How to extend and use an extended Request type in Typescript / Express?

George C. Norris — Thu, 17 Sep 2020 20:47:51 +0000

I'm adding a BUNCH of middleware libraries that extend the Request Object. I.E. One added user to req. Another add cookie() to req. Another add csrfToken() to req. etc..

When I add a request handler function, how do I tell that function to use the req with all the bells and whistles added by middleware?

Do I hunt down every DefinitelyTyped package corresponding to the middleware? If so, then will the Request type be magically 'decorated` with these properties?

To make it even harder, I've written my own middleware that adds properties to Request

req.myCustomFunction()

In this case, will I need to declare, and extend the Request myself with myCustomFunction?

In addition, will that Request which I am extending 'include' the types given by DefinitelyTyped?

declare namespace Express { export interface Request { myCustomFunction: () => void } }

Will this now include ALL the properties included via DefinitelyTyped AND my myCustomFunction?

How do I reference this interface when using?

Will it be Express.Request? Or just Request?

If I reference it as Request, how does Typescript know to use "my" Request and not the one exported by Express's DefinitelyTyped library?

`
declare namespace Express {
export interface Request {
import_destination?: string;
isZipImport?: boolean;
method: string;
originalname: string;
unzippedPath?: string;
url: string;
user?: TUser;
}

DOES NOT WORK

declare module global { interface Request { file?: FileObj; files?: FileObj[]; user?: TUser; isZipImport?: boolean; unzippedPath?: string; } }`
DOES NOT WORK

` declare global { declare module 'express' { export interface Request { file?: FileObj; files?: FileObj[]; user?: TUser; isZipImport?: boolean; unzippedPath?: string; } } } `

DOES NOT WORK

`
declare namespace Express {
export interface Request {
user?: TUser;
isZipImport?: boolean;
unzippedPath?: string;
}
}




DOES NOT WORK


I'm seriously pulling my hair out trying to get this work. 
WHY WHY WHY.. is this so complicated to make work????

DEV Community: George C. Norris

How to extend and use an extended Request type in Typescript / Express?