TypeScript support

[jaysylvester]

See title.

[Dimava]

I'm interested in trying to try to implement this
Mostly to see how the "old-school app servers" worked

With --experimental-strip-types node doesn't even need anything else to run TS

I'll make a draft PR tomorrow so you're able to see how typescript changes this codebase

I've looked up the code
It uses a lot of ||, are they actually intended to be || or they are intended to be ?? (as || also applies to false so you can't disable stuff on case by case basis)
In some cases there are foo || bar ? a : b which gets parsed as (foo || bar) ? a : b, please add brackets there

[jaysylvester]

The || logic is all correct (no bugs or unexpected behavior as far as I know), but there are probably suboptimal examples (or perhaps code others consider problematic that I don't find objectionable) I've avoided touching because they currently work as expected.

Are you looking to make it compatible with apps written in TS or changing citizen itself to be written in TS?

[Dimava]

I'm "rewriting" it to node-compatible TS (basically just adding variable types)
Then it can compiled back to JS with something like https://bloomberg.github.io/ts-blank-space/ + d.ts if needed

Rewriting + compiling to d.ts is somewhat easier then just adding d.ts as it immediately errors if types don't match