How to configure angular with a provider that needs async initialization? - javascript

I have a serviceProvider that needs some async init. I want my controllers to access this service only if the init is finished.
angular.module("myModule").provider("AsyncInit", {
myThing: {},
init: function(options) {
doSomeAsyncStuff(options).success(function(newThing) {
myThing = newThing;
});
},
$get: function() {
return {
theThing: myThing
}
}
});
//Initialisation of myModule
angular.module(myModule)
.config(function(AsyncInitProvider) {
AsyncInitProvider.init(options);
})
if I access AsyncInit.theThing in a controller it is not initialized at first but is later. This seems logical to me.
Is it possible to wait until the service is fully initialized?

If you really need to start the async call in the configuration process of your provider than you could use $interval.
this.$get = function($q, $interval) {
var deferred = $q.defer();
var handler = $interval(function() {
if (myThingHasBeenLoaded) {
$interval.cancel(handler);
deferred.resolve(myThingsValue);
}
}, 100);
return {
getMyThing: function() {
return deferred.promise();
}
};
}
// In your controller:
myThingService.getMyThing().then(function(myThing) { console.log(myThing); } );
I use this to load the Google experiments API and it works great. The interval will check all 100ms if your thing has been loaded successfully and then resolves the promise. The obvious catch here is that it only resolve every 100ms regardless of if your thing loads in 1ms. I would strongly suggest just to use a simple promise instead IF you don't have to make the async call in the configuration step:
angular.module("myModule").provider("AsyncInit", function () {
this.options = {};
this.init = function(options) {
this.options = options;
};
this.$get = function($q) {
var deferred = $q.defer();
var self = this;
return {
getMyThing: function() {
doSomeAsyncStuff(self.options)
.success(function(newThing) {
deferred.resolve(newThing);
})
.failure(function(errors) {
deferred.reject(errors);
});
return deferred.promise();
}
};
};
});
The code in your controller would be the same as in the example above.

Related

How to test function wrapped in a promis

My ctrl is like this:
(function() {
'use strict';
angular
.module('App')
.controller('DeviceStatesCtrl', DeviceStatesCtrl);
function DeviceStatesCtrl( $rootScope, $scope, $translate,DeviceStatesService) {
var vm = this;
DeviceStatesService.getObject().then(function(response){
vm.init(response);
});
vm.init= function(response){
$translate(['table.title']).then(function(translate){
some stuff here
}));
}
}})();
My jasmine test is like this:
describe('app module', function() {
//var controller = null;
var $controller, $translate,$compile,createController,DeviceStatesService,$translate, scope;
var mockInit= sth;
beforeEach(function () {
module('App');
});
// Provide will help us create fake implementations for our dependencies, do not useful
module(function($provide) {
// Fake StoreService Implementation returning a promise
//nothing works :(
$provide.value('DeviceStatesService', {
getStatesObject: function() {
return {
then: function(callback) {
return callback([{ some: "thing", hoursInfo: {isOpen: true}}]);
}
};
}
});
});
return null;
});
beforeEach(inject(function($controller,$rootScope, _$translate_, _DeviceStatesService_) {
scope = $rootScope.$new();
//for 'controller as' syntax
$controller('DeviceStatesCtrl as deviceStat', {
$scope: scope
});
createController = function(params) {
return $controller("DeviceStatesCtrl as deviceStat", {
$scope: scope,
$stateParams: params || {}
});
};
}));
describe("Unit:Device States controller", function() {
//test init function
it("init function get called correctly", function() {
//spyOn(DeviceStatesService, 'getStatesObject').and.callThrough();
//createController();
//expect(DeviceStatesService.getStatesObject).toHaveBeenCalled();
expect(scope.deviceStat.init).toBeDefined();
//in init, all things are warpped in the $translate
//spyOn(scope.deviceStat, 'init');
scope.deviceStat.init(mockInit);
scope.deviceStat.setChart('All');
//expect(scope.deviceStat.totalNum).toEqual(22);
});
});
});
My question is how to test the init function and the stuff in it? The init function is in a promise, which I do not know how to call it. As my code scope.deviceStat.init(mockInit), it do not work. Another question is in the $translate promise, how to pass parameter in it?
You use the done function, which is a parameter passed to the spec via the jasmine function it.. Example..
describe("My Test set", function() {
it("My Test", function(done) {
doAsync().then(function(result) {
done();
}).catch(function(err) {
fail();
}
}
}
Hope this helps.

