Make AggregateError generic to represent error types

lib Update Request

Make it possible for an AggregateError to carry a type parameter representing the shape of the items in its errors array, while preserving backwards compatibility using type parameter defaults.

Specifically, the current definition is:

// In lib.es2021.promise.d.ts
interface AggregateError extends Error {
    errors: any[]
}

interface AggregateErrorConstructor {
    new(errors: Iterable<any>, message?: string): AggregateError;
    (errors: Iterable<any>, message?: string): AggregateError;
    readonly prototype: AggregateError;
}

// In lib.es2022.error.d.ts; adds `options` argument.
interface AggregateErrorConstructor {
    new (
        errors: Iterable<any>,
        message?: string,
        options?: ErrorOptions
    ): AggregateError;
    (
        errors: Iterable<any>,
        message?: string,
        options?: ErrorOptions
    ): AggregateError;
}

I'm proposing instead:

// In lib.es2021.promise.d.ts
interface AggregateError<T = any> extends Error {
    errors: T[]
}

interface AggregateErrorConstructor {
    new<T = any>(errors: Iterable<T>, message?: string): AggregateError<T>;
    <T = any>(errors: Iterable<T>, message?: string): AggregateError<T>;
    readonly prototype: AggregateError;
}

// In lib.es2022.error.d.ts
interface AggregateErrorConstructor {
    new<T = any>(errors: Iterable<T>, message?: string,
        options?: ErrorOptions): AggregateError<T>;
    <T = any>(errors: Iterable<T>, message?: string,
        options?: ErrorOptions): AggregateError<T>;
    readonly prototype: AggregateError;
}

Again, the only difference is the addition of a new T parameter defaulting to any (the old value), with the errors key updated from any[] to T[].

Configuration Check

My compilation target is ES2022 and my lib is ["ES2022", "DOM"].

Missing / Incorrect Definition

NA, as the property isn't missing; it's just underspecified.

I think this would be a nice quality of life improvement, esp for code that returns AggregateErrors (sorta analogous to the functional style of returning a Result type) rather than throwing them.

Sample Code

// Current
const x = new AggregateError([new Error("Something something...")]).errors; // type is any[]

// With proposal
const x = new AggregateError([new Error("Something something...")]).errors // type is Error[]

Documentation Link

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/AggregateError/errors

lib.es2021.promise.d.ts と lib.es2022.error.d.ts の AggregateError 宣言から始め、既存のコンストラクターオーバーロードと errors プロパティを、提案されているジェネリック形式と比較します。デフォルトが既存の使用方法を維持すること、推論された errors 型が表現されること、そして両方の宣言の整合性が保たれることを確認してください。