improvements for non-experimental decorator types

ファイルもテストも指定されていません。まず既存の DecoratorContext 宣言と、それが対象とする decorator の型定義を見つけ、次に提案されている DecoratedValue のメンバーを現在の型システムと比較してください。合意された catch-all の値型が追加され、生成される JavaScript や既存の動作を変更していなければ完了です。

🔍 Search Terms

github typescript decorator value type

✅ Viability Checklist

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
• This isn't a request to add a new utility type: https://github.com/microsoft/TypeScript/wiki/No-New-Utility-Types
• This feature would agree with the rest of our Design Goals: https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals

⭐ Suggestion

This is a request to add a new utility type because TypeScript added one for decorator contexts but not for values

The DecoratorContext type is nice for catching all context types:

function decorator(value: unknown, context: DecoratorContext) { // optionally use a more specific type.
  // ...
}

But for value, there is not a good catch-all type.

📃 Motivating Example

If we have a context catch all type, why not also have a value catch all type, f.e. something like :

export type DecoratedValue = Constructor | Function | ClassAccessorDecoratorTarget<object, unknown> | undefined

💻 Use Cases

1. What do you want to use this for? decorators whose code handles any value type
2. What shortcomings exist with current approaches? we have to make the catchall for value ourselves, but we don't have to do that for context
3. What workarounds are you using in the meantime? I make my own catchall (not that big a deal, but neither would making DecoratorContext myself be