11 ms·

Hey! Author here - let me know if you have any questions about anything in that post (or, you know, anything else... like, erm, Electron).

vmasto 10y ago
I have to ask the obvious, Flow vs TypeScript. I'm sure as React users you took your time weighing the two; care to comment on what drove your final decision?
- felixrieseberg 10y ago
  I'll be careful not to tell anyone not to use Flow - we're using many of Facebook's tools and we're grateful for their gifts to the community. If Flow works for people, that's great! That said, back when we got started, we found that TypeScript is all around a better team player. For us, we found that it worked better with npm modules, different operating systems, vanilla JavaScript, and various coding tools (VIM, Visual Studio Code, Atom, etc).
- MarcusBrutus 10y ago
  I 've used both. Flow wins hands down: (1) It is less intrusive. Flow's type system is built on annotations which are simply stripped away at runtime (as opposed to writing in another - albeit similar - language that gets transpiled to JS. Sure the transformations are always "file-local" as TS folks say but still it is another, totally unecessary level of abstraction and transpilation. (2) Flow's type system is at least equally and quite possibly much more expressive and nuanced than TS. (3) Flow annotations can be applied in a much more piece-meal way than TS. (4) zero issues integrating with 3rd party libraries (because of 1) - and that includes the ability to type-check said 3rd party libraries (which is a breeze with flow-typed) (5) To take advantage of TS you have to write JS code in the "JS with classes" style (a.k.a "JS for C# coders"). In contrast Flow allows you to take advantage of its type checking while coding: (a) in idiomatic JS (prototypes) (b) in JS with classes (c) any combination and mix of the two approaches. Flow feels a lot less opinioned as to your JS programming style. (6) Flow it is not coming from microsoft (but hey, don't you know we've changed, please give us another chance and we won't fuck you over this time, please we love you so). TS team is trying very hard (perhaps too hard) to distance themselves from the negative brand value of microsoft (7) Flow is not a blueprint for the Mother of all embrace-extend-extigunish strategies (see #6).
  - jnordwick 10y ago
    the whole "MS is evil" thing is so played out.
  - nycdotnet 10y ago
    I have not used Flow, but there's a few misconceptions about TypeScript in the above comment. - There's an implication that Flow is vastly different than TypeScript because its annotations are stripped away - that's how TypeScript works too. - There's an implication that TypeScript has some sort of unusual syntax - Modern JavaScript (ES6+) and TypeScript code is identical (except for the addition of type annotations where desired). - Flow may have a nuanced and expressive type system - I don't know - but TypeScript attempts to accurately model the type system of JavaScript. - TypeScript can be used in a very loose mode where it type-checks plain .js files with no annotations at all, all the way up to a very strict mode where it must know the type of everything (which you can set to `any` on a per-variable basis if you don't care). - TypeScript is JavaScript, so it has no issues integrating with any JavaScript library. If you want perfect strong typing of a given version of a given JS library, someone has to do that work and this is where some people do struggle. Microsoft has put forth a lot of effort to help here recently. Flow-type may be a great resource (I don't know), but I can scroll its list of supported libraries on its repo on GitHub. https://github.com/flowtype/flow-typed/tree/master/definitions/npm https://github.com/flowtype/flow-typed/tree/master/definitio... . The DefinitelyTyped repo breaks GitHub with the number of libraries it has definitions for: https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types https://github.com/DefinitelyTyped/DefinitelyTyped/tree/mast... (nearly 2000 entries are omitted). - Item 5 is flatly false. For example, TypeScript is itself written in TypeScript and there is not a class in the entire code base - it is 100% idiomatic functional JS. By contrast, Flow is not self-hosted. - Regarding item 6, TypeScript is the poster child for the new Microsoft. It has been open source (Apache 2.0) and cross platform from its original release in 2012. And regardless of what happens with TypeScript (I forsee it tracking ECMAScript standards for the next several years at a bare minimum), the emitted JS is basically identical to your TypeScript code (minus the annotations) so worst case scenario if Microsoft somehow magically deleted all copies of TypeScript in the world, you'd just keep going with the ES6+ code you have.
scrollaway 10y ago
Less engineering, more practical question: What's your setup? I see vscode screenshots, care to share your typescript config and preferences? :)
- ojkwon 10y ago
  It does have a small additional own flavor of configuration, but basically, it's nearly identical to some of OSS project written in typescript, like RxJS (https://github.com/ReactiveX/rxjs/blob/master/tsconfig.json https://github.com/ReactiveX/rxjs/blob/master/tsconfig.json / https://github.com/ReactiveX/rxjs/blob/master/tslint.json https://github.com/ReactiveX/rxjs/blob/master/tslint.json) cause basically it just inherited those configurations. For VS code preferences, there isn't one unified one but just leave each individual picks configs based on own preferences.
ArchReaper 10y ago
