Sealleci
Sealleci
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Aarktype
Created by Sealleci on 2/2/2025 in #questions
How to properly infer the return type of a generic function returning ArkType schemas?
TSv5.8 Playground
4 replies
Aarktype
Created by Sealleci on 2/2/2025 in #questions
How to properly infer the return type of a generic function returning ArkType schemas?
Yes, when I saw the changelog for version 5.8 today, I was extremely excited, as if this update was tailor-made for me (of course, that's just a joke 😉 And that's my workaround now: 
interface ResponseMap {
  'A': AResponse | null
  'B': BResponse | null
  'C': CResponse | null
}
async function myFetch<T extends QueryType>(queryType: T): Promise<ResponseMap[T]> {
  ...
  switch(queryType){
    case 'A': {
      const parsedJson = arkType('string.json.parse').to(
        queryModule.aResponse
      )(rawJson)

      if (!(parsedJson instanceof arkType.errors)) {
        return parsedJson
      }

      break
    }
    case 'B': {...}
    case 'C': {...}
    default:
      break
  }
  return null
}
interface ResponseMap {
  'A': AResponse | null
  'B': BResponse | null
  'C': CResponse | null
}
async function myFetch<T extends QueryType>(queryType: T): Promise<ResponseMap[T]> {
  ...
  switch(queryType){
    case 'A': {
      const parsedJson = arkType('string.json.parse').to(
        queryModule.aResponse
      )(rawJson)

      if (!(parsedJson instanceof arkType.errors)) {
        return parsedJson
      }

      break
    }
    case 'B': {...}
    case 'C': {...}
    default:
      break
  }
  return null
}
4 replies