Add snapshot to create copy of state created on trigger

[sergeysova]

Inspired by #95

const $copy = snapshot({
  source: $source,
  clock: trigger,
})

// $copy now containes full copy of initialState

trigger()
// Now created a new copy of $source state

---

const backup = createEvent()
const $source = createStore({ ref: new Map() })
const $copy = snapshot({
  source: $source,
  clock: backup,
  fn: ({ ref }) => ({ ref: new Map(ref.entries()) }),
})

[sergeysova]

Without snapshot method:

const $copy = restore(
  sample($source, backup, ({ref}) => ({ref: new Map(ref.entries())})),
  $source.defaultState
)

[sergeysova]

Just a copy without linking:

const $copy = snapshot({ source: $source })

[igorkamyshev]

It was implemented in #150

[sergeysova]

Released in https://github.com/effector/patronum/releases/tag/v1.2.0-next.2

[igorkamyshev]

Shall we close this discussion?

[sergeysova]

Github doesn't allow closing discussions, only locking.

[sergeysova]

I moved this discussion to category Done, that closed for outside contributors