我有一個(gè)叫的服務(wù)requestNotificationChannel：app.factory("requestNotificationChannel", function($rootScope) {    var _DELETE_MESSAGE_ = "_DELETE_MESSAGE_";    function deleteMessage(id, index) {        $rootScope.$broadcast(_DELETE_MESSAGE_, { id: id, index: index });    };    return {       deleteMessage: deleteMessage    };});我正在嘗試使用茉莉花對(duì)該服務(wù)進(jìn)行單元測(cè)試："use strict";describe("Request Notification Channel", function() {    var requestNotificationChannel, rootScope, scope;    beforeEach(function(_requestNotificationChannel_) {        module("messageAppModule");        inject(function($injector, _requestNotificationChannel_) {            rootScope = $injector.get("$rootScope");            scope = rootScope.$new();            requestNotificationChannel = _requestNotificationChannel_;        })        spyOn(rootScope, '$broadcast');    });    it("should broadcast delete message notification", function(done) {        requestNotificationChannel.deleteMessage(1, 4);        expect(rootScope.$broadcast).toHaveBeenCalledWith("_DELETE_MESSAGE_", { id: 1, index: 4 });        done();           });});我閱讀了有關(guān)Jasmine中的異步支持的信息，但是由于我對(duì)使用JavaScript進(jìn)行單元測(cè)試相當(dāng)陌生，因此無法使其正常工作。我收到一個(gè)錯(cuò)誤：Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL而且我的測(cè)試執(zhí)行時(shí)間太長(zhǎng)（大約5秒）。有人可以幫助我提供一些可行的代碼示例嗎？