There was a big discussion on Electron today here - https://news.ycombinator.com/item?id=14087381 https://news.ycombinator.com/item?id=14087381 One of the points was talking about React Native vs Electron. What are your thoughts? Why did you guys go with Electron?
- cwyers 10y ago
  Isn't Slack older than React Native for platforms outside of iOS?
35bge57dtjku 10y ago
Have you tried ScalaJs? Typescript seems like a better alternative to plain Js, but still seems pretty lacking. For example, the standard libraries are so much nicer than what TS or Javascript offer.
- kornish 10y ago
  My suspicion is that the ease of porting an existing JS codebase to Typescript is an order of magnitude easier than rewriting it in Scala, even if the eventual benefit is higher.
  - ludicast 10y ago
    I think scala.js is having better integration these days (due to typings etc.) But still not 100%. But I would switch to all-scala if it ever had a dev-friendly 100% integration strategy.
    - 35bge57dtjku 10y ago
      What do you mean by that? It's had the ability for a while now to easily specify types for external js code and call js code.
      - ludicast 10y ago
        I'll have to reexamine then. Last I saw the typings story wasn't well documented but would be beyond overjoyed to be wrong.
- abiox 10y ago
  or Fable, or PureScript, or Kotlin... :)
  - Rapzid 10y ago
    Fable has such potential. F# is fantastic and I could totally get behind that as a TypeScript alternative under the right circumstances.
groovypuppy 10y ago
Hey Felix, was Dart ever in consideration? I use both TS & Dart (I'm on a TS project currently) but I find Dart so much cleaner but the JS code it generates is very hairy. Thoughts?
- felixrieseberg 10y ago
  I personally haven't spent too much time looking at Dart, but I find it pretty suspicious that TypeScript is on Google's list of approved languages for projects, while Dart is interestingly missing. I'm sure there's upsides to Dart, but I would certainly need to spend more time with it to make a judgement call. https://www.reddit.com/r/programming/comments/64e6x7/typescript_got_approved_as_internal_development/ https://www.reddit.com/r/programming/comments/64e6x7/typescr...
  - floitsch 10y ago
    Dart is doing fine inside Google. It is used by extremely important projects, like, for example Adwords. These teams are very happy with it and have no intention of changing. Brad Green already posted a follow-up post on the omission of Dart on his slides: http://angularjs.blogspot.dk/2017/04/official-languages-at-google.html http://angularjs.blogspot.dk/2017/04/official-languages-at-g... (I work on Dart.)
    - felixrieseberg 10y ago
      Thanks for the update, good to know!
    - groovypuppy 10y ago
      Even though I work with Typescript daily, Typescript feels like a stop-gap measure until ES6 /ES.Next take hold. Dart feels like the future - given Fuchsia + Flutter + Android apps in Chrome, etc. - if they can just work out some of the rough edges(e.g. isolates with Flutter) and make it more harmonious with JS/DOM - let's face it: We are stuck with the JS/HTML/CSS stack for the foreseeable future.
  - 10y ago
sydd 10y ago
> To improve our situation, we decided to give static type checking a shot. I wonder why it took you years to realize this. I'd never use a dynamically typed language for more than a few hundred lines of code, it becomes an unmaintainable mess afterwards. So serious question: Why?
- azrazalea 10y ago
  In case you are wondering about the downvotes: There are millions(trillions?) of lines of code out there that is maintainable and dynamically typed.
  - jiaweihli 10y ago
    Maintainable, but at what cost? A large chunk of unit tests for dynamically typed code is dedicated to checking types.
- felixrieseberg 10y ago
  It's probably worth pointing out that Slack _also_ contains a ton of native code, written in C++ (with a bit of C++/CX and Objective-C). All of us on our small team have an extensive background in typed languages, including giant code bases (Windows, for example). We just also happen to really like JavaScript, feeling that it and the ecosystem around us makes us more productive given our needs. TypeScript a few years ago was simply not good enough, and neither were the alternatives. It's okay if you feel otherwise, but trust that there are quite a few developers out there who are comfortable with building and maintaining rather large JavaScript codebases, building pretty impressive applications with it. This post isn't yet another "JavaScript is terrible" rant, I quite like it.
- dilap 10y ago
  I'm right there with you, but dynamically-typed languages still have their advocates (though it seems they're losing out more recently). (I think this is because a lot of the advantages associated with dynamic typing were in fact portable back to statically typed languages. If you're comparing C++98 to Python, the dynamically typed language seems pretty nice. If you're comparing Javascript to Golang or TypeScript, not so much.)
seattle_spring 10y ago
Is the article's hero picture (the Seattle skyline) a hint that you'll be opening an office here soon?
- felixrieseberg 10y ago
  Sorry, I just chose the image because TypeScript's official hero image is a Seattle skyline. I hope I didn't disappoint - I love Seattle though, I can't wait to be back this year for //build.
  - seattle_spring 10y ago
    No worries, was mostly joking! I have a good friend at the SF office and hope to one day work with her again. That can only happen if your team opens some offices up here in the Emerald City :)
z3t4 10y ago
It would be interesting to see examples of bugs you found.

