createSlice

createSlice(config) is very similar to createSlice in Redux Toolkit As createSlice creates your actions as well as your reducer for you, you don't have to worry about type safety here. Action types can just be provided inline:

// src/app/counter.js
import { createSlice } from 'use-codex';

export const counterSlice = createSlice({
  name: 'counter',
  initialState: {
    value: 0,
  },
  reducers: {
    increment: state => {
      // Codex allows us to write "mutating" logic in reducers. It
      // doesn't actually mutate the state because it uses the Immer library,
      // which detects changes to a "draft state" and produces a brand new
      // immutable state based off those changes
      state.value++;
    },
    decrement: state => {
      state.value--;
    },
    incrementByAmount: (state, action) => {
      state.value += action.payload;
    },
  },
});

export const { increment, decrement, incrementByAmount } = counterSlice.actions;

// The function below is called a thunk and allows us to perform async logic. It
// can be dispatched like a regular action: `dispatch(incrementAsync(10))`. This
// will call the thunk with the `dispatch` function as the first argument. Async
// code can then be executed and other actions can be dispatched
export const incrementAsync = amount => dispatch => {
  setTimeout(() => {
    dispatch(incrementByAmount(amount));
  }, 1000);
};