatepagefunction-args
  phantomas.on("beforeClose", (page) => {
    // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise
    return new Promise(async (resolve) => {
      // https://github.com/GoogleChrome/puppeteer/blob/v1.11.0/docs/api.md#pageevaluatepagefunction-args
      const bodyHandle = await page.$("body");

      /* istanbul ignore next */
      const html = await page.evaluate((body) => body.innerHTML, bodyHandle);

      // phantomas.log(html);
      fs.writeFileSync(path, html);

      phantomas.log("Page source stored in %s", path);

      // let clients know that we stored the page source in a file
      phantomas.emit("pageSource", path);
      resolve();
    });
  });
};