`satisfies` is my favorite TypeScript keyword (2024)
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Re: `satisfies` is my favorite TypeScript keyword (2024)
#2> This keyword is a bit esoteric and not very common, but it comes in handy in some scenarios where you’d otherwise pull your hair out.
Typescript in a nutshell. That said, satisfies is a good keyword!
Re: `satisfies` is my favorite TypeScript keyword (2024)
#3> TypeScript is a wonderfully advanced language though it has an unfortunately steep learning curve
An extremely steep one.
The average multi-year TypeScript developer I meet can barely write a basic utility type, let alone has any general (non TypeScript related) notion of cardinality or sub typing. Hell, ask someone to write a signature for array flat, you'd be surprised how many would fail.
Too many really stop at the very basics.
And even though I consider myself okay at TypeScript, the gap with the more skilled of my colleagues is still impressively huge.
I think there's a dual problem, on one side type-level programming isn't taken seriously by the average dev, and is generally not nurtured.
On the other hand, the amount of ideas, theory, and even worse implementation details of the TypeScript compiler are far from negligible.
Oh, and it really doesn't help that TypeScript is insanely verbose, this can easily balloon when your signatures have multiple type dependencies (think composing functions that can have different outputs and different failures).
Re: `satisfies` is my favorite TypeScript keyword (2024)
#4> TypeScript is a wonderfully advanced language though it has an unfortunately steep learning curve An extremely steep one. The average multi-year TypeScript developer I meet can barely write a basic utility type, let alone has any general (non TypeScript related) notion of cardinality or sub typing. Hell, ask someone to write a signature for array flat, you'd be surprised how many would fail. Too many really stop at…
these are things most developers don't know how to do in most language's type systems. I think only rust with its focus on functional roots has seen similar focus on utilizing its type system to its fullest extent.
Re: `satisfies` is my favorite TypeScript keyword (2024)
#5the cool thing about Typescript is that you never have to know any of this to deliver highly performant enterprise scale software
Re: `satisfies` is my favorite TypeScript keyword (2024)
#6This is wordier than just "as const", what advantage does it give? (I am a newbie and genuinely don't know)
edit: perhaps the advantage only comes into play for mutable values, where you want a narrower type than default, but not that narrow. Indeed, this is covered in the article, but CTRL+F "as const" doesn't work on the page for whatever reason, so I missed it.
Re: `satisfies` is my favorite TypeScript keyword (2024)
#7> TypeScript is a wonderfully advanced language though it has an unfortunately steep learning curve An extremely steep one. The average multi-year TypeScript developer I meet can barely write a basic utility type, let alone has any general (non TypeScript related) notion of cardinality or sub typing. Hell, ask someone to write a signature for array flat, you'd be surprised how many would fail. Too many really stop at…
TypeScript codebases I've seen generally seem to have the widest demonstration of skill gap versus other languages I use.
For example, I don't ever see anyone using `dynamic` or `object` in C#, but I will often see less skilled developers using `any` and `// @ts-ignore` in TypeScript at every possible opportunity even if it's making their development experience categorically worse.
For these developers, the `type` keyword is totally unknown. They don't know how to make a type, or what `Omit` is, or how to extend a type. Hell, they usually don't even know what a union is. Or generics.
I sometimes think that in trying to just be a superset of JavaScript, and it being constantly advertised as so, TypeScript does not/did not get taken seriously enough as a standalone language because it's far too simple to just slot sloppy JavaScript into TypeScript. TypeScript seems a lot better now of having a more sane tsconfig.json, but it still isn't strict enough by default.
This is a strong contrast with other languages that compile to JavaScript, like https://rescript-lang.org/ which has an example of pattern matching right there on the home page.
Which brings me onto another aspect I don't really like about TypeScript; it's constantly own-goaling itself because of it's "we don't add anything except syntax and types" philosophy. I don't think TypeScript will ever get pattern matching as a result, which is absurd, because it has unions.
Re: `satisfies` is my favorite TypeScript keyword (2024)
#8I’m so frustrated by satisfies because it eliminates optional properties.
I want an object of ‘LayerConfig’ elements where each key is the name of a possible layer. Without ‘satisfies’ I have to name every layer twice in my config. But with it, I can’t have optional properties (eg. Half the layers are fine with the default values for some properties).
The best I’ve found is a hack that uses a function. But this whole thing where my key literals widen into “string” is a constant annoyance to otherwise very elegant code.
Re: `satisfies` is my favorite TypeScript keyword (2024)
#9The second example confuses me. The Person type has isCool: boolean, not an explicit true. How does using satisfies here pass coolPeopleOnly?
Re: `satisfies` is my favorite TypeScript keyword (2024)
#10> TypeScript is a wonderfully advanced language though it has an unfortunately steep learning curve An extremely steep one. The average multi-year TypeScript developer I meet can barely write a basic utility type, let alone has any general (non TypeScript related) notion of cardinality or sub typing. Hell, ask someone to write a signature for array flat, you'd be surprised how many would fail. Too many really stop at…
Honestly I just use TypeScript to prevent `1 + [] == "1"` and check that functions are called with arguments. I don't care about type theory at all and the whole thing strikes me as programmers larping (poorly) as mathematicians.