loginformstate with validators

formstate.ts

import { FormState, FieldState } from 'formstate';

export default class LoginFormState {
  username = new FieldState('').validators((val) => !val && 'username required');
  password = new FieldState('').validators((val) => !val && 'password required');
  form = new FormState({
    username: this.username,
    password: this.password
  });

  onSubmit = async () => {
    const res = await this.form.validate();
    if (res.hasError) {
      console.log(this.form.error);
      return;
    }
  };
}