TehPers

open to any feedback, always willing to learn

A common pattern with executable Python scripts is to:

• Add a shebang at the top (#!/usr/bin/env python3) to make it easier to execute
• Check if __name__ == "__main__" before running any of the script so the functions can be imported into another script without running all the code at the bottom

The never type comes more from type theory and isn’t common in other languages (though TS has never). Similar to 0 or the null set, it exists as a “base case” for types. For example, where you have unions of T1 | T2 | ..., the “empty union” is the never type. Similarly, for set theory, a union of no sets is the null set, and in algebra, the summation of no numbers is 0.

In practice, because it can’t be constructed, it can be used in unique ways. These properties happen to be super useful in niche places.

Because if it never returns, then it has no return value.

Then how would you annotate having no return value?

I don’t know where None comes from (what’s the T in Option<T>?)

Assuming you meant (), that’s a unit type with one valid value. It’s a ZST, but can be created and returned.

! is a bottom type. It’s uninhabited. Can’t be created. Functions can never return it because they can never construct it. So why’s this useful? It can be coerced to any type.

Because the set of valid values for ! is the null set, by contradiction, there do not exist any values valid for the type ! that are invalid for any other type T. Therefore, all valid values of ! are also valid values of any other type T, and you can always convert from it to any other type.

Notably, this is already possible, but language support for it isn’t amazing:

enum A {}

fn bar(a: A) {
    let foo: Box<Arc<Rc<Mutex<String>>>> = match a {}
}

Heck you can even do this today:

// `loop {}` never returns, so its type is `!`:
let blah: String = loop {};

Any website using CSR only can’t have a RCE because the code runs on the client. Any code capable of RSC that runs server and client side may be vulnerable.

From what I’ve seen, the exploit is a special request from a client that functionally lets you exec anything you want (via Function’s constructor). If your server is unpatched and recognizes the request, it may be (likely is) vulnerable.

I’m sure we’ll get more details over time and tools to manually check if a site is compromised.

30 is assuming you write code for all 30 days. In practice, it’s closer to 20, so 75 tests per day. It’s doable on some days for sure (if we include parameterized tests), but I don’t strictly write code everyday either.

Still, I agree with them that you generally want to write a lot of tests, but volume is less important than quality and thoroughness. The author using the volume alone as a meaningful metric is nonsense.

This is more likely the actual incident report:

A change made to how Cloudflare’s Web Application Firewall parses requests caused Cloudflare’s network to be unavailable for several minutes this morning. This was not an attack; the change was deployed by our team to help mitigate the industry-wide vulnerability disclosed this week in React Server Components. We will share more information as we have it today.

Edit: If you like reading

1500 tests is a lot. That doesn’t mean anything if the tests aren’t testing the right thing.

My experience was that it generates tests for the sake of generating them. Some are good. Many are useless. Without a good understanding of what it’s generating, you have no way of knowing which are good and which are useless.

It ended up being faster for me to just learn the testing libraries and write my own tests. That way I was sure every test served a purpose and tested the right thing.

I am interested to see if these tools can be used to tackle tech debt, as often the argument for not addressing tech debt is a lack of time, or if they would just contribute it to it, even with thorough instructions and guardrails.

From my experience working with people who use them heavily, they introduce new ways of accumulating tech debt. Those projects usually end up having essays of feature spec docs, prompts, state files (all in prose of course), etc. Those files are anywhere from hundreds to thousands of lines long, and there’s a lot of them. There’s no way anybody is spending hours reading through enough markdown to fill twenty encyclopedia-sized books just to make sure it’s all up-to-date. At least, I can promise that I won’t be doing it, nor will anyone I know (including those using AI this way).

And it often generates a bunch of markdown docs which are plain drivel, luckily most devs just delete those before I see them.

My favorite is when it generates a tree of the files in a directory in a README and a description for each file. How the fuck is this useful? Files will be added and removed, so there’s now an additional task to update these docs whenever that happens. Nobody will remember to do so because no tool is going to enforce that and it’s stupid anyway.

Sure, document high level directories. But do you really need that all in the top level README?

But for real if anyone in management is listening, take it from an old asshole who has done this job since the 80s: AI fucking sucks!

Nothing to add. Just quoting this section because it needs to be highlighted lol.

Why not?

Are you asking the author or people in general? If the author didn’t answer “why not” for you, then I can.

Yes, I’ve used Claude. Let’s skip that part.

If you don’t know how to write or identify defensive code, you can’t know if the LLM generated defensive code. So in order for a LLM to be trusted to generate defensive code, it needs to do so 100% of the time, or very close to that.

You seem to be under the impression that Claude does so, but you presumably can tell if code is written with sufficient guards and tests. You know to ask the LLM to evaluate and revise the code. Someone without experience will not know to ask that.

