redux-starter-kit createReducer

map.js

import { createAction, createReducer } from 'redux-starter-kit';

/**
 * Adds marker to the map. Payload: marker data
 */
export const addMarker = createAction('map/add-marker');

/**
 * Toggles marker visibility
 */
export const toggleMarkerVisibility = createAction(
  'map/toggle-marker-visibility',
);

const initialState = {
  markers: [],
  initialLocation: {
    latitude: 49.19522,
    Longitude: 16.60796,
  },
};

export const mapReducer = createReducer(initialState, {
  [addMarker]: (state, action) => {
    const newMarker = action.payload;
    state.markers.push(newMarker);
  },
  [toggleMarkerVisibility]: (state, action) => {
    const index = action.payload;
    const marker = state.markers[index];
    marker.visible = !marker.visible;
  },
});