On Rendering Diffs

What an interesting article. I did not assume I would read it until the end when I opened it, but the writing was super clear and easy to follow.

At the end, I admire the craft and patience to try to solve code diff rendering, and wish the folks at GitHub could put the same effort to improve their platform.

On a side note, I feel that we’re going to see more and more of this type of agentic usage, in well defined sub tasks, and the ability of a model to try many possibilities is a huge gift here.

For anyone else who's suffering, paste this in the console in devtools:

  document.getElementsByTagName('main')[0].style.margin = '0 auto';

I was hoping that this would talk more about the logic behind generating a diff, rather than the optimisations involved in rendering the text.

IMO (as someone who doesn't have to deal with the actual rendering) it would go a bit deeper into talking about deciding how to show what has changed. There's a lot of improvements that could be made there. e.g. "whitespace has changed here" so there's no real code changes involved.

Or "this big list of imports has changed, and code formatting has line-wrapped the list into different lines" - gitlab for example copes poorly with this. I'd love to just see a clean diff that highlights the additional import, and not just ten lines of changes caused by adding one line to a big list of imported symbols/functions.

I disagree with the theory that scrolling frame rate doesn't need to be smooth for scrolling to feel smooth.

On mobile it kinda does. Scrolling diffs on mobile just kinda feels crap.

I have been spoiled by years of engineer hours spent getting scrolling to be 60- or even 120Hz smooth to match my finger, and diffs just.. isn't.

I know this is frustrating to hear, and that this is technically compounded by mobile probably having the lowest device performance to be playing with too, but.. There you go.

It is SO NICE to see people working on making fast, nice-to-use tools. It's a lovely experience to use diffshub. Thank you for creating it, and than you for the great write-up! (I made it "that far" )

A bit of a technical deep dive into how we built CodeView, a review surface that can handle rendering diffs of immense size, all in a browser.

I don’t have much to say except I appreciate the ASCII art.

rendering massive diffs is cool but ultimately a gimmick. in what scenario are you actually reading a 500k line diff?

something i'd really want to see from forges is alternate diff techniques: like AST diffing.