redux-reducer-delegate

A way to create reducers by composing sub-reducers. This prevent the switch statements.

Installation

    npm install redux-reducer-delegate

Usage

import { createReducersMap, createReducerDelegate } from 'redux-reducer-delegate';

/**
 * Note here that you will only return the current state that you would like to replace
 * which is the same how react's setState works. The main reducer that is called by
 * redux will be the one that will merge this state on the current state
 *
 */
export const addTodo = ( { todo }, state ) => {
    if ( todo ) {
        const { todos: currentTodos } = state;
        return { todos: currentTodos.concat(todo) };
    }
};

export const removeTodo = ( { todo }, state ) => {
    const { todos: currentTodos } = state;
    if ( todo ) {
        const idx = currentTodos.indexOf(todo);
        return { todos: [ ...currentTodos.slice(idx), ...currentTodos.slice(idx + 1) ] };
    }
};

/**
 * Create a mapping for the type to handlers
 */
const mapping = createReducersMap([addTodo, removeTodo]);

/**
 * Finally compose the reducer
 */
export const reducer = createReducerDelegate(mapping);

Passing Initial state

createReducerDelegate can use an initial state by passing it as a second argument to createReducerDelegate. By default it is going to return an empty object literal.

createReducerDelegate(mapping, { count: 0 });

Test

npm run test