typed-function.ts

import { z } from 'zod'

const MAIN_PAGE = 'main'
const VIDEOS_PAGE = 'videos'

const pages = [MAIN_PAGE, VIDEOS_PAGE] as const

type Page = typeof pages[number]

const pageDefinitions = {
  [MAIN_PAGE]: {
    query: z.object({
      email: z.string(),
    })
  },
  [VIDEOS_PAGE]: {
    query: z.object({
      page: z.number(),
    })
  }
}

type PageKeys = keyof typeof pageDefinitions

const getDefinition = <T extends PageKeys>(key: T): typeof pageDefinitions[T]['query'] => {
  return pageDefinitions[key].query;
}

const useQuery = <T extends PageKeys>(key: T, input: any): z.infer<ReturnType<typeof getDefinition<T>>> => {
  return getDefinition(key).parse(input);
}

const result = useQuery(MAIN_PAGE, {})