Avatar photo

Blog by

Manvel Saroyan

Rewriting Chromium Browser Automation

| extension, tests, web components, rewrite

In 2012 I was working for a matchmaking company as a developer at the online marketing department, affiliate tracking pixels installation was part of my regular job, also I had to manually test each single of them going through 4-5 pages sign-up form with a bunch of validation fields. Sometimes that would occupy 40-50% of my time and was a quite frustrative task. That was the time when I decided to create CBA - a prototype extension that helped me optimizing the task to only take less than 3% of my time and generate automated reports.

It was quite similar to one of the first videos I have created mid 2012 for promoting CBA on a random matchmaking website:

Since then I was searching for various usecases and enjoying fighting bot circumventions. Basically I have managed to create a script that would go to social networks to congratulate my friends with their birthday, like various posts in groups, newsfeed, visit various profiles, send friend requests and many more.


As I have switched my job in 2013 and failed integrating CBA into my daily tasks, I have stopped actively maintaining the project. Unfortunately such projects require active maintenance, first was the Facebook liking functionality went down and instead of playing cat and mouse game with Facebook I have decided to remove the automation script, later the recording started to work unreliable as the web was evolving and I was at the time busy developing Adblock Plus, so I decided to ignore all that problems as the code at that point was barely maintainable and each small change were introducing a regression. As the result I have stopped maintaining the project in 2015.


After 5 years of break in 2020 I have finally managed to start rewriting the CBA and in 2021 I have managed to finally launch the complete rewritten version of the CBA which include current changes:

Automated tests

Considering the complexity of the project, regressions were hardly avoidable, opening the project for the community is also something that requires constant QA. Automations implementation took most of my time while rewriting the extension, but now I can do bug fixes without worrying that I may spend more time on fixing the regressions and Github CI will take care of the rest.

Open sourcing

Finally the CBA has been open sourced and all the source codes can be found at the browser-automation github organization, including components and website, the actual code for the extension can be found at /browser-automation/cba. The reason behind the generic organization name is that after the rewrite of the CBA it should be trivial to prepare builds for Firefox and Edge, also plans are to work on the desktop app and make it less platform dependent in the future, so it seems to be a good idea to start ahead.

Components and UI

The rewrite hasn't introduced many UI changes, but rather it introduced replacement of old Jquery libraries with much more lightweight and independent Web Components. It did require some effort to rewrite the components, but now they have all the basis for easier modifications and are separate modules, so it's simpler and safer to introduce changes on top and work on more appealing UI.

All the components currently live in a new repository and whoever wants can contribute and improve them without worrying that they can introduce regressions, as the new components are being tested automatically both by unit and end to end tests.

Alos we are currently working hard to introduce a new UI, to make it more modern, less bulky and provide a better user experience. Stay tuned...


One of the most important change is async/await support in code injection(cs-inject and bg-inject), previously users in order to wait for async script injection they had to use combination of sendBgInstruction = false; and sendInstruction(), here is how it used to look like before:

sendBgInstruction = false;
chrome.tabs.query({active: true}, (tabs) =>
  chrome.tabs.remove(tabs[0].id, () =>
    chrome.tabs.remove(tab.id, () =>

And now same thing can be achieved using:

const [tab] = await browser.tabs.query({active: true});
await browser.tabs.remove(tab.id);

Drupal to SSG

There were several drawbacks in running a website on a Drupal server, mostly it was maintenance effort and performance. Thanks to @naarrek, we were also able to migrate website which previously fall as a victim of #drupalgeddon, to much more secure and performant instance of CMintS, it definitely still have huge room to improve around SEO and finally making the website not look like so 2010(we are working on it), but yet metrics are much more promising in comparison to the previous "red" one.

https://chrome-automation.com homepage performance audit

Future of the CBA

I think CBA can have quite promising future regarding the user growth, considering that it has more than 43 000 weekly users and the project has already been downloaded more than 250 000 times, it does seem to help people automate their boring daily tasks and I hope to make the automation creation in future much more simple and accessible for everyone with the help of @Newman with whom we are working hard on new UI and UX of the product and @Alex who is helping us with the business advices and planing, as we hope to find a way to make CBA sustainable in a long run.

Surely we have quite a lot of challenges in front of us, one of the biggest and important challenge will be the changes in the platforms(i.e. Manifest v3 introduction) and ensuring that CBA can continue being supported on Chrome in future.

Another challenge which I'm going to take is the revolutionizing the recording of the automation, currently the recording of the actions isn't working reliable enough considering the complexity of the modern web, but I'm willing to take the challenge and working hard on automation solution that will require the user least understanding of the programming and web, in order to create automations.

Those are quite big challenges which we will be working hard to tackle, especially now that we can involve more contributors, have better basis and time.

The latest data and user feedback analysis provided quite a lot of hints about how we can make CBA attractive to more users, how to drive more traffic and understood how we can drastically improve user retention rate to get maximum out of current 100+ daily installs - will follow up on this separately. The biggest problem right now is the small development team and people dedicated to the project, so any contribution is welcome and if you would like helping us with the development of CBA please do not hesitate reaching out to me at saroyanm@gmail.com.

Get CBA here.