vimslayer

How much of those IE users are also users of GitHub?

Shipping more modern EcmaScript versions than what's supported by IE has lots of advantages for users whose browsers can support it, so I'd hate it if the IE support came with the expense of everyone else's experience. There are ways to serve different JS bundles for different browsers, of course, but that comes with a maintenance cost for them.

Weird though that some buttons wouldn't work at all, because at least most of the basic functionality seems to work fine with JS disabled even. Maybe they should just disable JavaScript altogether for IE and it'd work better. That should be easy to implement too.

I assume most of the minutes-long compile times they are running into are because of type checking. Moving types to comments wouldn't help that.

I don't konow why they aren't separating type checking and dev builds from each other, but there is just absolutely no way simple TS to modern JS (no compiling to old ES5) conversion would take that long for a 10k LOC project, it must be the type checking. I'm using TS through Babel and it has been a breeze for much larger projects than that. Babel just strips away the TS types and we do type checks via editor integration and a separate CI step. Can't recommend this setup enough.

Elm doesn't need to perform runtime checks (apart from application boundaries like JSON parsing, where runtime checks are performed) because their type system is supposed to be sound, so you can't compile something that would have incorrect types at runtime. Or if you can, that's considered a bug in the compiler. That kind of sound type system has never been a goal for TypeScript.

Note that I'm not saying that Elm would be better than TS or any other language or anything like that, just commenting about the runtime checks. Obviously languages have their strengths and weaknesses (Elm has plenty of both) and TS has had good reasons to go with their design goals.

Most of the project is and will still be written in Rust, a statically typed language, so saying that the "project" will drop static types is an overstatement. Based on the design document where the devs talk about this, the TS code in question is about 10k lines of glue code between Rust & userland JS/TS.