Speaking now from my experience, after using Claude for work to write tests, I came out of that project with no additional experience writing tests. I had to do another personal project after that to learn the testing library we used. Had that work project given me sufficient time to actually do the work, I’d have spent some time learning the testing library we used. That was unfortunately not the case.

The tests Claude generated were too rigid. It didn’t test important functionality of the software. It tested exact inputs/outputs using localized output values, meaning changing localizations was potentially enough to break tests. It tested cases that didn’t need to be tested, like whether certain dependency calls were done in a specific order (those calls were done in parallel anyway). It wrote some good tests, but a lot of additional tests that weren’t needed, and skipped some tests that were needed.

As a tool to help someone who already knows what they’re doing, it can be useful. It’s not a good tool for people who don’t know what they’re doing.

Homepage:

A language compiled to Bash.

Also:

A modern, type-safe programming language that catches bugs and errors at compile time.

Mixins are composition! They don’t describe what a type is (“circle” is a “shape”, etc) but rather what they can do (“circle” can have its area calculated, it can be drawn, it can be serialized, etc). Mixins in Python just so happen to be implemented by adding base classes.

Inheritance itself isn’t really a problem. It usually only matters when you have unnecessarily deep hierarchies, where a change in a base class can change functionality in dozens of classes in an unintentional way. Similarly, it can add complexity once the hierarchy is deep enough, but only really if you throw too much into the base classes.

Python’s ABCs are more of interfaces though, which is why despite Python using base classes to “inherit” them, a lot of that is really composition (or putting a class together from parts) rather than inheriting and overriding implementation details from a parent/grandparent/etc type.

OOP debates usually turn into inheritance vs composition which is weird because every modern used language has objects and most OOP languages lean towards composition these days.

The core OOP concepts are universal and important.

What might benefit you here is a proper GC. There are a few libraries to do this in Rust, though I don’t have any good recommendations since I haven’t needed this myself yet.

I miss the days when it was simpler as well. Back before there were botnets with hundreds of thousands of compromised routers across several countries that could send tens of terabytes per second of data to your server for a sustained period of time. Back before there were thousands of bots crawling every IP and domain imaginable for exposed, abusable ports and wp-admin endpoints. Back before people started to compete in how many 9s of uptime they supported (before killing that all with LLMs anyway).

Sadly, we can’t go back to those times. Doing so with a production service would not end well.

The issue is not npm. Npm is a solution to a problem, even if it isn’t perfect.

The issue is we live in a different landscape.

Eclipse was great, having used it in the past, but its features are not exclusive to Eclipse. I can do the same inlining and extracting of code in vscode with code actions. The compile times weren’t seconds for me in the past, but they are for me now. Vite helps that even more (though that’s comparing JS to Java).

I agree in general with the list, but there is some stuff I disagree with still. For example, the very first section: “Work on more than one thing”.

Like a CPU thread, if you’re responsible for multiple streams of work, you can deal with one stream getting blocked by rolling onto another one.

This is written from the perspective of the developer, not the stakeholders. Compared to a CPU, you are a single thread. You cannot work on two things at the same time. What this is referring to is not parallelism, but a form of concurrency. Like a CPU thread, when two tasks are being executed concurrently, one task is always blocked. This means that while you, the developer, are always working, you also are always blocking at least one task, meaning you are also always blocked on at least one task.

Instead of working on two tasks at once, pick up the second task only when the first becomes blocked.

I believe this might be what the author was trying to convey, but the title, some wording in the section, and the bullet point at the end (“Working on at least two things at a time, so when one gets blocked you can switch to the other”) contradict that and give the impression that you should always be working on two or more things at a time.

use as normal a developer stack as possible.

This, I mostly agree with, but I disagree with the wording. You should be using the same tools as the rest of your team when the tool matters. However, using different Git interfaces shouldn’t matter. I’d argue the same holds true for editors as long as the editors all have the features needed for the project.

For application work, some variety in dev environments can help you find bugs sooner even. Using different environments for development lets you test different environments naturally. For services, this is less relevant.

This is a super interesting approach to JS. Conceptually, it’s really cool. In practice, I don’t think I’d do it (at least for any projects I can think of) because explaining it to others would be difficult and representing complex logic as “commands” sounds a bit difficult.

In a weird way, it reminds me of actor frameworks though. The difference is of course the separation of effects.

One thing I wish the author would have done, though, is add some type hints. I know it’s about JS, but even some jsdoc types would have helped. It was a bit hard to know at first what the input types were to these functions.

Saw Diesel mentioned, but also wanted to throw SeaORM out there. Might be worth looking into as well.

No, the attribute is unsafe. An unsafe function is marked unsafe fn.

Also, unsafe by itself just means there are invariants that must me manually upheld to avoid unsound behavior. If those invariants are upheld, then it doesn’t matter if it’s unsafe.