I actually saw several comments with HTTP URL posted, and that was the only one I bothered to comment on. So I thought that this is something better suited for bots than human.

I hacked this together over yesterday and today: https://github.com/fishy/https-bot.

Basically it uses the Firebase API (https://github.com/HackerNews/API) to find comments with HTTP URLs in them, try the HTTPS version, compare the contents, post back a comment if the contents are more than 95% similar.

The "95% similar" part was actually the first part I wrote in the code. At first I tried a few existing go packages implementing diff/lcs, but most of them was quite slow and does a lot of allocations when I'm comparing two randomly generated 10KiB blobs, so I wrote my own (https://pkg.go.dev/github.com/fishy/https-bot/similarity), which is optimized for space (it does almost no allocations), and it's also faster because allocations are slow. (I know this is an unfair comparison that most of the existing implementations need to give you an output that can be used to reconstruct the two blobs back, so at least some of their allocations are required and unavoidable)

I also wrote a bug that it would find the same HTTP url in every run and post the same comment over and over again. My apologize to dang or whoever dealt with it (or maybe the system is good enough that it blocked those repetitive comments automatically).

In the end it successfully made 6 comments across ~4 hours (not including the repetitive ones). All of those comments are flagged (likely due to hn policy), https://news.ycombinator.com/item?id=26692588 is the only one that's still visible to other users at the time of writing, if you are curious.

I just killed it completely from the request of dang. Although it only lived for a few hours, it's still a fun exercise. Maybe I'll convert it into a reddit bot next? Who knows.