Multi-client remote debugging using ChromeDriver and Chrome DevTools protocol

Question

So with Chrome 63 there is now support for Multi-client remote debugging (https://developers.google.com/web/updates/2017/10/devtools-release-notes)

What I want to achieve is use the Chrome DevTools Protocol HeapProfiler with some selenium tests. I'm running version 64 Chrome dev channel and ChromeDriver 2.33.

ChromeOptions options = newChromeOptions();
options.addArguments("--remote-debugging-port=9222");
WebDriver driver = new ChromeDriver(options);
... selenium stuff

A new chrome window will open and hang until it times out. I can confirm that the chrome window opened is chrome 64 by going to help > about google chrome to check the version. I get this error which appears to be the the webdriver losing connection.

Exception in thread "main" org.openqa.selenium.WebDriverException: chrome not 
reachable

The DevTools Protocol is working because I am able to open http://localhost:9222 in another chrome window and see debugging interface.

Has anyone been able to get these two things to work together?

Thanks :)

Answer 1

Here the catch was that if you pass the "remote-debugging-port" switch then chromedriver has a bug where it still internally assigns a randon port and keep trying to connect to it rather than connecting to 9222 port.

options.addArguments("--remote-debugging-port=9222");

We can solve this by skipping this command switch and let chrome decides this random port and extract this port number from chromedriver logs.

I made it work and here I have blogged it in detail.

https://medium.com/@sahajamit/selenium-chrome-dev-tools-makes-a-perfect-browser-automation-recipe-c35c7f6a2360

Answer 2

Selenium 4 release will have a user friendly API for Chrome DevTools protocol. I just finished implementing Network and Performance domains for the Selenium Java client. https://github.com/SeleniumHQ/selenium/pull/7212

In addition, there is a generic API for all domains in Java client that was merged a while ago. All those new features will be released probably in the next Alpha release.

This is a nice article on how to use Log: https://codoid.com/selenium-4-chrome-devtools-log-entry-listeners/