AngularJS : testing a factory that returns a promise, while mocking a service that uses $http

I've got a service that has the following method (among others), which returns an $http promise
function sessionService($http, serviceRoot) {
return {
getAvailableDates: function () {
return $http.get(serviceRoot + '/session/available_dates');
}
};
};
angular.module('app').service('sessionService', ['$http', 'serviceRoot', sessionService]);
And then another factory that kinda wraps it and caches/adds data to localStorage. This returns a regular promise
angular.module('app')
.factory('AvailableDates', AvailableDates);
AvailableDates.$inject = ['sessionService', '$window', '$q'];
function AvailableDates(sessionService, $window, $q) {
var availableDates = [];
return {
getAvailableDates: getAvailableDates
};
function getAvailableDates() {
var deferred = $q.defer();
var fromStorage = JSON.parse($window.sessionStorage.getItem('validDates'));
if (availableDates.length > 0) {
deferred.resolve(availableDates);
} else if (fromStorage !== null) {
deferred.resolve(fromStorage);
} else {
sessionService.getAvailableDates()
.success(function (result) {
availableDates = result;
$window.sessionStorage.setItem('validDates', JSON.stringify(availableDates));
deferred.resolve(availableDates);
});
}
return deferred.promise;
}
}
This all works fine. My problem is I can't figure out how to test this thing while mocking the sessionService. I've read all the related stackoverflow questions, and tried all kinds of different things, to no avail.
Here's what my test currently looks like:
describe('testing AvailableDates factory', function () {
var mock, service, rootScope, spy, window, sessionStorageSpy, $q;
var dates = [ "2014-09-27", "2014-09-20", "2014-09-13", "2014-09-06", "2014-08-30" ];
var result;
beforeEach(module('app'));
beforeEach(function() {
return angular.mock.inject(function (_sessionService_, _AvailableDates_, _$rootScope_, _$window_, _$q_) {
mock = _sessionService_;
service = _AvailableDates_;
rootScope = _$rootScope_;
window = _$window_;
$q = _$q_;
});
});
beforeEach(inject(function () {
// my service under test calls this service method
spy = spyOn(mock, 'getAvailableDates').and.callFake(function () {
return {
success: function () {
return [ "2014-09-27", "2014-09-20", "2014-09-13", "2014-09-06", "2014-08-30" ];
},
error: function() {
return "error";
}
};
});
spyOn(window.sessionStorage, "getItem").and.callThrough();
}));
beforeEach(function() {
service.getAvailableDates().then(function(data) {
result = data;
// use done() here??
});
});
it('first call to fetch available dates hits sessionService and returns dates from the service', function () {
rootScope.$apply(); // ??
console.log(result); // this is printing undefined
expect(spy).toHaveBeenCalled(); // this passes
expect(window.sessionStorage.getItem).toHaveBeenCalled(); // this passes
});
});
I've tried various things but can't figure out how to test the result of the AvailableDates.getAvailableDates() call. When I use done(), I get the error:
Timeout - Async callback was not invoked withing timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL (I've tried overriding this value, no luck).
If I take out the done(), and just call rootScope.$apply() after the .then is called, I get an undefined value as my result.
What am I doing wrong?
I see more issues in your example.
The main problem is the success definition in the mock. Success is a function, which has a function as a parameter - callback. Callback is called when data is received - data is passed as the first argument.
return {
success: function (callback) {
callback(dates);
}
};
Simplified working example is here http://plnkr.co/edit/Tj2TZDWPkzjYhsuSM0u3?p=preview
In this example, mock is passed to the provider with the module function (from ngMock) - you can pass the object with a key (service name) and value (implementation). That implementation will be used for injection.
module({
sessionService:sessionServiceMock
});
I think test logic should be in one function (test), split it into beforeEach and test is not a good solution. Test is my example; it's more readable and has clearly separated parts - arrange, act, assert.
inject(function (AvailableDates) {
AvailableDates.getAvailableDates().then(function(data) {
expect(data).toEqual(dates);
done();
});
rootScope.$apply(); // promises are resolved/dispatched only on next $digest cycle
expect(sessionServiceMock.getAvailableDates).toHaveBeenCalled();
expect(window.sessionStorage.getItem).toHaveBeenCalled();
});

