"Type instantiation is excessively deep and possibly infinite" and tsc crashing

[fl0ydj]

Describe the bug

First off, thanks for the awesome library!

We have been observing some weird instances of "Type instantiation is excessively deep and possibly infinite". For some files, tsc is even crashing.

Our repo is private so can't share it but we created a couple of custom Fields/components, so maybe you can spot where this is coming from:

1. We have been using zod as a form validator on Fields
2. We wrap all forms in a form context provider to avoid prop drilling and are passing in reference from useRef(form) as we had some problems with stability in earlier versions (not sure if this still makes any difference).
   Code

import type { MutableRefObject } from "react";
import { createContext, useContext } from "react";
import type { useForm } from "@tanstack/react-form";

export const FormContext: React.Context<MutableRefObject<ReturnType<typeof useForm<any>>> | undefined> =
  createContext<MutableRefObject<ReturnType<typeof useForm<any>>> | undefined>(undefined);

export function useFormContext<V>(): ReturnType<typeof useForm<V>> {
  const form = useContext(FormContext) as MutableRefObject<ReturnType<typeof useForm<V>>> | undefined;
  if (!form) {
    throw new Error("useFormContext must be used within a FormProvider");
  }
  return form.current;
}

3. We are using custom fields like in the code below

Code

```javascript type IsDeepValueString> = DeepValue extends string | number | typeof Any ? K : never; type StringDeepKeys = { [P in DeepKeys]: IsDeepValueString; }[DeepKeys]; export const TextField = & StringDeepKeys>( props: { name: N; label?: string; regexPattern?: string; rightElement?: ReactNode; isPassword?: boolean; extraFieldProps?: Omit, "name">; } & Omit, ): ReactNode => { const form = useFormContext(); const { name, label, regexPattern, rightElement, isPassword, ...rest } = props; return ( {(field) => { console.log("ruleAsset", props.name, field.getValue()); return ( 0}> {props.label && {props.label}} { console.log("ruleasset ruleamount change", e.target.value); const regex = new RegExp(props.regexPattern ?? ""); console.log("1"); if (e.target.value === "" || !props.regexPattern || regex.test(e.target.value)) { console.log("2"); //need to cast as we extend string so its not sure it can be assinged properly field.handleChange(e.target.value as DeepValue); console.log("2.1"); } else if (e.target.value === "∞") { field.handleChange(Any as DeepValue); } console.log("3"); }} onBlur={field.handleBlur} {...rest} /> {props.rightElement !== undefined && {props.rightElement}} {field.state.meta.isTouched && field.state.meta.errors?.join(", ")} ); }} ); }; ```

4. We are using some fields where we receive the value from a query. We want to run validation on it and use it with other fields so we decided for the below structure:

Code

```javascript export const GasEstimateSimulation = ({ gasField, metaData, userCoin, approval, }: { gasField: FieldApi; metaData: CoinsData | undefined; userCoin: UserCoin | undefined; approval: Approval; }): ReactNode => { const currentWorkspace = useCurrentWorkspace(); const assets = useAssets(currentWorkspace); const estimatedGas = useEstimateGas(getEstimateGasArgsFromApproval(approval)); console.log("Estimate gas error", estimatedGas, getEstimateGasArgsFromApproval(approval)); useEffect(() => { console.log("setting gas", estimatedGas.data); if (estimatedGas.data !== gasField.getValue()) { gasField.handleChange(estimatedGas.data); } }, [estimatedGas.data, gasField]); return ( ); }; ```

Your minimal, reproducible example

-

Steps to reproduce

See examples above

Expected behavior

Less performance issues with type checking

How often does this bug happen?

None

Screenshots or Videos

No response

Platform

macOs

TanStack Form adapter

None

TanStack Form version

0.26.4

TypeScript version

5.5.4

Additional context

We are using the zod form adaptor at the same version (0.26.4)

[singhparshant]

Following

[Balastrong]

First thing I'd try is to replace the temporary workaround ReturnType<typeof useForm<V>> with the newly exposed ReactFormApi<V>, in other similar cases this helped already with the type issue.

If that doesn't work, could you please reproduce the case on a stackblitz? You can fork one from the docs (e.g. https://tanstack.com/form/latest/docs/framework/react/examples/simple)

---

Speaking of custom components, we've been drafting a possible API and recommended pattern in #825 (component example in https://github.com/TanStack/form/pull/825/files#diff-b2e0803ded7363bf3432f160f7c7f6e9bf4f982ad13b08ecb4789c228774f956). Since you're doing something similar your feedback can help shaping the final version :)

[fl0ydj]

Changed it to ReactFormApi<V> & FormApi<V>. Didn't fix the issue though.

Have been trying to reproduce some of the issues on stackblitz. Have not been able to do so though as it just starts happening once the types are pretty complex. Found one issue, where I had slightly conflicting generics. i.e.:

enum MyEnum {
a,
b,
c
};
type SubEnumType=MyEnum.a|MyEnum.b;

type FormData=FieldValues1&FieldValues2;

type FieldValues1<N extends SubEnumType=SubEnumType>={
fieldVal1:N
}

type FieldValues2={
fieldVal1:MyEnum, //reusing this value here as my field 2 depends on it and consumes it with useStore
fieldVal2: string
}

Changing fieldVal1:MyEnum, to fieldVal1:SubEnumType, solved the error in that situation. I have tried reproducing this in the stackblitz but even this didn't work as presumably my test types were too simple.

