Value from `mobx-state-tree` not updated on the UI

[Dean (딘)]

Description

While using useObserver in the _app.tsx, the state doesn't get updated on the UI after the action is called.

[nick]

Just leaving this here for tomorrow: http://mobx-store-provider.overfoc.us/

[Dean (딘)]

According to the docs you have to assign the new state in the action like this:

...
.actions((self) => ({
  increaseByOneDay() {
    self.currentDate = self.currentDate.setDate(
      self.currentDate.getDate() + 1
    )
  },