Lack of TypeScript documentation - Extending Request / Response / etc.

[CodeSmith32]

Description

Quoting the only documentation within the code for extending the express types:

declare global {
    namespace Express {
        // These open interfaces may be extended in an application-specific manner via declaration merging.
        // See for example method-override.d.ts (https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/method-override/index.d.ts)
        interface Request {}
        interface Response {}
        interface Locals {}
        interface Application {}
    }
}

The URL refers to a piece of code that uses the following syntax:

declare namespace Express {
    export interface Request {
        originalMethod?: string | undefined;
    }
}

This does not work. TypeScript also deprecated namespaces, making this doubly incorrect.

The only correct way I've found of doing this is now:

declare module "express-serve-static-core" {
    export interface Response {
        originalMethod?: string | undefined;
    }
}

There is very little documentation online that shows this, and I cannot find documentation anywhere on expressjs.com for extending these (or for anything at all TypeScript-related, which seems pretty odd to me).

Expectations

I would expect to find adequate documentation on expressjs.com or somewhere that documents usage of express with TypeScript specifically, and that covers extending Request / Response / Locals / Application interfaces in detail, documenting the correct methods that work.

[wesleytodd]

PRs welcome. Ideally over on https://github.com/expressjs/expressjs.com. Thanks!

[bjohansebas]

Wouldn't it be better to move this issue to the repository and not close it?

[wesleytodd]

I do not think there is value in an issue asking for documentation. If they want docs, please open a PR adding the docs.