`InstanceType` and constructor return type inference doesn’t work for built‑in subtypes of `ErrorConstructor`

🔎 Search Terms

• "ErrorConstructor"
• "InstanceType Error"
• "InstanceType ErrorConstructor"

🕗 Version & Regression Information

• This is the behaviour in every version I tried, and I reviewed the FAQ for entries about this.
• I was unable to test this on prior versions because dtslint only tests back to TypeScript 5.0, and the bug workbench failed to download versions older than TypeScript 4.0.

⏯ Playground Link

https://www.typescriptlang.org/dev/bug-workbench/?#code/CYUwxgNghgTiAEkoGdnwMIFdkBcD2AtgKIwx4zwgAeOIAdsGiWRQN4BQAvu+zgJ4AHBADkiARngBeeAEk6uKHTAgAKoJAAeIgDcoEZuXR55OGJjD4YAPgDc7APT34z+AD0A-D35D4ogExSsiaKympCGgBKigDmIAYwRiZmFuS2Dk4uHl7qvkQAzIFyCkqq6pEgAGYgcCXxibjJlmmOLm6evDmiACyFwSVhmgDKfHQ4UFR1xg3mTXYtme3eIkQArL3FoWUDk0kzqXMZzlkdPqIAbOtj-WUAqhEyO9Mp1getx0sYRJchpeFLeBUMNh8MRSPt0m9PEA

💻 Code

declare class CustomError extends Error {
}

type NE1 = InstanceType<EvalErrorConstructor>;
//    ^?

type NE2 = InstanceType<RangeErrorConstructor>;
//    ^?

type NE3 = InstanceType<ReferenceErrorConstructor>;
//    ^?

type NE4 = InstanceType<SyntaxErrorConstructor>;
//    ^?

type NE5 = InstanceType<TypeErrorConstructor>;
//    ^?

type NE6 = InstanceType<URIErrorConstructor>;
//    ^?

type CE = InstanceType<typeof CustomError>;
//    ^?

Workbench Repro

🙁 Actual behavior

Type query results:

type NE1 = Error
type NE2 = Error
type NE3 = Error
type NE4 = Error
type NE5 = Error
type NE6 = Error
type CE = CustomError

🙂 Expected behavior

Type query results:

type NE1 = EvalError
type NE2 = RangeError
type NE3 = ReferenceError
type NE4 = SyntaxError
type NE5 = TypeError
type NE6 = URIError
type CE = CustomError

Additional information about the issue

Same happens with:

declare function newError<E extends Error>(ctor: new (msg?: string) => E): E;
declare class CustomError extends Error {
}

let ne1 = newError(EvalError);
//   ^?

let ne2 = newError(RangeError);
//   ^?

let ne3 = newError(ReferenceError);
//   ^?

let ne4 = newError(SyntaxError);
//   ^?

let ne5 = newError(TypeError);
//   ^?

let ne6 = newError(URIError);
//   ^?

let ce = newError(CustomError);
//   ^?

Workbench Repro

Related issues

• https://github.com/DefinitelyTyped/DefinitelyTyped/pull/64628#pullrequestreview-1697561855

Beginne mit dem verlinkten Playground-Repro und untersuche, wie die integrierten ErrorConstructor-Typen mit InstanceType und der generischen newError-Deklaration interagieren. Vergleiche die inferierten Typen mit den erwarteten Ergebnissen für EvalError, RangeError, ReferenceError, SyntaxError, TypeError, URIError und CustomError; als erledigt gilt die Aufgabe, wenn die Typabfragen und Konstruktoraufrufe jeden spezifischen Subtyp bewahren.