BlitzServerMiddleware types are incorrect

[Tom MacWright]

What is the problem?

The types for BlitzServerMiddleware specify the response object as simply a ServerResponse

blitz/packages/blitz/src/index-server.ts

Lines 24 to 28 in 0a8d4bf

 export type RequestMiddleware< 
   TRequest extends IncomingMessage = IncomingMessage, 
   TResponse = ServerResponse, 
   TResult = Promise<void> | void, 
 > = { 

But it is not: as the docs lay out, the response object has additional methods, including .send(). So correct code will get incorrectly flagged by TypeScript.

Paste all your error logs here:

PASTE_HERE (leave the ``` marks)

Paste all relevant code snippets here:

app/blitz-server.ts:39:15 - error TS2551: Property 'send' does not exist on type 'ServerResponse<IncomingMessage>'. Did you mean 'end'?

39           res.send({ error: "Bad request", issues: e.issues });
                 ~~~~

What are detailed steps to reproduce this?

1. Create a BlitzServerMiddleware that uses res.send()

Run blitz -v and paste the output here:

placemark-oss on  typescript-5 [$!] via  v18.12.0
➜ y blitz -v
yarn run v1.22.19
$ /Users/tmcw/p/placemark-oss/node_modules/.bin/blitz -v
Blitz version: 2.0.2 (local)
macOS | darwin-arm64 | Node: v18.12.0


 Package manager: npm

  System:
    OS: macOS 14.3
    CPU: (8) arm64 Apple M2
    Memory: 2.32 GB / 24.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 18.12.0 - /var/folders/cs/3sq9lh_j5hjgf9cvbmc8dqkr0000gn/T/yarn--1706981494183-0.4718846359980571/node
    Yarn: 1.22.19 - /var/folders/cs/3sq9lh_j5hjgf9cvbmc8dqkr0000gn/T/yarn--1706981494183-0.4718846359980571/yarn
    npm: 8.19.2 - ~/.volta/tools/image/node/18.12.0/bin/npm
  npmPackages:
    @blitzjs/auth: 2.0.2 => 2.0.2
    @blitzjs/next: 2.0.2 => 2.0.2
    @blitzjs/rpc: 2.0.2 => 2.0.2
    @prisma/client: ^5 => 5.9.1
    blitz: 2.0.2 => 2.0.2
    next: 13.5.6 => 13.5.6
    prisma: ^5 => 5.9.1
    react: ^18.2.0 => 18.2.0
    react-dom: ^18.2.0 => 18.2.0
    typescript: 5 => 5.3.3

Please include below any other applicable logs and screenshots that show your problem:

No response

[Siddharth Suresh]

Thanks for the issue. Will be taking a look.

[Siddharth Suresh]

@tmcw here is a userland quick for now, while we check for a way to make it the default behaviour

+import type {BlitzNextApiResponse} from "@blitzjs/next"
+import type {RequestMiddleware} from "blitz"
+import type {NextApiRequest} from "next"

-BlitzServerMiddleware((req, res, next) => {
+BlitzServerMiddleware<RequestMiddleware<NextApiRequest, BlitzNextApiResponse>>((req, res, next) => {