Wrong type inference when using response validation for a SSE stream

[fmanzali]

What version of Elysia is running?

elysia 1.4.17 + eden 1.4.5 + openapi 1.4.11

What platform is your computer?

Linux 6.8.0-87-generic x86_64 x86_64

What steps can reproduce the bug?

Run this code to reproduce:

import { treaty } from "@elysiajs/eden";
import { openapi } from "@elysiajs/openapi";
import { Elysia, sse, t } from "elysia";

const model = t.Object({
  value: t.Number(),
});

const app = new Elysia()
  .use(openapi())
  .get(
    "/stream",
    function* () {
      yield sse({
        data: { value: 42 },
      });
    },
    {
      response: {
        200: t.Object({ data: model }),
      },
    }
  )
  .listen(3000);

const api = treaty(app);
const { data } = await api.stream.get();

// TS Error: Type '{ data: { value: number; }; }' must have a '[Symbol.asyncIterator]()' method that returns an async iterator.ts(2504)
// data has type of { data: { value: number; }; } instead of AsyncGenerator
for await (const chunk of data) {
  console.log(chunk);
}

What is the expected behavior?

The type of data is wrapped in a AsyncGenerator.

What do you see instead?

The type of data is just { data: { value: number }}.

Additional information

It's just a TS error: the API works as expected, and the OpenAPI docs are generated correctly.

Have you try removing the node_modules and bun.lockb and try again yet?

Yes

[fmanzali]

Managed to fix this by wrapping the response with t.AsyncIterator:

response: {
        200: t.AsyncIterator(t.Object({ data: model })),
},