vmasto 10y ago

I have to ask the obvious, Flow vs TypeScript. I'm sure as React users you took your time weighing the two; care to comment on what drove your final decision?

felixrieseberg 10y ago
I'll be careful not to tell anyone not to use Flow - we're using many of Facebook's tools and we're grateful for their gifts to the community. If Flow works for people, that's great! That said, back when we got started, we found that TypeScript is all around a better team player. For us, we found that it worked better with npm modules, different operating systems, vanilla JavaScript, and various coding tools (VIM, Visual Studio Code, Atom, etc).
MarcusBrutus 10y ago
I 've used both. Flow wins hands down: (1) It is less intrusive. Flow's type system is built on annotations which are simply stripped away at runtime (as opposed to writing in another - albeit similar - language that gets transpiled to JS. Sure the transformations are always "file-local" as TS folks say but still it is another, totally unecessary level of abstraction and transpilation. (2) Flow's type system is at least equally and quite possibly much more expressive and nuanced than TS. (3) Flow annotations can be applied in a much more piece-meal way than TS. (4) zero issues integrating with 3rd party libraries (because of 1) - and that includes the ability to type-check said 3rd party libraries (which is a breeze with flow-typed) (5) To take advantage of TS you have to write JS code in the "JS with classes" style (a.k.a "JS for C# coders"). In contrast Flow allows you to take advantage of its type checking while coding: (a) in idiomatic JS (prototypes) (b) in JS with classes (c) any combination and mix of the two approaches. Flow feels a lot less opinioned as to your JS programming style. (6) Flow it is not coming from microsoft (but hey, don't you know we've changed, please give us another chance and we won't fuck you over this time, please we love you so). TS team is trying very hard (perhaps too hard) to distance themselves from the negative brand value of microsoft (7) Flow is not a blueprint for the Mother of all embrace-extend-extigunish strategies (see #6).
- jnordwick 10y ago
  the whole "MS is evil" thing is so played out.
- nycdotnet 10y ago
  I have not used Flow, but there's a few misconceptions about TypeScript in the above comment. - There's an implication that Flow is vastly different than TypeScript because its annotations are stripped away - that's how TypeScript works too. - There's an implication that TypeScript has some sort of unusual syntax - Modern JavaScript (ES6+) and TypeScript code is identical (except for the addition of type annotations where desired). - Flow may have a nuanced and expressive type system - I don't know - but TypeScript attempts to accurately model the type system of JavaScript. - TypeScript can be used in a very loose mode where it type-checks plain .js files with no annotations at all, all the way up to a very strict mode where it must know the type of everything (which you can set to `any` on a per-variable basis if you don't care). - TypeScript is JavaScript, so it has no issues integrating with any JavaScript library. If you want perfect strong typing of a given version of a given JS library, someone has to do that work and this is where some people do struggle. Microsoft has put forth a lot of effort to help here recently. Flow-type may be a great resource (I don't know), but I can scroll