📎 TypeScript 5.0

[Conaclos]

Description

Add parsing and formatter support for the syntax introduced by TypeScript 5.0

• export type * feat(rome_js_parser): TS 5.0 export type * #4228

  • TypeScript PR
  • TypeScript announcement

• const type parameters

  • TypeScript PR
  • TypeScript announcement

[nissy-dev]

We should support decorators ? Typescript announcement

[Conaclos]

We should support decorators ? Typescript announcement

Updated.

[ematipico]

Personally, I would move decorators to their issue. Why? Because it's not a TypeScript thing but a JavaScript thing.

Having decorators here would send the wrong message: it could signal that we aim to support legacy decorators, which is not our intention.

[csvn]

Personally, I would move decorators to their issue. Why? Because it's not a TypeScript thing but a JavaScript thing.

I think Typescript has one small difference in TS with decorators compared to the spec in TC39 though, they allow decorators before export or export default:

@component('my-foo')
export class Foo {}

@component('my-bar')
export default class Bar {}

Officially in JS this has to be written as:

export @component('my-foo') class Foo {}

export default @component('my-bar') class Bar {}

So I think there may at least be a small difference in syntax parsing/AST between JS/TS.

[ematipico]

@csvn they recently changed the grammar: https://babeljs.io/blog/2023/02/20/7.21.0#decorators-updates

[Conaclos]

@csvn The TypeScript team talks about this change on the spec after discussion between them and the spec team in their TS 5.0 announcement.

[Conaclos]

I opened a new issue #4252 for the support of dcorators.

[csvn]

@ematipico Oh, cool! I did not find that myself when I looked. Glad it's consistent, since it's (IMO) way more ergonomic to have it before export 🙂

[nissy-dev]

I'll take const modifier support.