redux-zap-async.js

export default prepareStore(initialState, {
  // Action "incrementAsync" that increments multiple times
  // We're using an async generator to yield multiple partial states
  // and execute asynchronous operations
  async *incrementAsync(n) {
    // We can access the current state with "this"
    // We shouldn't need this too often. It's like thunks' getState()
    console.log('initial count', this.count)

    // Instead of dispatching an action as w're used to with redux-thunk,
    // we can yield a partial state at any moment
    yield { counting: true }

    for (let i = 1; i <= n; i++) {
      // In order to be really asynchronous, we need to increment
      // the current state and not the initial state.
      // We can use a function that takes the state as an argument
      yield state => ({ count: state.count + 1 })

      // Wait for 500ms
      await new Promise(resolve => setTimeout(resolve, 500))
    }

    yield { counting: false }
  }
})