AngularJS how to set variable in $http success function of dependency provider

I'm newbie in angularjs and I'm trying to create new provider. This is my code:
myApp.provider('$Data', function() {
this.URL = 'http://maps.googleapis.com/maps/api/geocode/json?address=Singapore, SG, Singapore, 153 Bukit Batok Street 1&sensor=true';
this.$get = $get;
$get.$inject = ['$http', '$q'];
function $get($http, $q) {
var that = this;
return {
isConnected: function() {
var bIsConnected = 'Default';
$http({method: 'GET', url:that.URL}).then(function (data) {
bIsConnected = 'Yes';
alert('Run this code!');
}, function (data) {
bIsConnected = 'No';
});
return bIsConnected;
}
}
}
});
Jsfiddle demo:
http://jsfiddle.net/0udm9/9dPsb/6/
After I run $Data.isConnected(), the result is always 'Default' although browser show the alert box. I think it's from success function is not of $get. And I have to use provider, not service or factory for this case. Can I do anything to fix this issue?
Thanks,
You have to use promise in your code.
DEMO
Provider:
isConnected: function() {
var deferred = $q.defer();
$http.get(that.url).then(function(res) {
deferred.resolve('Yes');
console.log('example:success', res);
}, function(err) {
deferred.resolve('No');
console.log('example:error', err);
});
return deferred.promise;
}
Controller:
$Data.isConnected().then(function(data) {
$scope.data = data;
});
// UPD
You must use objects if you need to use return values with async code.
DEMO
// UPD 2
FRESH DEMO LINK

Test a controller with success() and error ()

