[TypeScript] Add generic type parameters to getSimpleValidationResolver

[Gabriel-Malenowitch]

Problem

Fix #11149

The getSimpleValidationResolver function does not currently accept generic type parameters. This prevents developers from strictly typing their form values and validation functions.

When using getSimpleValidationResolver with a specific TypeScript interface, it defaults to FieldValues, causing type mismatches and TypeScript errors when passing the generated resolver to useForm or React Admin form components (like <SimpleForm>).

Solution

I have updated getSimpleValidationResolver and the ValidateForm type definition to accept a generic type parameter <TFormValues extends FieldValues = FieldValues>.

This change allows consumers to specify the exact shape of their form values when creating a validation resolver, ensuring type safety and compatibility with react-hook-form.

How To Test

You can verify the fix by creating a strongly typed form and validation function. The following code should no longer produce TypeScript errors:

import { getSimpleValidationResolver, SimpleForm, TextInput, NumberInput } from 'react-admin';

// 1. Define the interface
interface FormValues {
    name: string;
    email: string;
    age: number;
}

// 2. Define the validator
const validate = (values: FormValues) => {
    const errors: Partial<Record<keyof FormValues, string>> = {};
    if (!values.name) errors.name = 'Required';
    if (!values.email) errors.email = 'Required';
    return errors;
};

// 3. Create the resolver with the generic type
const resolver = getSimpleValidationResolver<FormValues>(validate);

// 4. Use it in a SimpleForm (should not throw TS errors)
export const MyForm = () => (
    <SimpleForm<FormValues> resolver={resolver}>
        <TextInput source="name" />
        <TextInput source="email" />
        <NumberInput source="age" />
    </SimpleForm>
);

[Gabriel-Malenowitch]

Issue Ref #11149

[Copilot]

Pull request overview

This PR adds generic type parameters to the getSimpleValidationResolver function and ValidateForm type to enable better TypeScript support for strongly-typed form validation. This allows developers to specify the exact shape of their form values when creating validation resolvers, ensuring type safety and compatibility with react-hook-form.

Changes:

• Added generic type parameters <TFieldValues, TErrors> to getSimpleValidationResolver
• Updated ValidateForm type to accept generic TFieldValues parameter
• Updated JSDoc example to demonstrate typed validation function usage
• Added type assertions for return values to support the generic types

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[slax57]

Also, I tested your example and I still get a TS error.

Can you double check?

[slax57]

Looks like you are missing some return paths (e.g. line 34 or 46)

[Gabriel-Malenowitch]

Truly, thanks!
Now it is solved:

Commit: 19d910a

export const N = () => {
    // 1. Define the interface
    interface FormValues {
        name: string;
        email: string;
        age: number;
    }

    // 2. Define the validator
    const validateA = (values: FormValues) => {
        const errors: Partial<Record<keyof FormValues, string>> = {};
        if (!values.name) errors.name = 'Required';
        if (!values.email) errors.email = 'Required';
        return errors;
    };

    // 3. Create the resolver with the generic type
    const resolver = getSimpleValidationResolver<FormValues>(validateA);
    return null;
};