its list of supported libraries on its repo on GitHub. https://github.com/flowtype/flow-typed/tree/master/definitions/npm https://github.com/flowtype/flow-typed/tree/master/definitio... . The DefinitelyTyped repo breaks GitHub with the number of libraries it has definitions for: https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types https://github.com/DefinitelyTyped/DefinitelyTyped/tree/mast... (nearly 2000 entries are omitted). - Item 5 is flatly false. For example, TypeScript is itself written in TypeScript and there is not a class in the entire code base - it is 100% idiomatic functional JS. By contrast, Flow is not self-hosted. - Regarding item 6, TypeScript is the poster child for the new Microsoft. It has been open source (Apache 2.0) and cross platform from its original release in 2012. And regardless of what happens with TypeScript (I forsee it tracking ECMAScript standards for the next several years at a bare minimum), the emitted JS is basically identical to your TypeScript code (minus the annotations) so worst case scenario if Microsoft somehow magically deleted all copies of TypeScript in the world, you'd just keep going with the ES6+ code you have.

scrollaway 10y ago

Less engineering, more practical question: What's your setup? I see vscode screenshots, care to share your typescript config and preferences? :)

ojkwon 10y ago
It does have a small additional own flavor of configuration, but basically, it's nearly identical to some of OSS project written in typescript, like RxJS (https://github.com/ReactiveX/rxjs/blob/master/tsconfig.json https://github.com/ReactiveX/rxjs/blob/master/tsconfig.json / https://github.com/ReactiveX/rxjs/blob/master/tslint.json https://github.com/ReactiveX/rxjs/blob/master/tslint.json) cause basically it just inherited those configurations. For VS code preferences, there isn't one unified one but just leave each individual picks configs based on own preferences.

ArchReaper 10y ago

There was a big discussion on Electron today here - https://news.ycombinator.com/item?id=14087381 https://news.ycombinator.com/item?id=14087381 One of the points was talking about React Native vs Electron. What are your thoughts? Why did you guys go with Electron?

cwyers 10y ago
Isn't Slack older than React Native for platforms outside of iOS?

35bge57dtjku 10y ago

Have you tried ScalaJs? Typescript seems like a better alternative to plain Js, but still seems pretty lacking. For example, the standard libraries are so much nicer than what TS or Javascript offer.

kornish 10y ago
My suspicion is that the ease of porting an existing JS codebase to Typescript is an order of magnitude easier than rewriting it in Scala, even if the eventual benefit is higher.
- ludicast 10y ago
  I think scala.js is having better integration these days (due to typings etc.) But still not 100%. But I would switch to all-scala if it ever had a dev-friendly 100% integration strategy.
  - 35bge57dtjku 10y ago
    What do you mean by that? It's had the ability for a while now to easily specify types for external js code and call js code.
    - ludicast 10y ago
      I'll have to reexamine then. Last I saw the typings story wasn't well documented but would be beyond overjoyed to be wrong.
abiox 10y ago
or Fable, or PureScript, or Kotlin... :)
- Rapzid 10y ago
  Fable has such potential. F# is fantastic and I could totally get behind that as a TypeScript alternative under the right circumstances.