I'm trying to work out the best way to unit test success and error callbacks in controllers. I am able to mock out service methods, as long as the controller only uses the default $q functions such as 'then' (see the example below). I'm having an issue when the controller responds to a 'success' or 'error' promise. (Sorry if my terminology is not correct).
Here is an example controller \ service
var myControllers = angular.module('myControllers');
myControllers.controller('SimpleController', ['$scope', 'myService',
function ($scope, myService) {
var id = 1;
$scope.loadData = function () {
myService.get(id).then(function (response) {
$scope.data = response.data;
});
};
$scope.loadData2 = function () {
myService.get(id).success(function (response) {
$scope.data = response.data;
}).error(function(response) {
$scope.error = 'ERROR';
});
};
}]);
cocoApp.service('myService', [
'$http', function($http) {
function get(id) {
return $http.get('/api/' + id);
}
}
]);
I have the following test
'use strict';
describe('SimpleControllerTests', function () {
var scope;
var controller;
var getResponse = { data: 'this is a mocked response' };
beforeEach(angular.mock.module('myApp'));
beforeEach(angular.mock.inject(function($q, $controller, $rootScope, $routeParams){
scope = $rootScope;
var myServiceMock = {
get: function() {}
};
// setup a promise for the get
var getDeferred = $q.defer();
getDeferred.resolve(getResponse);
spyOn(myServiceMock, 'get').andReturn(getDeferred.promise);
controller = $controller('SimpleController', { $scope: scope, myService: myServiceMock });
}));
it('this tests works', function() {
scope.loadData();
expect(scope.data).toEqual(getResponse.data);
});
it('this doesnt work', function () {
scope.loadData2();
expect(scope.data).toEqual(getResponse.data);
});
});
The first test passes and the second fails with the error "TypeError: Object doesn't support property or method 'success'". I get that in this instance that getDeferred.promise
does not have a success function. Okay here is the question, what is a nice way to write this test so that I can test the 'success', 'error' & 'then' conditions of a mocked service ?
I'm starting to think that I should avoid the use of success() and error() in my controllers...
EDIT
So after thinking about this some more, and thanks to the detailed answer below, I've come to the conclusion that the handling the success and error callbacks in the controller is bad. As HackedByChinese mentions below success\error is syntactic sugar that is added by $http. So, in actual fact, by trying to handle success \ error I am letting $http concerns leak into my controller, which is exactly what I was trying to avoid by wrapping the $http calls in a service. The approach I'm going to take is to change the controller not to use success \ error:
myControllers.controller('SimpleController', ['$scope', 'myService',
function ($scope, myService) {
var id = 1;
$scope.loadData = function () {
myService.get(id).then(function (response) {
$scope.data = response.data;
}, function (response) {
$scope.error = 'ERROR';
});
};
}]);
This way I can test the error \ success conditions by calling resolve() and reject() on the deferred object:
'use strict';
describe('SimpleControllerTests', function () {
var scope;
var controller;
var getResponse = { data: 'this is a mocked response' };
var getDeferred;
var myServiceMock;
//mock Application to allow us to inject our own dependencies
beforeEach(angular.mock.module('myApp'));
//mock the controller for the same reason and include $rootScope and $controller
beforeEach(angular.mock.inject(function($q, $controller, $rootScope, $routeParams) {
scope = $rootScope;
myServiceMock = {
get: function() {}
};
// setup a promise for the get
getDeferred = $q.defer();
spyOn(myServiceMock, 'get').andReturn(getDeferred.promise);
controller = $controller('SimpleController', { $scope: scope, myService: myServiceMock });
}));
it('should set some data on the scope when successful', function () {
getDeferred.resolve(getResponse);
scope.loadData();
scope.$apply();
expect(myServiceMock.get).toHaveBeenCalled();
expect(scope.data).toEqual(getResponse.data);
});
it('should do something else when unsuccessful', function () {
getDeferred.reject(getResponse);
scope.loadData();
scope.$apply();
expect(myServiceMock.get).toHaveBeenCalled();
expect(scope.error).toEqual('ERROR');
});
});
As someone had mentioned in a deleted answer, success and error are syntactic sugar added by $http so they aren't there when you create your own promise. You have two options:
1 - Don't mock the service and use $httpBackend to setup expectations and flush
The idea is to let your myService act like it normally would without knowing it's being tested. $httpBackend will let you set up expectations and responses, and flush them so you can complete your tests synchronously. $http won't be any wiser and the promise it returns will look and function like a real one. This option is good if you have simple tests with few HTTP expectations.
'use strict';
describe('SimpleControllerTests', function () {
var scope;
var expectedResponse = { name: 'this is a mocked response' };
var $httpBackend, $controller;
beforeEach(module('myApp'));
beforeEach(inject(function(_$rootScope_, _$controller_, _$httpBackend_){
// the underscores are a convention ng understands, just helps us differentiate parameters from variables
$controller = _$controller_;
$httpBackend = _$httpBackend_;
scope = _$rootScope_;
}));
// makes sure all expected requests are made by the time the test ends
afterEach(function() {
$httpBackend.verifyNoOutstandingExpectation();
$httpBackend.verifyNoOutstandingRequest();
});
describe('should load data successfully', function() {
beforeEach(function() {
$httpBackend.expectGET('/api/1').response(expectedResponse);
$controller('SimpleController', { $scope: scope });
// causes the http requests which will be issued by myService to be completed synchronously, and thus will process the fake response we defined above with the expectGET
$httpBackend.flush();
});
it('using loadData()', function() {
scope.loadData();
expect(scope.data).toEqual(expectedResponse);
});
it('using loadData2()', function () {
scope.loadData2();
expect(scope.data).toEqual(expectedResponse);
});
});
describe('should fail to load data', function() {
beforeEach(function() {
$httpBackend.expectGET('/api/1').response(500); // return 500 - Server Error
$controller('SimpleController', { $scope: scope });
$httpBackend.flush();
});
it('using loadData()', function() {
scope.loadData();
expect(scope.error).toEqual('ERROR');
});
it('using loadData2()', function () {
scope.loadData2();
expect(scope.error).toEqual('ERROR');
});
});
});
2 - Return a fully-mocked promise
