TC39 proposal - Error.cause property

[sirian]

lib.es2021d.ts Update Request - Error.cause property

Proposal (Stage 3)
https://github.com/tc39/proposal-error-cause

Already implemented in Chrome 93:
https://www.chromestatus.com/feature/5727099325251584

Sample Code

interface Error {
    cause?: any;
}

interface ErrorInit {
    cause?: any;
}

interface ErrorConstructor {
    new(message?: string, init?: ErrorInit): Error;
    (message?: string, init?: ErrorInit): Error;
}

[johanneswuerbach]

Error.cause is also available in Node 16.9.0 now 🎉

[majg0]

Bump

[Alexsey]

Already Stage 4 - the feature is finalized!

[sandersn]

Fixed by #46291 (and #45749, but I missed reviewing that one.)

[amakhrov]

This seems to be partially implemented.

The constructor now accepts ErrorOptions with the cause property - which is great.
However, this property is not declared in the Error object itself.

With the full implementation this example should compile:

const error = new Error("derived", {cause: new Error("original")}); // OK
console.log(error.cause); // Property 'cause' doesn't exist

@sandersn

[sandersn]

Thanks for pointing that out. I re-opened the bug.

[GoudekettingRM]

Bump. Also ran into this. Fixed it local by redeclaring like this:

interface Error {
  name: string;
  message: string;
  cause?: any;
  stack?: string;
}

interface ErrorConstructor {
  new(message?: string, { cause }?: { cause: any }): Error;
  (message?: string): Error;
  readonly prototype: Error;
}

declare var Error: ErrorConstructor

[mcaskill]

I also had this issue for cause and stack. Fixed it by redeclaring like this:

interface ErrorInit {
    cause?: unknown;
}

declare type BaseError = Error;

declare class Error implements BaseError {
    name: string;
    message: string;
    stack?: string;
    cause?: unknown;

    constructor(message?: string, init?: ErrorInit);

    // eslint-disable-next-line @typescript-eslint/ban-types -- Allow catch-all 'function' parameter type.
    static captureStackTrace(error: object, constructor?: Function): void;
}

[yume-chan]

cause was added in #47020 and all definitions had shipped with 4.6.

[MartinJohns]

@yume-chan Although the type is inaccurate, as per #48098.