import {

  is,

  createStore,

  createEvent,

  createEffect,

  createDomain,

  attach,

} from 'effector'

​

const $store = createStore(null)

const event = createEvent()

const fx = createEffect()

​

const childFx = attach({

  effect: fx,

})

​

is.attached(childFx)

// => true

​

is.attached(fx)

// => false

​

is.attached($store)

// => false

​

is.attached(event)

// => false

​

is.attached(createDomain())

// => false

​

is.attached(null)

// => false