react-hook-form/app/src/setValueWithSchema.tsx

import React, { useEffect } from 'react';
import { useForm } from 'react-hook-form';
import * as yup from 'yup';
import { yupResolver } from '@hookform/resolvers/yup';

let renderCounter = 0;

const validationSchema = yup
  .object()
  .shape({
    lastName: yup.string().min(10).required(),
    firstName: yup.string().min(10).required(),
    requiredField: yup.string().required(),
  })
  .required();

const SetValueWithSchema: React.FC = () => {
  const {
    register,
    setValue,
    handleSubmit,
    formState: { errors },
  } = useForm<{
    firstName: string;
    lastName: string;
    age: string;
    checkbox: boolean;
    radio: string;
    select: string;
    multiple: string[];
    requiredField: string;
  }>({
    resolver: yupResolver(validationSchema),
  });

  renderCounter++;

  useEffect(() => {
    register('firstName', { required: true });
    register('lastName', { required: true });
  }, [register]);

  return (
    <form
      onSubmit={handleSubmit((d) => {
        console.log(d);
      })}
    >
      <input
        name="firstName"
        placeholder="firstName"
        onChange={(e) => {
          setValue('firstName', e.target.value, {
            shouldValidate: true,
            shouldDirty: true,
          });
        }}
      />
      {errors.firstName && <p>firstName error</p>}

      <input
        name="lastName"
        placeholder="lastName"
        onChange={(e) => {
          setValue('lastName', e.target.value, {
            shouldValidate: true,
            shouldDirty: true,
          });
        }}
      />
      {errors.lastName && <p>lastName error</p>}

      <input
        {...register('age')}
        onChange={(e) => {
          setValue('age', e.target.value, {
            shouldValidate: true,
            shouldDirty: true,
          });
        }}
      />

      <input placeholder="requiredField" {...register('requiredField')} />
      {errors.requiredField && <p>RequiredField error</p>}

      <button
        type="button"
        id="setValue"
        onClick={() => {
          setValue('requiredField', 'test123456789', {
            shouldValidate: true,
            shouldDirty: true,
          });
        }}
      >
        firstName reset
      </button>

      <button id="submit">Submit</button>
      <div id="renderCount">{renderCounter}</div>
    </form>
  );
};

export default SetValueWithSchema;