groovypuppy 10y ago

Hey Felix, was Dart ever in consideration? I use both TS & Dart (I'm on a TS project currently) but I find Dart so much cleaner but the JS code it generates is very hairy. Thoughts?

felixrieseberg 10y ago
I personally haven't spent too much time looking at Dart, but I find it pretty suspicious that TypeScript is on Google's list of approved languages for projects, while Dart is interestingly missing. I'm sure there's upsides to Dart, but I would certainly need to spend more time with it to make a judgement call. https://www.reddit.com/r/programming/comments/64e6x7/typescript_got_approved_as_internal_development/ https://www.reddit.com/r/programming/comments/64e6x7/typescr...
- floitsch 10y ago
  Dart is doing fine inside Google. It is used by extremely important projects, like, for example Adwords. These teams are very happy with it and have no intention of changing. Brad Green already posted a follow-up post on the omission of Dart on his slides: http://angularjs.blogspot.dk/2017/04/official-languages-at-google.html http://angularjs.blogspot.dk/2017/04/official-languages-at-g... (I work on Dart.)
  - felixrieseberg 10y ago
    Thanks for the update, good to know!
  - groovypuppy 10y ago
    Even though I work with Typescript daily, Typescript feels like a stop-gap measure until ES6 /ES.Next take hold. Dart feels like the future - given Fuchsia + Flutter + Android apps in Chrome, etc. - if they can just work out some of the rough edges(e.g. isolates with Flutter) and make it more harmonious with JS/DOM - let's face it: We are stuck with the JS/HTML/CSS stack for the foreseeable future.
- 10y ago

sydd 10y ago

> To improve our situation, we decided to give static type checking a shot. I wonder why it took you years to realize this. I'd never use a dynamically typed language for more than a few hundred lines of code, it becomes an unmaintainable mess afterwards. So serious question: Why?

azrazalea 10y ago
In case you are wondering about the downvotes: There are millions(trillions?) of lines of code out there that is maintainable and dynamically typed.
- jiaweihli 10y ago
  Maintainable, but at what cost? A large chunk of unit tests for dynamically typed code is dedicated to checking types.
felixrieseberg 10y ago
It's probably worth pointing out that Slack _also_ contains a ton of native code, written in C++ (with a bit of C++/CX and Objective-C). All of us on our small team have an extensive background in typed languages, including giant code bases (Windows, for example). We just also happen to really like JavaScript, feeling that it and the ecosystem around us makes us more productive given our needs. TypeScript a few years ago was simply not good enough, and neither were the alternatives. It's okay if you feel otherwise, but trust that there are quite a few developers out there who are comfortable with building and maintaining rather large JavaScript codebases, building pretty impressive applications with it. This post isn't yet another "JavaScript is terrible" rant, I quite like it.
dilap 10y ago
I'm right there with you, but dynamically-typed languages still have their advocates (though it seems they're losing out more recently). (I think this is because a lot of the advantages associated with dynamic typing were in fact portable back to statically typed languages. If you're comparing C++98 to Python, the dynamically typed language seems pretty nice. If you're comparing Javascript to Golang or TypeScript, not so much.)

seattle_spring 10y ago

Is the article's hero picture (the Seattle skyline) a hint that you'll be opening an office here soon?

felixrieseberg 10y ago
Sorry, I just chose the image because TypeScript's official hero image is a Seattle skyline. I hope I didn't disappoint - I love Seattle though, I can't wait to be back this year for //build.
- seattle_spring 10y ago
  No worries, was mostly joking! I have a good friend at the SF office and hope to one day work with her again. That can only happen if your team opens some offices up here in the Emerald City :)

z3t4 10y ago

It would be interesting to see examples of bugs you found.