📎 Implement the new resource managment proposal

[ematipico]

Description

Context https://github.com/tc39/proposal-explicit-resource-management

Tests for formatter: https://github.com/prettier/prettier/pull/14862/files

Syntax:

using resource = await instance.lock();
//^^^ new grammar

using is just a new variable kind, so it will be very straight forward to implement it.

[nissy-dev]

I'll take this issue!

[nissy-dev]

As I started working on this task, I found that using declaration is easy, but wait using declaration is difficult to implement.

I've tried defining it like this for babel (see: babel/babel#15520), but it doesn't seem to work

JsForVariableDeclaration =
	kind_token: ('var' | 'let' | 'const' | 'using' | 'await using')
	declarator: JsVariableDeclarator

I'm having trouble figuring out how to handle await using.

[ematipico]

You can develop feature progressively if you prefer.

Here you can check the semantic changes to the language: https://arai-a.github.io/ecma262-compare/?pr=3000 (on the right there's a small widget with arrows, you click them and jump to the next difference).

We start by:

• investigating how babel and TS are doing it, if they are adding new nodes to support the new syntax
• investigating the TC39 changes to the language and what they added/changes
• discuss here the changes, no need to jump coding straightaway

[arendjr]

Any progress on this issue? If I have some time left, I might be able to offer some help.

[ematipico]

Hi @arendjr , thank you! Feel free to help. There hasn't been any update, so feel free to take it

[ematipico]

@arendjr heads up, @nissy-dev opened a PR. If you're still interested, we can all work at helping him to ship the feature and fix regressions as we go

[arendjr]

Great! I had made a small start already, but that’s no problem. It should put me in a good position to give a review at least.