Concluding, generally it seems that if the formdata types get too complex, its hard to avoid these ts issues?

Will also give it a couple more tries in the next couple of days

[favna]

I'm also facing this issue in the project where I'm transitioning from Formik to Tanstack Form so I will likewise try to create a reproducible Stackblitz. So far what I can say is that the error occurs on a function I wrote setFormFieldValue:

import type { ReactFormApi, DeepKeys, DeepValue, Updater, Validator, FormApi } from '@tanstack/react-form';

export function setFormFieldValue<TFormData, TField extends DeepKeys<TFormData>>(
  form: FormApi<TFormData, Validator<TFormData, unknown>> & ReactFormApi<TFormData, Validator<TFormData, unknown>>,
  field: TField,
  updater: Updater<DeepValue<TFormData, TField>>
) {
  form.setFieldValue(field, updater);
  form.setFieldMeta(field, {
    errors: [],
    errorMap: { onChange: false },
    isDirty: true,
    isTouched: true,
    isValidating: false,
    isPristine: false
  });
}

Which I call from an onChange to set the value of another field. I noticed that if I only use setFieldValue (without the additional meta) that our Testing Library tests fail because the proper errors aren't shown, coming from this component:

import type { DeepKeys, DeepValue, FieldApi, Validator } from '@tanstack/react-form';

interface FormErrorProps<
  TParentData,
  TName extends DeepKeys<TParentData>,
  TFieldValidator extends Validator<DeepValue<TParentData, TName>, unknown> | undefined = undefined,
  TFormValidator extends Validator<TParentData, unknown> | undefined = undefined,
  TData extends DeepValue<TParentData, TName> = DeepValue<TParentData, TName>
> {
  readonly field: FieldApi<TParentData, TName, TFieldValidator, TFormValidator, TData>;
  readonly 'data-qa'?: string;
}

export function FormError<
  TParentData,
  TName extends DeepKeys<TParentData>,
  TFieldValidator extends Validator<DeepValue<TParentData, TName>, unknown> | undefined = undefined,
  TFormValidator extends Validator<TParentData, unknown> | undefined = undefined,
  TData extends DeepValue<TParentData, TName> = DeepValue<TParentData, TName>
>({ field, 'data-qa': dataQa }: FormErrorProps<TParentData, TName, TFieldValidator, TFormValidator, TData>) {
  if (field.state.meta.isTouched && field.state.meta.errors.length) {
    const message = field.state.meta.errors.at(0);
    const stringMessage = typeof message === 'string' ? message : '';

    if (!stringMessage) return null;

    return <CustomFormNotification message={stringMessage} severity='error' data-qa={dataQa ?? 'form-error'} />;
  }

  return null;
}

The type of the form structure where I call this function is:

enum MyEnum {
  ONE = 'one',
  TWO = 'two'
}

interface MyFormType {
  type: MyEnum;
  amount: number;
  sheetNumber: string | null;
  id: string | null;
}

And it's called like so:

setFormFieldValue(form, 'amount', event.target.value === MyEnum.TWO ? 100 : 20);

With the form being:

  const form = useForm<MyFormType, Validator<MyFormType, unknown>>({
    defaultValues: {
      type: MyEnum.ONE,
      amount: 20,
      sheetNumber: null,
      id: props.id
    },
    onSubmit: ({ value, formApi }) => {
      if (value.type === MyEnum.TWO) {
        value.sheetNumber = null;
      }
      reactQueryHook.mutate(value);

      formApi.reset();
    },
    validatorAdapter: yupValidator()
  });

For the time being I added an @ts-ignore on the line that's giving a problem but I do hope this can get fixed some way.

If it matters, this is my system info:

  System:
    OS: macOS 14.6.1
    CPU: (16) x64 Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
    Memory: 15.67 MB / 32.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 20.16.0 - /private/var/folders/nk/rds5rlv12dn8yxm9qx6mgv0h0000gn/T/xfs-ad6c1b10/node
    Yarn: 4.3.1 - /private/var/folders/nk/rds5rlv12dn8yxm9qx6mgv0h0000gn/T/xfs-ad6c1b10/yarn
    npm: 10.8.1 - ~/.volta/tools/image/node/20.16.0/bin/npm
    pnpm: 9.7.0 - ~/.volta/bin/pnpm

[Spaubleit]

I recreated the most minimal reproduction possible:

import { FormApi, useForm } from "@tanstack/react-form";

const register = <Data,>(form: FormApi<Data>) => {};

const App = () => {
  const form = useForm({
    defaultValues: {
      name: "",
      title: "",
    },
  });

  const x = register(form);

  return null;
};

export default App;

CodeSandbox

It happens in forms with 2 or more fields.

[DaliborHomola]

In my case, this problem was caused by having an interface with a property type Moment. This problem still occurs in the latest version 0.32.0