effector/no-duplicate-on

Disallow duplicate .on-handlers on a particular Store.

const increment = createEvent()

// 👎 which handler should we choose?
// it's better to remove one of them to remove ambiguity
const $badCounter = createStore(0)
  .on(increment, (counter) => counter + 1)
  .on(increment, (counter) => counter + 2)

// 👍 one handler - all is clear and explicit
const $goodCounter = createStore(0).on(increment, (counter) => counter + 1)