在交换机默认或案例中拦截抛出错误时的不同行为(反应/重复)

我有这个减速机和这两个中间件

...

const reducer  = (
    state = {
        username : '',
        token : '?'
    }, 
    action
) => {
    switch (action.type){
        case 'SET_TOKEN': 
            state = { ...state, token : action.payload }
            break
        case 'SET_USERNAME': 
            state = { ...state, username : action.payload }
            break
        case 'SET_USERNME': 
            throw new Error("Errore, nessuna azione corrispondente")
            break               
    }
    return state
}

const logger = (store) => (next) =>(action) => {

  console.log(store, next, action);
  next(action);

}

const error = (store) => (next) =>(action) => {
  try{
    console.log("Checking errors");
    next(action);
  }catch(e){
    console.log("Error is: " +e);
  }
}

const middleware = applyMiddleware(logger, error);

...

现在,当我向其发送一个操作“SET\u USERNME”时,我会在控制台收到一条错误消息,上面写着:有一个错误,但应用程序继续工作。但我不明白为什么。如果我这样更改交换机部分,我将不再收到控制台消息,而是收到一个错误。

    switch (action.type){
        case 'SET_TOKEN': 
            state = { ...state, token : action.payload }
            break
        case 'SET_USERNAME': 
            state = { ...state, username : action.payload }
            break
        default: 
            throw new Error("Errore, nessuna azione corrispondente")
            break               
    }