penthouse/lib/browser.js

Generate critical path CSS for web pages

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.addJob = addJob;
exports.removeJob = removeJob;
exports.launchBrowserIfNeeded = launchBrowserIfNeeded;
exports.closeBrowser = closeBrowser;
exports.restartBrowser = restartBrowser;
exports.browserIsRunning = browserIsRunning;
exports.getOpenBrowserPage = getOpenBrowserPage;
exports.closeBrowserPage = closeBrowserPage;

var _puppeteer = _interopRequireDefault(require("puppeteer"));

var _debug = _interopRequireDefault(require("debug"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

const debuglog = (0, _debug.default)('penthouse:browser'); // shared between penthouse calls

let browser = null;
let _browserLaunchPromise = null;
const reusableBrowserPages = []; // keep track of when we can close the browser penthouse uses;
// kept open by continuous use

let ongoingJobs = 0;

function addJob() {
  ongoingJobs = ongoingJobs + 1;
}

function removeJob() {
  ongoingJobs = ongoingJobs - 1;
}

const DEFAULT_PUPPETEER_LAUNCH_ARGS = ['--disable-setuid-sandbox', '--no-sandbox', '--ignore-certificate-errors' // better for Docker:
// https://github.com/GoogleChrome/puppeteer/blob/master/docs/troubleshooting.md#tips
// (however caused memory leaks in Penthouse when testing in Ubuntu, hence disabled)
// '--disable-dev-shm-usage'
];

async function launchBrowserIfNeeded({
  getBrowser,
  width,
  height
}) {
  const usingCustomGetBrowser = getBrowser && typeof getBrowser === 'function';

  if (usingCustomGetBrowser && !_browserLaunchPromise) {
    debuglog('using browser provided via getBrowser option');
    _browserLaunchPromise = Promise.resolve(getBrowser());
  }

  if (!_browserLaunchPromise) {
    if (browser) {
      // we have already a running browser
      return;
    }

    debuglog('no browser instance, launching new browser..');
    _browserLaunchPromise = _puppeteer.default.launch({
      args: DEFAULT_PUPPETEER_LAUNCH_ARGS,
      ignoreHTTPSErrors: true,
      defaultViewport: {
        width,
        height
      }
    });
  }

  _browserLaunchPromise.then(async browser => {
    debuglog('browser ready');
    const browserPages = await browser.pages();

    if (browserPages.length > 0) {
      debuglog('re-using the page browser launched with');
      browserPages.forEach(Page => {
        if (!reusableBrowserPages.includes(Page)) {
          Page.notSetupForPenthouse = true;
          reusableBrowserPages.push(Page);
        } else {
          debuglog('ignoring browser page already inside reusableBrowserPages');
        }
      });
    }

    return browser;
  });

  browser = await _browserLaunchPromise;
  _browserLaunchPromise = null;
}

async function closeBrowser({
  forceClose,
  unstableKeepBrowserAlive
}) {
  if (browser && (forceClose || !unstableKeepBrowserAlive)) {
    if (ongoingJobs > 0) {
      debuglog('keeping browser open as ongoingJobs: ' + ongoingJobs);
    } else if (browser && browser.close) {
      browser.close();
      browser = null;
      _browserLaunchPromise = null;
      debuglog('closed browser');
    }
  }
}

async function restartBrowser({
  getBrowser,
  width,
  height
}) {
  let browserPages;

  if (browser) {
    browserPages = await browser.pages();
  }

  debuglog('restartBrowser called' + browser && browserPages && '\n_browserPagesOpen: ' + browserPages.length); // for some reason Chromium is no longer opened;
  // perhaps it crashed

  if (_browserLaunchPromise) {
    // in this case the browser is already restarting
    await _browserLaunchPromise; // if getBrowser is specified the user is managing the puppeteer browser themselves,
    // so we do nothing.
  } else if (!getBrowser) {
    console.log('now restarting chrome after crash');
    browser = null;
    await launchBrowserIfNeeded({
      width,
      height
    });
  }
}

async function browserIsRunning() {
  try {
    // will throw 'Not opened' error if browser is not running
    await browser.version();
    return true;
  } catch (e) {
    return false;
  }
}

async function getOpenBrowserPage() {
  const browserPages = await browser.pages(); // if any re-usable pages to use, avoid unnecessary page open/close calls

  if (reusableBrowserPages.length > 0) {
    debuglog('re-using browser page for generateCriticalCss, remaining at: ' + browserPages.length);
    const reusedPage = reusableBrowserPages.pop();
    let reused = true; // if we haven't yet run any penthouse jobs with this page,
    // don't consider it reused - i.e. it will need to be configured.

    if (reusedPage.notSetupForPenthouse) {
      reused = false; // but only once

      delete reusedPage.notSetupForPenthouse;
    }

    return Promise.resolve({
      page: reusedPage,
      reused
    });
  }

  debuglog('adding browser page for generateCriticalCss, before adding was: ' + browserPages.length);
  return browser.newPage().then(page => {
    return {
      page
    };
  });
}

async function closeBrowserPage({
  page,
  error,
  unstableKeepBrowserAlive,
  unstableKeepOpenPages
}) {
  if (!browser || !page) {
    return;
  }

  const browserPages = await browser.pages();
  debuglog('remove (maybe) browser page for generateCriticalCss, before removing was: ' + browserPages.length);
  const badErrors = ['Target closed', 'Page crashed'];

  if (page && !(error && badErrors.some(badError => error.toString().indexOf(badError) > -1))) {
    // Without try/catch if error penthouse will crash if error here,
    // and wont restart properly
    try {
      // must await here, otherwise will receive errors if closing
      // browser before page is properly closed,
      // however in unstableKeepBrowserAlive browser is never closed by penthouse.
      if (unstableKeepBrowserAlive) {
        if (unstableKeepOpenPages !== 'all' && browserPages.length > unstableKeepOpenPages) {
          page.close();
        } else {
          debuglog('saving page for re-use, instead of closing');

          if (error) {
            // When a penthouse job execution errors,
            // in some conditions when later re-use the page
            // certain methods don't work,
            // such as Page.setUserAgent never resolving.
            // "resetting" the page by navigation to about:blank first fixes this.
            debuglog('Reset page first..');
            await page.goto('about:blank').then(() => {
              debuglog('... page reset DONE');
            });
          }

          reusableBrowserPages.push(page);
        }
      } else {
        debuglog('now try to close browser page');
        await page.close();
      }
    } catch (err) {
      debuglog('failed to close browser page (ignoring)');
    }
  }
}