ducks.js

ducks.js

export default function createStore(reducer, preloadedState) {
  let state = preloadedState
  let listeners = []
  let dispatching = false

  function getState() {
    return state
  }
  
  function dispatch(action) {
    try {
      dispatching = true
      state = reducer(state, action)
    } finally {
      dispatching = false
    }
     
    for (let i = 0; i < listeners.length; i++) {
      const listener = listeners[i]
      listener()
    }

    return action
  }
  
  function subscribe(listener) {
    listeners.push(listener)
  }
  
  // to initialize state
  dispatch({})
  
  return {
    dispatch,
    subscribe,
    getState
  }
}