Jasmine测试ng Promises - Provide and Spy

jasmine提供了很多些很实用的处理Promises的方法，首先我们来考虑下面的这个例子：

    angular.module("myApp.store").controller("StoresCtrl", function($scope, StoreService, Contact) {
      StoreService.listStores().then(function(branches) {
        Contact.retrieveContactInfo().then(function(userInfo) {
            //more code here crossing user and stores data
        });  
      });
    });

下面让我们来尝试如何用angular提供的$provide创建一个依赖的实现，以及利用jasmine帮助我们fake方法的返回值：

代码如下，有详细注释帮助你去理解这段代码：

    describe("Store Controller", function() {
      var $controller, Contact, StoreService, createController, scope;

      beforeEach(function() {
        module('myApp.store');

        // Provide will help us create fake implementations for our dependencies
        module(function($provide) {

          // Fake StoreService Implementation returning a promise
          $provide.value('StoreService', {
            listStores: function() {
              return { 
                then: function(callback) {return callback([{ some: "thing", hoursInfo: {isOpen: true}}]);}
              };
            },
            chooseStore: function() { return null;}
          });

          // Fake Contact Implementation return an empty object 
          $provide.value('Contact', {
            retrieveContactInfo: function() {
              return {
                then: function(callback) { return callback({});}
              };
            }
          });

          return null;
        });
      });

      beforeEach(function() {

        // When Angular Injects the StoreService and Contact dependencies, 
        // it will use the implementation we provided above
        inject(function($controller, $rootScope, _StoreService_, _Contact_) {
          scope = $rootScope.$new();
          StoreService = _StoreService_;
          Contact = _Contact_;
          createController = function(params) {
            return $controller("StoresCtrl", {
              $scope: scope,
              $stateParams: params || {}
            });
          };
        });
      });

      it("should call the store service to retrieve the store list", function() {
        var user = { address: {street: 1}};

        // Jasmine spy over the listStores service. 
        // Since we provided a fake response already we can just call through. 
        spyOn(StoreService, 'listStores').and.callThrough();

        // Jasmine spy also allows to call Fake implementations via the callFake function 
        // or we can return our own response via 'and.returnValue
        // Here we can override the response we previously defined and return a promise with a user object
        spyOn(Contact, 'retrieveContactInfo').and.callFake(function() {
          return {
            then: function(callback) { return callback(user); }
          };
        });

        createController();
        // Since we setup a spy we can now expect that spied function to have been called 
        // or to have been called with certain parameters..etc
        expect(StoreService.listStores).toHaveBeenCalled();
      });
    });

原文地址:Testing Promises with Jasmine – Provide and Spy