useFieldArray.ts:37 --> error in dev

Describe the bug I just migrated to react-hook-form version >=9.10, and my code is not working anymore, because of the line src/useFieldArray.ts:37

The reported error is: TypeError: Cannot use ‘in’ operator to search for ‘id’ in name1

  34 | ): Partial<ArrayField<TFieldArrayValues, TKeyName>>[] => {
  35 |   if (process.env.NODE_ENV !== 'production') {
  36 |     for (const value of values) {
> 37 |       if (!!value && keyName in value) {
  38 |         console.warn(
  39 |           `📋 useFieldArray fieldValues contain the keyName \`${keyName}\` which is reserved for use by useFieldArray. https://react-hook-form.com/api#useFieldArray`,
  40 |         );

I don’t quite understand why, but it applies the “in” operator on the array item, and not on the array itself. I suspect it comes from the form of my data which are structured as:

{
   "names":{
      "en":["name1", "name2", "name3"]
   }
}

I suspect that the code is now faulty because you expect to get “object” inside the array, but my data aren’t structure that way. can you fix the code to check first if “value” is of type object ?

Thanks in advance, Loic

[parties]

@bluebill1049 can we get an explanation as to why flat arrays aren’t supported? This seems like a pretty crucial feature…

Quick explanation of what I’m trying to do:

• I’m building a bridge from a GraphQL schema to a react-hook-form (in short, auto-generating a form from a GraphQL schema).
• Our schemas use lists of scalars such as string arrays, float arrays, etc. and we want these to be handled by react-hook-form.
• Unfortunately, given this constraint of not supporting flat arrays we have to come up with some kind of workaround where we map our flat arrays into non-flat arrays with id/value combos.

Any advice on how to proceed?

[k-one-o-two]

Are there any plans to support flat arrays?