Вы должны использовать регулярное выражение в событии onChange ввода чисел. Пример кода:
const App = () => (
<div className="app">
<Formik
initialValues={{ email: "", rank: -2 }}
onSubmit={async values => {
await new Promise(resolve => setTimeout(resolve, 500));
alert(JSON.stringify(values, null, 2));
}}
validationSchema={Yup.object().shape({
email: Yup.string()
.email()
.required("Required")
})}
>
{props => {
const {
values,
touched,
errors,
dirty,
isSubmitting,
handleChange,
handleBlur,
handleSubmit,
handleReset,
setFieldValue
} = props;
return (
<form onSubmit={handleSubmit}>
<label htmlFor="email" style={{ display: "block" }}>
Email
</label>
<input
id="email"
placeholder="Enter your email"
type="text"
value={values.email}
onChange={handleChange}
onBlur={handleBlur}
className={
errors.email && touched.email
? "text-input error"
: "text-input"
}
/>
<label htmlFor="email" style={{ display: "block" }}>
Rank
</label>
<input
id="rank"
placeholder="Enter your email"
type="number"
value={values.rank}
onChange={e => {
e.preventDefault();
const { value } = e.target;
const regex = /^(0*[1-9][0-9]*(\.[0-9]*)?|0*\.[0-9]*[1-9][0-9]*)$/;
if (regex.test(value.toString())) {
setFieldValue("rank", value);
}
}}
onBlur={handleBlur}
/>
<button type="submit" disabled={isSubmitting}>
Submit
</button>
</form>
);
}}
</Formik>
</div>
);
render(<App />, document.getElementById("root"));
Ссылка на кодовую ячейку кода: https://codesandbox.io/embed/formik-example-nut8p?fontsize=14&hidenavigation=1&theme=dark