must be an instance of FormData (was object)

Hello! This code:

const formData = await request.clone().formData();

const formSchema = type({
    name: 'string>0',
    surname: 'string>0'
})

const parseForm = type('parse.formData').pipe(formSchema)

const formResult = parseForm(formData)

const formData = await request.clone().formData();

const formSchema = type({
    name: 'string>0',
    surname: 'string>0'
})

const parseForm = type('parse.formData').pipe(formSchema)

const formResult = parseForm(formData)

Throws following error:

must be an instance of FormData (was object)

must be an instance of FormData (was object)

However, formData is instanceof FormData and the log also says it's FormData:

ArkError {
  input: {
    code: 'proto',
    description: 'an instance of FormData',
    proto: [class FormData]
  },
  ' arkKind': 'error',
  path: [],
  data: FormData { name: 'Plat', surname: '' },
...

ArkError {
  input: {
    code: 'proto',
    description: 'an instance of FormData',
    proto: [class FormData]
  },
  ' arkKind': 'error',
  path: [],
  data: FormData { name: 'Plat', surname: '' },
...

What am I doing wrong?

27 Replies

ssalbdivad•2mo ago

What did you see that makes you sure it's an instance of FormData? Try just creating it from new FormData() instead and see if that works

PIat•2mo ago

I did console.log(formData)

ssalbdivad•2mo ago

Did you try it with:

const formData = new FormData()

const formData = new FormData()

I need something I can actually repro

PIat•2mo ago

This throws the same error

const formSchema = type({
    name: 'string>0',
    surname: 'string>0'
})
            
const parseForm = type('parse.formData').pipe(formSchema)    

const data = new FormData()

data.append('name', 'Plat')
data.append('surname', '')

const formResult = parseForm(data)

const formSchema = type({
    name: 'string>0',
    surname: 'string>0'
})
            
const parseForm = type('parse.formData').pipe(formSchema)    

const data = new FormData()

data.append('name', 'Plat')
data.append('surname', '')

const formResult = parseForm(data)

ssalbdivad•2mo ago

Works for me

PIat•2mo ago

Aw :( Well, parse.number works inside of this package, but now it's formData

ssalbdivad•2mo ago

I mean it would be one thing if it was unresolvable like before but you're saying this time that it's not an instanceof FormData but that's not the error I get

PIat•2mo ago

ssalbdivad•2mo ago

Can you just show me the error message .toString() like I did?

PIat•2mo ago

ssalbdivad•2mo ago

You get that even if you just pass new FormData() directly to the validator?

PIat•2mo ago

Yes, as per the first picture I'm on Node 20.14.0 Typescript 5.5.3 Arktype 2.0.0-beta.5

ssalbdivad•2mo ago

May as well try beta.6 I can't repro it with those exact versions

PIat•2mo ago

I tried the latest version, also installed it at the root of the workspace, so that there would only be one installation of Arktype, still the same error

ssalbdivad•2mo ago

I tried my best to repro it you will have to link me a repo/branch I can clone

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must be an instance of FormData (was object)