If the thing you're testing has complicated dependencies and all the set-up is a headache, you may still want to mock the services and the calls themselves as you have attempted. The difference is that you'll want to fully mock promise. The downside of this can be creating all the possible mock promises, however you could make that easier by creating your own function for creating these objects.
The reason this works is because we pretend that it resolves by invoking the handlers provided by success, error, or then immediately, causing it to complete synchronously.
'use strict';
describe('SimpleControllerTests', function () {
var scope;
var expectedResponse = { name: 'this is a mocked response' };
var $controller, _mockMyService, _mockPromise = null;
beforeEach(module('myApp'));
beforeEach(inject(function(_$rootScope_, _$controller_){
$controller = _$controller_;
scope = _$rootScope_;
_mockMyService = {
get: function() {
return _mockPromise;
}
};
}));
describe('should load data successfully', function() {
beforeEach(function() {
_mockPromise = {
then: function(successFn) {
successFn(expectedResponse);
},
success: function(fn) {
fn(expectedResponse);
}
};
$controller('SimpleController', { $scope: scope, myService: _mockMyService });
});
it('using loadData()', function() {
scope.loadData();
expect(scope.data).toEqual(expectedResponse);
});
it('using loadData2()', function () {
scope.loadData2();
expect(scope.data).toEqual(expectedResponse);
});
});
describe('should fail to load data', function() {
beforeEach(function() {
_mockPromise = {
then: function(successFn, errorFn) {
errorFn();
},
error: function(fn) {
fn();
}
};
$controller('SimpleController', { $scope: scope, myService: _mockMyService });
});
it('using loadData()', function() {
scope.loadData();
expect(scope.error).toEqual("ERROR");
});
it('using loadData2()', function () {
scope.loadData2();
expect(scope.error).toEqual("ERROR");
});
});
});
I rarely go for option 2, even in big applications.
For what it's worth, your loadData and loadData2 http handlers have an error. They reference response.data but the handlers will be called with the parsed response data directly, not the response object (so it should be data instead of response.data).
Don't mix concerns!
Using $httpBackend inside a controller is a bad Idea since you are mixing concerns inside your Test. Whether you retrieve data from an Endpoint or not is not a concern of the Controller, is a concern of the DataService you are calling.
You can see this more clearly if you change the Endpoint Url inside the service you will then have to modify both tests: the service Test and the Controller Test.
Also as previously mentioned, the use of success and error are syntactic sugar and we should stick to the use of then and catch. But in reality you may find yourself in the need of testing "legacy" code. So for that I'm using this function:
function generatePromiseMock(resolve, reject) {
var promise;
if(resolve) {
promise = q.when({data: resolve});
} else if (reject){
promise = q.reject({data: reject});
} else {
throw new Error('You need to provide an argument');
}
promise.success = function(fn){
return q.when(fn(resolve));
};
promise.error = function(fn) {
return q.when(fn(reject));
};
return promise;
}
By calling this function you will get a true promise that respond to then and catch methods when you need to and will also work for the success or error callbacks. Note that the success and error returns a promise itself so it will work with chained then methods.
(NOTE: On the 4th and 6th line the function returns resolve and reject values inside the data property of an object. This is to mock the Behavior of $http since it returns the data, http Status etc.)
Yes, do not use $httpbackend in your controller, because we don't need to make real requests, you just need to make sure that one unit is doing it's job exactly as expected, have a look on this simple controller tests, it's easy to understand
/**
* #description Tests for adminEmployeeCtrl controller
*/
(function () {
"use strict";
describe('Controller: adminEmployeeCtrl ', function () {
/* jshint -W109 */
var $q, $scope, $controller;
var empService;
var errorResponse = 'Not found';
var employeesResponse = [
{id:1,name:'mohammed' },
{id:2,name:'ramadan' }
];
beforeEach(module(
'loadRequiredModules'
));
beforeEach(inject(function (_$q_,
_$controller_,
_$rootScope_,
_empService_) {
$q = _$q_;
$controller = _$controller_;
$scope = _$rootScope_.$new();
empService = _empService_;
}));
function successSpies(){
spyOn(empService, 'findEmployee').and.callFake(function () {
var deferred = $q.defer();
deferred.resolve(employeesResponse);
return deferred.promise;
// shortcut can be one line
// return $q.resolve(employeesResponse);
});
}
function rejectedSpies(){
spyOn(empService, 'findEmployee').and.callFake(function () {
var deferred = $q.defer();
deferred.reject(errorResponse);
return deferred.promise;
// shortcut can be one line
// return $q.reject(errorResponse);
});
}
function initController(){
$controller('adminEmployeeCtrl', {
$scope: $scope,
empService: empService
});
}
describe('Success controller initialization', function(){
beforeEach(function(){
successSpies();
initController();
});
it('should findData by calling findEmployee',function(){
$scope.findData();
// calling $apply to resolve deferred promises we made in the spies
$scope.$apply();
expect($scope.loadingEmployee).toEqual(false);
expect($scope.allEmployees).toEqual(employeesResponse);
});
});
describe('handle controller initialization errors', function(){
beforeEach(function(){
rejectedSpies();
initController();
});
it('should handle error when calling findEmployee', function(){
$scope.findData();
$scope.$apply();
// your error expectations
});
});
});
}());

Accessing factory defined in another module in angularjs

Can we call the factory functions defined in one module from another module? If so, how?
Let's say my first module is defined in moduleOne.js file as:
var myModule = angular.module('MyServiceModuleOne', []);
myModule.factory('notify', function () {
return {
sampleFun: function () {
// some code to call sampleFunTwo()
},
};
});
And my second module in moduleTwo.js as:
var myModuleTwo = angular.module('MyServiceModuleTwo', []);
myModuleTwo.factory('notifytwo', function () {
return {
sampleFunTwo: function () {
// code
},
};
});
How to call sampleFunTwo() from sampleFun()?
Thanks.
You need to inject MyServiceModuleTwo into MyServiceModule:
var myModuleTwo= angular.module('MyServiceModuleTwo',[]);
var myModule= angular.module('MyServiceModuleOne', ['MyServiceModuleTwo']);
Then inject notifytwo into notify:
myModule.factory('notify', function(notifytwo) {
return {
sampleFun: function() {
notifytwo.sampleFunTwo();
}
};
});
myModuleTwo.factory('notifytwo', function() {
return {
sampleFunTwo: function() {
alert('From notify two');
}
};
});
And the code on plunker

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