[Decorators] Missing error when calling addInitializer after that the decorator is done

[nicolo-ribaudo]

🔎 Search Terms

decorators addInitializer error

🕗 Version & Regression Information

• This is the behavior in every version I tried since Stage 3 decorators where implemented

⏯ Playground Link

https://www.typescriptlang.org/play?#code/DYUwLgBAhgJjCSA7AlmZVjIF4gE4DFcB7AWwEYAuCAERAGMjcoxGBhIxMEADzAG0ARLAQo0GbHgEBdANwBYAFCKAZgFdEdNBwgx6ZABQB9KlEQBPADQRN3KrQZMWudpx5gAlBADeiiNDhIqOiYOATE5BAAvNZg3AB0woFiIXjyCgC+iirqmsjaunQATEYm5laGhaVmnj4KfomiwRJhpAb6npEAfN7p7r7WHADORKBxwEQA5voCAILU1ACi1AJ9GVkKdMBQg4MQM979AAIFhUcFZP3KRERREGRpmUoKQA

💻 Code

let addInitializerFrom1: DecoratorContext["addInitializer"];

function dec1(_: any, ctx: DecoratorContext) {
  addInitializerFrom1 = ctx.addInitializer;
}

function dec2(_: any, _2: any) {
  addInitializerFrom1(() => {})
  console.log("ADDED")
}

class A {
  @dec2
  @dec1
  foo = 1;
}

🙁 Actual behavior

The addInitializerFrom1 call should throw

🙂 Expected behavior

addInitializerFrom1 doesn't throw

Additional information about the issue

Spec: https://ci.tc39.es/preview/tc39/ecma262/sha/59003ed603d09485b957a0f579b46697f49a96a6/#sec-applydecoratorstoelementdefinition

After that dec1 is called, decorationState.[[Finished]] for the decorationState relative to dec1 is set to false and thus calling addInitializer should throw.

[nicolo-ribaudo]

Oh there is an open issue about it in the decorators spec, hopefully it will be updated to match TS: tc39/proposal-decorators#500

[rbuckton]

Should this issue be closed? It seems like we'd want to adopt tc39/proposal-decorators#500 if that is approved at the next plenary session.

[nicolo-ribaudo]

Oh right, I closed this assuming that TS already implements the proposed behavior but actually TS throws less than the current spec text and not as proposed in that PR.