redux-duck-immer

Inspired by redux-duck.

Providing redux helpers to implement ducks-modular-redux proposal. And the reducer's state is produced by Immer for immutability.

Installation

yarn add redux-duck-immer

API

Define action types

import { defineType } from 'redux-duck-immer';

/**
 * type ActionType = string;
 *
 * (...actionTypes: string[]): ActionType;
 */
const UPDATE = defineType('UPDATE');
const PREFIXED_UPDATE = defineType('prefix', 'UPDATE'); // 'prefix/UPDATE'

• defineType method receive one or many arguments.
• If multiple arguments are provided, its result should be a string like prefix/UPDATE.

Create action creator

import { createAction } from 'redux-duck-immer';

/**
 * interface Action<P> {
 *   type: ActionType;
 *   payload?: P;
 * }
 *
 * (actionType: ActionType): <P>(payload?: P) => Action<P>;
 */
const update = createAction(UPDATE);

// Dispatch action
dispatch(update('hello world!'));

• createAction method receive just one argument.
• This argument should be the defined action type string.
• It should return a function who will receive the action payload and return a valid (FSA compilant) action object.
• The action creator will receive an optional argument with the action payload.

Create reducer

import { createReducer } from 'redux-duck-immer';

const initialState = {
  message: '',
};

/**
 * interface ActionCases<S, P> {
 *   [actionType: ActionType]: (state: S, action: Action<P>) => void | S;
 * }
 *
 * <S, P: any>(initState: any, cases: ActionCases<S, P>): (state: S, action: Action<P>) => S;
 */
const reducer = createReducer(initState, {
  [UPDATE]: (state, action) => ({
    state.message = action.payload
  }),
});

• createReducer method receive two arguments, both required.
• The first argument is the reducer initial state.
• The second argument is an object with the possible action cases, should use the previously defined action types as keys.
• Each key in the action cases should be a function who will receive the current state and the dispatched action as arguments.
• Reducer state is immutable which protected by Immer. In each action case, Immer will produce the nextState based on the mutations to the draft state.

License

Check LICENSE file for more details.