A
arktype•5d ago
McKamyk

spread and generics

I'm wanting to define a generic, then another generic wrapping and passing through the generic 
const apiResponse = type('<t>', {
  data: 't',
  last_updated: 'number',
})
type ApiResponse<T> = ReturnType<typeof apiResponse.infer<T>>['infer']
// ^ this works fine

const apiPaginatedResponse = type('<t>', {
  '...': apiResponse<t>, // <-- what do I do here?
  cursor: 'null | string'
})
type ApiPaginatedResponse<T> = ReturnType<typeof apiPaginatedResponse.infer<T>>['infer']
const apiResponse = type('<t>', {
  data: 't',
  last_updated: 'number',
})
type ApiResponse<T> = ReturnType<typeof apiResponse.infer<T>>['infer']
// ^ this works fine

const apiPaginatedResponse = type('<t>', {
  '...': apiResponse<t>, // <-- what do I do here?
  cursor: 'null | string'
})
type ApiPaginatedResponse<T> = ReturnType<typeof apiPaginatedResponse.infer<T>>['infer']
4 Replies
ssalbdivad
ssalbdivad•5d ago
Seems like the scoped approach for generics would allow what you're looking for here? https://arktype.io/docs/generics#scoped
McKamyk
McKamykOP•5d ago
Are there some more examples on scoped? I'm looking to build a bunch of models from the api, then wrap them in these response types when I call them, so 
const userSchema = type({ id: 'string', name: 'string' })
const resp = await fetch('/user').then(r => r.json()

const data = apiResponse(userSchema)(resp)
const userSchema = type({ id: 'string', name: 'string' })
const resp = await fetch('/user').then(r => r.json()

const data = apiResponse(userSchema)(resp)
which works fine. Obv use apiPaginatedResponse for paginated data. Is this the right utility? This seems to work... 
const apiResponse = type('<t>', {
  data: 't',
  last_updated: 'number'
})
const apiPaginatedResponse = <T>(of: type.Any<T>) => type({
  '...': apiResponse(of),
  cursor: 'null | number'
})

type ApiResponse<T> = ReturnType<typeof apiResponse.infer<T>>['infer']
type ApiPaginatedResponse<T> = ReturnType<typeof apiPaginatedResponse.infer<T>>['infer']
const apiResponse = type('<t>', {
  data: 't',
  last_updated: 'number'
})
const apiPaginatedResponse = <T>(of: type.Any<T>) => type({
  '...': apiResponse(of),
  cursor: 'null | number'
})

type ApiResponse<T> = ReturnType<typeof apiResponse.infer<T>>['infer']
type ApiPaginatedResponse<T> = ReturnType<typeof apiPaginatedResponse.infer<T>>['infer']
ssalbdivad
ssalbdivad•5d ago
I'm not sure how .infer works on a generic like that for you the property shouldn't be available
McKamyk
McKamykOP•5d ago
cuz I'm grabbing the ReturnType maybe? but everything looks alright

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