src/reducers/messages.js

// @ts-check
import { MESSAGE_ADD, MESSAGE_QUEUE } from '../actionTypes';

const initialState = {
    messages: [],
    messageQueue: []
};
/**
 * @ignore
 */
export default (state = initialState, action) => {
    switch (action.type) {
        case MESSAGE_ADD:
            return {
                ...state,
                messages: [...state.messages, action.payload],
                messageQueue: state.messageQueue.filter(message => message !== action.payload)
            };
        case MESSAGE_QUEUE:
            return { ...state, messageQueue: [...state.messageQueue, action.payload] };
        default:
            return state;
    }
};