As I delve into the world of intersection types to enhance a function with an incomplete definition, I encountered an interesting scenario.
Take a look at this code snippet:
WebApp.connectHandlers.use("/route", (req:IncomingMessage, res:ServerResponse)=>{
//do stuff with req and res
})
I am utilizing a connect middleware called body-parser, which appends a body field to the req Object. This transforms it from just an IncomingMessage to an IncomingMessage with a body field.
Attempting to define an intersection type like this:
interface bodyContent = {
body : {
foo : string
}
type intersectionType = bodyContent & IncomingMessage;
I then adjusted my binding in this manner:
WebApp.connectHandlers.use("/route", (req:intersectionType, res:ServerResponse)=>{
//do stuff with req.body and res
})
However, Typescript continues to flag an error stating that the provided callback does not align with the proper format since use is not defined as such.
How can I expand upon the existing official definition of this software without directly modifying it?
Thank you.
Edit:
In response to inquiries, here is the type definition for use:
use(route: string, fn: HandleFunction)
The definition for HandleFunction is as follows:
type handleFunction = (req: IncomingMessage, res: http.ServerResponse) => void;