a.js

import React from 'react'
import { useStore } from 'effector-react'
import { createStore, createEvent } from 'effector'

// events.js
const emailChanged = createEvent('Email changed')
const passwordChanged = createEvent('Password changed')
const submitPressed = createEvent('Submit pressed')

// stores.js
const $email = createStore('')
  .on(emailChanged, (_, next) => next)

const $password = createStore('')
  .on(passwordChanged, (_, next) => next)

const $authForm = createStoreObject({ email: $email, password: $password })

// EmailInput.js
const EmailInput = () => {
  const email = useStore($email)
  
  return <input value={email} onChange={evt => emailChanged(evt.target.value)} />
}

// PasswordInput.js
const PasswordInput = () => {
  const password = useStore($password)
  
  return <input value={password} onChange={evt => passwordChanged(evt.target.value)} />
}

// AuthForm.js
const AuthForm = () => {
  return <form onSubmit={submitPressed}>
    <EmailInput />
    <PasswordInput />
    <button>Submit</button>
  </form>
}