我正在为getNextPage()函数编写单元测试。
我设置了测试:Expect(this.anotherService.resources).toEqual(3);
我收到错误消息:运行测试时,预期undefined等于3。
我记录了anotherService.resources,它在控制台中返回了3。
不知道为什么它不起作用。
测试
describe('Test for someController', function() {
beforeEach(function() {
module('someApp');
return inject(function($injector) {
var $controller;
var $q = $injector.get('$q');
this.rootScope = $injector.get('$rootScope');
$controller = $injector.get('$controller');
this.state = $injector.get('$state');
this.stateParams = {
id: 1,
}
this.location = $injector.get('$location')
this.timeout = $injector.get('$timeout')
this.upload = $injector.get('$upload')
this.someService = {
getItemList: function(res) {
var deferred = $q.defer();
deferred.resolve({
data: {
totalRows: 2,
rows: 3,
}
});
return deferred.promise;
},
pages: jasmine.createSpy(),
memberIds: 1,
currEng: []
};
this.anotherService = {
resources: {}
};
this.scope = this.rootScope.$new();
this.controller = $controller('someController', {
'$scope': this.scope,
'$rootScope': this.rootScope,
'$state': this.state,
'$stateParams': this.stateParams,
'$location': this.location,
'$timeout': this.timeout,
'$upload': this.upload,
'someService': this.someService,
});
this.scope.$digest();
});
});
it('should be defined', function() {
expect(this.controller).toBeDefined();
expect(this.scope.ss).toEqual(this.someService);
});
it('should run the getNextPage function', function() {
this.scope.getNextPage();
this.scope.$digest();
console.log(this.anotherService.resources); // this is showing as Object {} in terminal
expect(this.anotherService.resources).toEqual(3);
});
码:
someapp.controller('someController', resource);
resource.$inject = ['$scope', '$state', '$stateParams', '$location','$timeout','$upload', 'someService', 'anotherService'];
function resource($scope, $state, $stateParams,$location,$timeout, $upload, someService, anotherService) {
$scope.fileReaderSupported = window.FileReader != null && (window.FileAPI == null || FileAPI.html5 != false);
$scope.ss = EsomeService;
$scope.as = anotherService;
$scope.getNextPage = getNextPage;
function getNextPage(options){
var o = options || {selected:1};
var start = (o.selected-1)*10 || 0;
someService.currPage = o.selected;
someService.getItemList($stateParams.id,'F', start).then(function (res){
anotherService.resources = res.data.rows;
console.log(anotherService.resources) // this shows LOG: 3 in terminal
someService.numResults = res.data.totalRows;
someService.pageNumbers = someService.pages(res.data.totalRows,10);
})
}
});
最佳答案
在测试中,this.anotherService.resources
的值仍为{}
,因为在测试运行之后,以下then
回调中的代码是异步执行的:
someService.getItemList($stateParams.id,'F', start).then(function (res){
anotherService.resources = res.data.rows;
console.log(anotherService.resources)
someService.numResults = res.data.totalRows;
someService.pageNumbers = someService.pages(res.data.totalRows,10);
})
尽管您在
getItemList
中同步解决了诺言getItemList: function(res) {
var deferred = $q.defer();
deferred.resolve({
data: {
totalRows: 2,
rows: 3,
}
});
return deferred.promise;
},
...实际上,当您调用
then
时,它实际上不会立即在promise上调用deferred.resolve
函数。当您想到它时,这也没有意义,因为必须先将诺言返回给调用者,然后调用者才能将then
调用附加到它。取而代之的是,它异步调用then
回调,即在所有当前执行的代码以空的调用栈结束后。这包括您的测试代码!如Angular documentation中所述:then(successCallback, errorCallback, notifyCallback)
–无论何时,或者将要解决或拒绝承诺,只要结果可用,then
都会异步调用成功或错误回调之一。以及testing example in the same documentation中:
// Simulate resolving of promise
deferred.resolve(123);
// Note that the 'then' function does not get called synchronously.
// This is because we want the promise API to always be async, whether or not
// it got called synchronously or asynchronously.
如何测试异步代码
首先,您可以让
getNextPage
返回承诺-与getItemList
返回的承诺相同:function getNextPage(options){
var o = options || {selected:1};
var start = (o.selected-1)*10 || 0;
someService.currPage = o.selected;
// store the promise in a variable
var prom = someService.getItemList($stateParams.id,'F', start);
prom.then(function (res){
anotherService.resources = res.data.rows;
console.log(anotherService.resources) // this shows LOG: 3 in terminal
someService.numResults = res.data.totalRows;
someService.pageNumbers = someService.pages(res.data.totalRows,10);
});
return prom; // return that promise
}
然后可以在
then
上使用getNextPage()
,它将与附加的任何其他then
回调顺序执行,因此在上述代码的then
回调之后。然后,可以使用Jasmine的
done
告诉Jasmine测试是异步的,以及何时完成:// The presence of the `done` parameter indicates to Jasmine that
// the test is asynchronous
it('should run the getNextPage function', function(done) {
this.scope.getNextPage().then(function () {
this.scope.$digest();
console.log(this.anotherService.resources);
expect(this.anotherService.resources).toEqual(3);
done(); // indicate to Jasmine that the asynchronous test has completed
});
});
关于javascript - 功能单元测试,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/37686511/