Required property from React hook form does not validate on textfields

I'm currently using React-hook-form to manage my textfields and that includes validation.
The problem right now is that the required property does not work well, because it does not show the little helpertext under the inputfield when it is empty.
Here is there a snippet of the UI, it only shows a few of the inputfields to save you the
unnecessary JSX code

This is how i have done it:

import { FragmentType, useFragment } from '@gql/fragment-masking';
import { graphql } from '@gql/gql';
import { Gender } from '@gql/graphql';
import {
Button,
Card,
CardContent,
Grid,
MenuItem,
TextField,
TextFieldProps,
Typography,
} from '@mui/material';
import { AdapterDayjs } from '@mui/x-date-pickers/AdapterDayjs';
import { DesktopDatePicker } from '@mui/x-date-pickers/DesktopDatePicker';
import { LocalizationProvider } from '@mui/x-date-pickers/LocalizationProvider';
import dayjs, { Dayjs } from 'dayjs';
import { useTranslation } from 'next-i18next';
import React, { useCallback, useState } from 'react';
import { useForm } from 'react-hook-form';
type Inputs = {
firstName: string;
lastName: string;
birthdate: string;
street: string;
postalcode: string;
city: string;
country: string;
gender: string;
email: string;
leveloftrust: string;
lastsignedin: string;
};
export const PatientInfoFragment = graphql(/* GraphQL */ `
fragment PatientInfo on Patient {
addresses {
city
lines
postalCode
}
birthDate
email
gender
id
name {
firstName
lastName
}
status {
lastSignInAt
levelOfTrust
}
}
`);
interface PatientInfoProps {
patient: FragmentType<typeof PatientInfoFragment>;
}
export function PatientInfo(props: PatientInfoProps) {
const patient = useFragment(PatientInfoFragment, props.patient);
const [value, setValue] = React.useState<Dayjs | null>(
dayjs(patient.birthDate)
);
const genderValueArray = Object.values(Gender);
const [disabled, setDisabled] = useState(true);
const { register, handleSubmit } = useForm<Inputs>({
defaultValues: {
firstName: patient.name?.firstName ?? '',
lastName: patient.name?.lastName ?? '',
birthdate: patient.birthDate ?? '',
country: '',
gender: patient.gender,
email: patient.email ?? '',
leveloftrust: patient.status?.levelOfTrust,
lastsignedin: patient.status?.lastSignInAt,
postalcode: patient.addresses[0]?.postalCode ?? '',
city: patient.addresses[0]?.city ?? '',
street: patient.addresses[0]?.lines[0] ?? '',
},
shouldUseNativeValidation: true,
});
const handleChange = React.useCallback(
(newValue: Dayjs | null) => setValue(newValue),
[]
);
const { t } = useTranslation();
const handleEditClick = useCallback(() => setDisabled(!disabled), [disabled]);
const renderInputField = React.useCallback(
(params: JSX.IntrinsicAttributes & TextFieldProps) => {
return <TextField {...params} />;
},
[]
);
const onSubmit = (data: any) => console.log(data);
return (
<Card>
<CardContent>
<form onSubmit={handleSubmit(onSubmit)}>
<Grid container direction="row" justifyContent="space-between">
<Grid item>
<Typography gutterBottom variant="h5" component="div">
{t('patient.info.title', 'Personal Information')}
</Typography>
</Grid>
<Grid item>
<Grid container justifyContent="space-between" sx={{ m: 1 }}>
{!disabled && (
<Button
onClick={handleEditClick}
size="large"
variant="outlined">
Cancel
</Button>
)}
<Button
onClick={handleEditClick}
size="large"
type="submit"
variant="contained">
{!disabled
? t('patient.setToComplete', 'Set to complete')
: t('patient.edit', 'Edit')}
</Button>
</Grid>
</Grid>
</Grid>
<Grid container direction="row">
<Grid
container
sx={{ margin: 1 }}
rowSpacing={3}
spacing={{ md: 4 }}>
