I Let Free Web Gemini Code My Terrarium, and Now the Worms are Having an Identity Crisis

I built a terrarium simulation using Pygame a while back:

Let's check whether Gemini can add entirely new features to this Python codebase without blowing everything up.

Let's open up the project in VS Code:

I am using ReptClip for VS Code (an extension I built) to build the context and apply the diffs.

Let's addREADME.md, requirements.txt, and all Python files into the context (I know it's not ideal, but let's try):

Already 64,000 tokens. Let's paste it in:

What? The browser chat UI silently truncated the context I pasted in, without showing a single warning!

Luckily, the limit is larger if you upload the context as a file:

Let's type the prompt and hit send!

A 108-line diff. Now, I can copy the diffs and click Apply Diffs in my extension. It will automatically read them from the clipboard and apply the changes:

Let's try once more:

Even though ReptClip supports fuzzy matching in SEARCH blocks, the AI hallucinated too much, so the extension wasn't able to find a match.

Here is my new plan:

1. Give the AI only the project structure, README, and requirements.txt
2. Ask it which files it needs to see to implement the feature

It gave a list of the files it wants to see:

Since we already added the project structure and output format, let's uncheck them and add the files Gemini asked for:

Luckily, this time it didn't get truncated:

The new diff was 165 lines:

Let's apply the diffs:

Only one fuzzy match. Let's launch the terrarium:

There we go! We got the feature we asked for.

Time to make it harder. The new feature:

A suspiciously tiny diff that literally fits into a single screenshot:

I applied it anyway:

And ran the simulation:

The worms looked a bit different, but it was definitely far from what I asked. Let's try again with Gemini Pro.

It's using some big words:

It gave me a 265-line diff modifying 2 files. Let's see what it did.

I can't even see the worms.

I thought maybe they were still growing. I waited in front of the simulation at 8x speed for days*:

Still empty. Let's try with Gemini Extended Thinking:

According to Gemini, it found the exact bug:

I applied its recommended patch:

Still no worms.

Let me handle this alone without taking a screenshot every 5 seconds. I'll come back soon.

🏃 ...

So, according to Gemini, this was the reason:

Anyway, I gave it ant.py so it could refer to it and generate proper diffs. This time, I was able to see something!

Now THAT is what actual peristalsis looks like!

I think that's enough for now without breaking it even more.