Hacker News Lookup: A Chrome extension built with Clojurescript


Hacker News is a social news website focusing on computer science and entrepreneurship, and has become the front page of the web for many people (me included). “I have not found a public internet forum with better technical commentary” and I would usually prefer reading comments on HN rather than on the original website. I would often find myself searching for the HN thread on the pages I visit, or when someone sent me a link to an article or resource and because this was happening so often, I had to do something about it; I had to ease this painful process that takes more than 3 clicks.


Screenshot of Hacker News Lookup extension

Hacker News Lookup is a minimal and non-intrusive Chrome extension that allows you to lookup on Hacker News the page that you are currently viewing, and browse for the related topics. It is simple, fast and beautiful :-)

It only runs when you click on the extension button and queries the algolia api. It does not track any of your browsing history.

The extension is available on the Chrome store here and the source code here: https://github.com/jazzytomato/hnlookup


The extension is doing the bare minimum; however, I believe there could be more to it than just showing hits on Hacker News. I would like to allow people to browse the web as part of a community (adding adapters for other sources, like Reddit), but I am not sure yet if I will structure the codebase in that direction or if that will be part of another project.

Building a chrome extension with ClojureScript

I had already developed a Chrome extension in the past, but the development process was cumbersome.

Luckily, I was in the course of learning Clojure (with this awesome book), and watching some random Clojure tech talks when I heard about figwheel. As I learned more about ClojureScript, I realised that it was a game changer. I do a lot of back-end programming at work, and I am having a hard time keeping up with the pace at which the Javascript ecosystem evolves. What a relief when you realise that you don’t have toThere is no better way of developing front-end application than with ClojureScript.

Below is a 20 seconds video example of what the development workflow looks like (look at the extension on the right as I change and evaluate the code)

Here is what happens in the video:

  • Evaluation of the code directly in the editor (the selected code is sent in the live REPL at the bottom of the editor)
  • The code evaluated is connected to the chrome extension, and changes the current state of the app
  • Modifications to the loading component are hot reloaded
  • Errors and warnings are intercepted and sent to the page