Figma's Journey to TypeScript

• closure-compiler

  15 7,263 9.6 Java

  A JavaScript checker and optimizer.

  

Well, the nice thing with Python types is that the _only_ difference to untyped Python is the type annotations. Last time I worked with TypeScript (two and a half years ago), it felt more like a different language _similar_ to JS. In my experience it was quite... viral. With MyPy I've genuinely seen just specific parts of a code base become typed and didn't notice any friction.

I wonder what would happen if that proposal for type comments in JS went through. Would TypeScript become just a type checker / optimizing compiler?

Google's Closure had an (IMHO) nicer approach (https://github.com/google/closure-compiler/wiki/Types-in-the...), but I don't get the impression it'll ever catch on outside Google.

• JSDoc

  70 14,784 9.3 JavaScript

  An API documentation generator for JavaScript.

  

You may like JSDoc[1] if you just want some type-safety from the IDE without the compilation overhead.

It’s done wonders when I’ve had to wrangle poorly commented legacy JavaScript codebases where most of the overhead is tracing what type the input parameters are.

Personally, I’m impartial to TypeScript or JSDoc at this point. But I’d rather have either over plain JavaScript.

[1] https://jsdoc.app/

• SurveyJS

  surveyjs.io featured

  Open-Source JSON Form Builder to Create Dynamic Forms Right in Your App. With SurveyJS form UI libraries, you can build and style forms in a fully-integrated drag & drop form builder, render them in your JS app, and store form submission data in any backend, inc. PHP, ASP.NET Core, and Node.js.

  

• Scrawl-canvas

  38 313 8.5 JavaScript

  Responsive, interactive and more accessible HTML5 canvas elements. Scrawl-canvas is a JavaScript library designed to make using the HTML5 canvas element easier, and more fun

I don't like Typescript because it forces me to think about types and data structures and stuff. Which is a Good Thing because I absolutely have to think about that stuff when working on large codebases with a team of colleagues: without the inline documentation and text editor help TS gives me when working on those codebases I'd be (at least!) 10x slower when refactoring old code or adding new code. And nobody wants to pay a slow developer!

However ... the one place I refuse to use Typescript is in my side project - a JS canvas library. I can justify this because: 1. it's a big codebase, but I know every line of it intimately having spent the last 10 years (re-)writing it; 2. nobody else contributes (and I kinda like it that way); and 3. I keep a close eye on competing canvas libraries and I've watched several of them go through the immense (frustrating!) work of converting their codebases to TS over the past few years and, seriously, I don't need that pain in my not-paid-for life.

Even so, I do maintain a .d.ts file for the library's 'API' (the functions devs would use when building a canvas using my library) because the testing, documentation and autocompletion help it offers is too useful to ignore. It is additional work, but it's just one file[1] and I can live with that.

[1] https://github.com/KaliedaRik/Scrawl-canvas/blob/v8/source/s...

• skew

  1 378 - JavaScript

  Discontinued A web-first, cross-platform programming language with an optimizing compiler

Skew is open source, but no longer maintained: https://github.com/evanw/skew

• zod

  292 30,778 9.1 TypeScript

  TypeScript-first schema validation with static type inference

This is a very fair comment, and you seem open to understanding why types are useful.

"problems that are due to typing" is a very difficult thing to unpack because types can mean _so_ many things.

Static types are absolutely useless (and, really, a net negative) if you're not using them well.

Types don't help if you don't spend the time modeling with the type system. You can use the type system to your advantage to prevent invalid states from being represented _at all_.

As an example, consider a music player that keeps track of the current song and the current position in the song.

If you model this naively you might do something like: https://gist.github.com/shepherdjerred/d0f57c99bfd69cf9eada4...

In the example above you _are_ using types. It might not be obvious that some of these issues can be solved with stronger types, that is, you might say that "You rarely see problems that are due to typing".

Here's an example where the type system can give you a lot more safety: https://gist.github.com/shepherdjerred/0976bc9d86f0a19a75757...

You'll notice that this kind of safety is pretty limited. If you're going to write a music app, you'll probably need API calls, local storage, URL routes, etc.

TypeScript's typechecking ends at the "boundaries" of the type system, e.g. it cannot automatically typecheck your fetch or localStorage calls return the correct types. If you're casting, you're bypassing the type systems and making it worthless. Runtime type checking libraries like Zod [0] can take care of this for you and are able to typecheck at the boundaries of your app so that the type system can work _extremely_ well.

[0]: https://zod.dev/ note: I mentioned Zod because I like it. There are _many_ similar libraries.

• InfluxDB

  www.influxdata.com featured

  Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.

  

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