`query.batch.set` is not a function

[bhuynhdev]

Describe the bug

Intention: Do granular update/override for each "item" in a query.batch → I use the following weather.remote.ts where getTemp is a query.batch and updateTemp try to use getTemp.set to update the value granularly

Issue: The TypeScript type allows me to do getTemp(city).set(). However, upon runtime, there is error

[500] POST /
TypeError: getTemp(...).set is not a function    at eval (src/routes/weather.remote.ts:18:22)

// File: src/weather.remote.ts
import { query, command } from '$app/server';

const WEATHER = [
  { city: 'London', temp: 10 },
  { city: 'Bangkok', temp: 20 },
];

export const getTemp = query.batch('unchecked', async (cities: any[]) => {
  const lookup = new Map(WEATHER.map((w) => [w.city, w]));
  return (city: string) => lookup.get(city)!.temp;
});

export const updateTemp = command('unchecked', async (payload: any) => {
  const { city, newTemp } = payload;
  const record = WEATHER.find((w) => w.city === city);
  if (record) {
    record.temp = newTemp;
    getWeather(city).set(newTemp); // Runtime error but no TS error !!
  }
});

Expectation: Either query.batch.set is allowed and works, or the TypeScript should not allow it. (I do hope it's the former so I can granularly update my batch)

Reproduction

https://stackblitz.com/edit/sveltejs-kit-template-default-7yljcosr

Logs

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 20.19.1 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.8.2 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/bin/pnpm
  npmPackages:
    @sveltejs/adapter-auto: ^6.1.1 => 6.1.1 
    @sveltejs/kit: ^2.43.8 => 2.43.8 
    @sveltejs/vite-plugin-svelte: ^6.2.1 => 6.2.1 
    svelte: ^5.39.8 => 5.39.8 
    vite: ^7.1.9 => 7.1.9

Severity

annoyance

Additional Information

No response