Type error when passing field from `useForm(formOptions(...))` to `AnyFieldApi` prop

[Bladesheng]

Describe the bug

When I try to pass field object (FieldApi) to prop of type AnyFieldApi I get a type error. It only happens when the form object from useForm was created using the formOptions function.

TS2322: Type
FieldApi<{ firstName: string; }, "firstName", string, FieldValidateOrFn<{ firstName: string; }, "firstName", string> | undefined, ({ value }: { value: string; fieldApi: FieldApi<{ ...; }, ... 21 more ..., any>; }) => "A first name is required" | ... 1 more ... | undefined, ... 17 more ..., never>
is not assignable to type AnyFieldApi
The types of form.options.listeners are incompatible between these types.
Type 'FormListeners<{ firstName: string; }, FormValidateOrFn<{ firstName: string; }> | undefined, FormValidateOrFn<{ firstName: string; }> | undefined, FormAsyncValidateOrFn<...> | undefined, ... 7 more ..., never> | undefined' is not assignable to type 'FormListeners<any, any, any, any, any, any, any, any, any, any, any, any> | undefined'.
Type 'FormListeners<{ firstName: string; }, FormValidateOrFn<{ firstName: string; }> | undefined, FormValidateOrFn<{ firstName: string; }> | undefined, FormAsyncValidateOrFn<...> | undefined, ... 7 more ..., never>' is not assignable to type 'FormListeners<any, any, any, any, any, any, any, any, any, any, any, any>'.
Types of property onChange are incompatible.
Type '((props: { formApi: FormApi<{ firstName: string; }, FormValidateOrFn<{ firstName: string; }> | undefined, FormValidateOrFn<{ firstName: string; }> | undefined, ... 8 more ..., never>; fieldApi: AnyFieldApi; }) => void) | undefined' is not assignable to type '((props: { formApi: FormApi<any, any, any, any, any, any, any, any, any, any, any, any>; fieldApi: AnyFieldApi; }) => void) | undefined'.
Type '(props: { formApi: FormApi<{ firstName: string; }, FormValidateOrFn<{ firstName: string; }> | undefined, FormValidateOrFn<{ firstName: string; }> | undefined, ... 8 more ..., never>; fieldApi: AnyFieldApi; }) => void' is not assignable to type '(props: { formApi: FormApi<any, any, any, any, any, any, any, any, any, any, any, any>; fieldApi: AnyFieldApi; }) => void'.
Types of parameters props and props are incompatible.
Type '{ formApi: FormApi<any, any, any, any, any, any, any, any, any, any, any, any>; fieldApi: AnyFieldApi; }' is not assignable to type '{ formApi: FormApi<{ firstName: string; }, FormValidateOrFn<{ firstName: string; }> | undefined, FormValidateOrFn<{ firstName: string; }> | undefined, ... 8 more ..., never>; fieldApi: AnyFieldApi; }'.
The types of formApi.options.listeners are incompatible between these types.
Type 'FormListeners<any, any, any, any, any, any, any, any, any, any, any, any> | undefined' is not assignable to type 'FormListeners<{ firstName: string; }, FormValidateOrFn<{ firstName: string; }> | undefined, FormValidateOrFn<{ firstName: string; }> | undefined, FormAsyncValidateOrFn<...> | undefined, ... 7 more ..., never> | undefined'.
Type 'FormListeners<any, any, any, any, any, any, any, any, any, any, any, any>' is not assignable to type 'FormListeners<{ firstName: string; }, FormValidateOrFn<{ firstName: string; }> | undefined, FormValidateOrFn<{ firstName: string; }> | undefined, FormAsyncValidateOrFn<...> | undefined, ... 7 more ..., never>'.
Type any is not assignable to type never

Your minimal, reproducible example

https://stackblitz.com/edit/vitejs-vite-qffrfz9w?file=src%2FApp.tsx

Steps to reproduce

1. Open stackblitz repro.
2. See the type error you get when you try to pass field object to field prop of FieldInfo component.
3. Delete onSubmit handler from formOptions.
4. The type error is gone.

Also, if you take the stuff you pass into formOptions and directly pass it to useForm, (skipping formOptions completely) there is no type error. But I need to reuse the options in other useForm calls.

The repro code is the example from https://tanstack.com/form/latest, when you scroll all the way down. I just moved the options to formOptions instead of passing them directly to useForm.

Expected behavior

The type error should not happen when onSubmit handler is present in formOptions.

How often does this bug happen?

Every time

Screenshots or Videos

Platform

rocky linux, chrome 139

TanStack Form adapter

react-form and svelte adapter. I didn't check other frameworks.

TanStack Form version

^1.23.5

TypeScript version

~5.9.3

Additional context

[LeCarbonator]

I believe the same issue arises with listeners if they were added to formOptions. It ends up being because of how formOptions is typed.

Thanks for the report!

[LeCarbonator]

Checking out possible solutions with #1964

[ThrowingSpoon]

If it helps anyone, using @Bladesheng's example I managed to calm the type error by splitting out the options passed to formOptions() like this:

import {
  type AnyFieldApi,
  formOptions,
  type FormValidateFn,
  useForm,
} from '@tanstack/react-form';

const defaultValues = { firstName: '' };

const onSubmit: FormValidateFn<typeof defaultValues> = async ({
  value,
}) => {
  console.log(value);
};

const formOpts = formOptions({
  defaultValues,
  onSubmit,
});

export default function App() {
  const form = useForm({ ...formOpts });
...

Where the defaultValues, onSubmit, and call to formOptions() could be in their own file. I am unsure if there's any downside here, please let me know if you can foresee any issues with this.

I hope this meets the "reuse" requirement you mentioned here @Bladesheng:

Also, if you take the stuff you pass into formOptions and directly pass it to useForm, (skipping formOptions completely) there is no type error. But I need to reuse the options in other useForm calls.

[LeCarbonator]

I'll look into it! @ThrowingSpoon