Ten Years of TypeScript

This is closer to my opinion.

I write a fair amount of Typescript, but it's frustrating to see it used so ubiquitously, when in a lot of cases it's just not necessary.

A strongly typed language definitely has a place in web UI development though. But my hope is to see it replaced by a WASM based language, or better still, a choice of WASM based languages.

Is there any effort ongoing to add optional type declaration to Javascript? Runtime type info. would make lot of use cases possible.

They messed up with contributions to flow-typed where they were not accepting partially done typings, ie. not having some kind of incubator. People would push stuff, others would fix it. In community run projects you need to focus on low friction, not perfectionism. That killed typing coverage while ts was growing like crazy. Typing coverage worked like magnet for ts vs flow decisions. So it killed flow in effect.

Generally a huge positive. With tools like swc, there's really fast compilation & typechecking now. With --watch, the DX is pretty good but yeah sometes has to be restarted anyways.

A couple not so greats:

Typescript has added a lot fo confusion & chaos to the ESM transition. A lot of typescript code is in ESM style, byt if you pull the package, it outputs cjs or what not. TypeScript 4.8- very recent- is the first to actually have a semi-viable Node.js + ESM story going; being a respectably modern package hasnt even really been possible with typescript until just recently. Not fully typescript's issue, but writing a package.json that fully helps consumers is quite difficult, and there's a lot more to grol.woth typescript in the mix. There's such a long long tail of typescript packages that are going to be the long long hold up for getting to ESM cleanly. It's not that hard to change, but awareness is just low, and friction is high while we are still so stuck-in-the-middle. Typescript makes writing code easy, but outputting a good respectable usable library has been impossible & is still not easy. Woe.

I really hope EcmaScript does get type annotations, which could eliminate so much of the need to compile & let typed code just run untyped, elide so many of these difficult transpilation challenges.

Another major issue for typescript is that it is stil so compile-time focused, that type metadata isnt kept intact. It's wild to have such a vast typing system, but to just throw it all out at compile time. To be fair, object metadata in js has been tied to annotations, which has been long long delayed, a huge struggle for the language, so there's not clear targets for how to output type information, but there have been some goes, some works to add runtime type information to typescript & there's so little follow up, so little engagement. All TypeScript feels like such a sharply more limited less useful less ambitious project than what it should be doing, than what a real language+runtime would be. It feels like typescript lives in the shadow of a much more clear & visible greatness.

I agree that the typescript team should consider using the compiler to extend javascript rather than just supplement it with types. Like you said, there are technically parts of typescript that don't have a direct corollary in js (enums/namespaces), so why not take it a step further and add some of the features that js is missing? The only example where they've really taken that next step is with experimental decorators.

I think in general the js/ts community is starting to realize that if we're going to have all of these build tools, we might as well use them to do more than just format, transpile, and bundle. Svelte has sort of pushed this idea with its abuse of the js label feature (it can detect when a variable is reassigned if you prefix it with the dollar sign label, which is technically not possible with js, even with proxies). There's also React Forget, which is promising to completely rewrite components at compile-time to avoid all of the gotchas that hooks have (and improve performance) [1].

In terms of making all of ts erasable, you can technically just write all your type definitions using js-doc comments, in which case the compiler can just be run with the --noEmit flag, and then the code is fully valid js without any modifications.

[1] https://www.youtube.com/watch?v=lGEMwh32soc