Bridging the tooling gap with Scala.js

Scala.js is a tool for compiling your Scala code to JavaScript. This enables writing type-safe and robust front-end application, but have you ever considered what it can do for Scala tooling? In this talk we’ll see how Scala.js can bridge the gap between the Scala-based and the JavaScript-based tools we use every day as programmers.

Transcript

1. Bridging the tooling gap with Scala.js
2. me, hi!
3. stuff I do
4. Let's talk about JavaScript
5. '' == false // true [''] == '' // true [[]] == 0 // true typeof document.all // undefined document.all === undefined // false document.all === null // false document.all == null // true Number.MIN_VALUE > 0 // true ['1','2','3'].map(parseInt) // [1, NaN, NaN]
6. Built with JS desktop apps
7. Built with JS mobile apps
8. Built with JS backends
9. Oh, right, and the
10. It matters (like it or not)
11. A story
12. Mythical Trees and where to find them
13. AST Explorer
15. First idea +-------------------------+ +------------------------+ | | | | | | | | | | | | | | source | | | +---------------------------------------> | | | | | | | | | | | | | | | AST EXPLORER | | JVM SERVER | | | | | | | AST | (SCALAMETA) | | | <---------------------------------------+ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +-------------------------+ +------------------------+
16. downsides 4 loading time 4 extra infra
17. Write a parser from scratch
18. Scala.js?
19. Scala.js!
21. Benefits 4 ! fast 4 ☁ no extra infra demo
22. Fast forward a few weeks
24. First idea +-------------------------+ +------------------------+ | | | | | | | | | | | | | | source | | | +---------------------------------------> | | | | | | | | | | | | | | | VSCODE | | SCALAFMT CLI | | | | | | | formatted source | (JVM) | | | <---------------------------------------+ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | +-------------------------+ +------------------------+
25. Downsides 4 ! slow (for a single file) 4 " not self-contained
26. Scala.js?
27. Yep
28. Upsides 4 ! fast 4 " self-contained Downsides 4 ! config -> cross-platform HOCON is still meh
29. Free ideas, grab them! 4 scalafmt on astexplorer.net 4 (alternatively) standalone playground on scalafmt.org 4 browser extension that formats code comments 4 scalafmt on scala native 4 GitHub app for scalafmt checks (talk to @laughedelic)
30. Thanks