// actions
const LOGIN = 'LOGIN';

function login(userData) {
    return { type: LOGIN, userData };
}

//reducer
function users(state=[], action) {
    switch (action.type) {
        case LOGIN:
            return [...state, {
                text: 'Login'
            }];
        default:
            return state;
    }
}

// store
let store = createStore(users, {
    username: 'Guest'
});

store.dispatch(login({username: 'th0th', password: '1'}));