Awesome

reduce-reducers

Reduce multiple reducers into a single reducer from left to right

Install

npm install reduce-reducers

Usage

import reduceReducers from 'reduce-reducers';

const initialState = { A: 0, B: 0 };

const addReducer = (state, payload) => ({ ...state, A: state.A + payload });
const multReducer = (state, payload) => ({ ...state, B: state.B * payload });

const reducer = reduceReducers(initialState, addReducer, multReducer);

const state = { A: 1, B: 2 };
const payload = 3;

reducer(state, payload); // { A: 4, B: 6 }

FAQ

Why?

Originally created to combine multiple Redux reducers that correspond to different actions (e.g. like this). Technically works with any reducer, not just with Redux, though I don't know of any other use cases.

What is the difference between reduceReducers and combineReducers?

This StackOverflow post explains it very well: https://stackoverflow.com/a/44371190/5741172