<Grid item>
<TextField
{...register('firstName', { required: 'Field needs to be filled out' })}
label="Name"
name="firstName"
id="component-outlined"
disabled={disabled}
/>
</Grid>
<Grid item>
<TextField
{...register('lastName', {
required: 'Field needs to be filled out',
})}
label="lastname"
name="lastName"
id="component-outlined"
disabled={disabled}
/>
</Grid>
<Grid item sx={{ width: '274.67px' }}>
<LocalizationProvider dateAdapter={AdapterDayjs}>
<DesktopDatePicker
{...register('birthdate', {
required: 'Field needs to be filled out',
})}
label="Birthdate"
inputFormat="MM/DD/YYYY"
value={value}
onChange={handleChange}
renderInput={renderInputField}
disabled={disabled}
/>
</LocalizationProvider>
</Grid>
</Grid>
<Grid
container
sx={{ margin: 1 }}
rowSpacing={3}
spacing={{ md: 4 }}>
<Grid item>
<TextField
{...register('street')}
id="component-outlined"
label="Street"
name="street"
disabled={disabled}
/>
</Grid>
<Grid item>
<TextField
{...register('postalcode')}
id="component-outlined"
label="Postal code"
name="postalCode"
disabled={disabled}
/>
</Grid>
<Grid item>
<TextField
{...register('city')}
id="component-outlined"
label="City"
name="city"
disabled={disabled}
/>
</Grid>
</Grid>
<Grid
container
sx={{ margin: 1 }}
rowSpacing={3}
spacing={{ md: 4 }}>
<Grid item>
<TextField
{...register('country')}
id="component-outlined"
label="Country"
name="country"
disabled={disabled}
/>
</Grid>
<Grid item>
<TextField
sx={{ width: '242.67px' }}
id="outlined-select-gender"
select
{...register('gender')}
label="Gender"
disabled={disabled}
value={patient.gender}>
{genderValueArray.map(option => (
<MenuItem key={option} value={option}>
{option}
</MenuItem>
))}
</TextField>
</Grid>
<Grid item>
<TextField
{...register('email')}
id="component-outlined"
label="Email"
name="email"
disabled
/>
</Grid>
</Grid>
<Grid
container
sx={{ margin: 1 }}
rowSpacing={3}
spacing={{ md: 4 }}>
<Grid item>
<TextField
{...register('leveloftrust')}
id="component-outlined"
label="Level of trust"
name="leveloftrust"
disabled
/>
</Grid>
<Grid item>
<TextField
{...register('lastsignedin')}
id="component-outlined"
label="Last signed in"
name="lastsignedin"
disabled
/>
</Grid>
</Grid>
</Grid>
</form>
</CardContent>
</Card>
);
}

If you're using React Hook Form with MUI Textfield, you'll need to use the Controller component wrapper from react-hook-form for your MUI Textfield components.

View Integrating with UI Libraries

For example, you would grab the Input component from MUI's Core library instead:

import Input from "@material-ui/core/Input";

Then in your form you'd wrap it using Controller like:

<Controller
name="firstName"
control={control}
render={({ field }) => <Input {...field} />}
/>

Then MUI Input has has error boolean and helperText string as available properties on the Input component. For example using Formik (but any form library would work with MUI):

<TextField
id="password"
name="password"
label="Password"
type="password"
value={formik.values.password}
onChange={formik.handleChange}
error={!!formik.errors.password && formik.touched.password}
helperText={formik.touched.password && formik.errors.password}
required
/>

Otherwise, reviewing their documentation on how to Handle Errors, it appears with no library they have you handle error output manually using the errors object from formState. You'd destructure that data like:

const { register, formState: { errors }, handleSubmit } = useForm();

Finally, they link a very handy CodeSandbox which uses a @hookform/error-message library that can wrap regular HTML inputs. If you want to stick with MUI, I'd go with the helperText and error properties.