Sergey Barskiy's Blog

In my last post I am going to cover the last two topics I set out to address.  The first topic is UI testing.  What unit test frameworks lack sometime is the actually UI testing.  What I mean by that is for example, click on a button, then see what happens.  In case of Silverlight, Silverlight framework itself has a number of helper classes to help us achieve this goal.  For example, ButtonAutomationPeer class allows us to drive button actions from within unit tests.  Also, Microsoft Silverlight unit testing framework allows developers to insert UI components onto unit testing surface.  Let me illustrate both concepts via an example.  Here is my code for such unit test”

[TestMethod]
[Asynchronous]
[Description("Asynch Get Companies in UI")]
[Tag("Asynch")]
public void TestUIGetCompanies()
{
 
    var companyVM = new CompanyModule.ViewModels.CompanyListViewModel(
        new Microsoft.Practices.Composite.Events.EventAggregator());
    CompanyListView companyV = new CompanyListView();
    companyV.DataContext = companyVM;
    TestPanel.Children.Add(companyV);
    ButtonAutomationPeer buttonPeer = 
        new ButtonAutomationPeer(companyV.FindName("GetCompaniesButton") as Button);
    DataGrid grid = companyV.FindName("CompanyGrid") as DataGrid;
    IInvokeProvider buttonInvoker = (IInvokeProvider)buttonPeer;
 
    IGridProvider gridPeer = new DataGridAutomationPeer(grid);
 
    EnqueueCallback(() => buttonInvoker.Invoke());
    EnqueueConditional(() => { return companyVM.CompanyList != null; });
    EnqueueCallback(
        () => Assert.IsTrue(companyVM.CompanyList.Count() > 0, "Should have data"),
        () => Assert.IsTrue(grid.Columns.Count == 3, "Should have 3 columns"),
        () => Assert.IsTrue(gridPeer.RowCount > 0, "Should have rows"));
    EnqueueTestComplete();
}

Let’s trace down what is going on in this test.  First of all, I am creating view model class.  Since I do not have a bootstrapper, I manually create EventAggregator myself.  Next, I am create a view to put my view model into.  I create view, then put my view model into the data context of my view.  Nest important step is to add my view to unit te3swt harness.  This is accomplished by adding my view to test panel.  My screenshot below illustrates where test panel is in terms of test runnier UI.  I added hand cursor to illustrate the test panel referred to in UI below as “Test Stage.”  As I run the unit tests, I will actually see my view there in the test stage.  Just like I added the view, I can remove it from test stage.

Next I am setting up code to invoke a button.  I am creating new instance of ButtonAutomationPeer class.  Of course, I need to find a button to attach the automation peer to, and I am using FindName method to find an i9nstance of my button.  To use this functionality I had to name my button.  Then, I am setting up an automation peer for my grid as well.  In general, most user input controls in Silverlight framework have matching automation objects.  In my case, I am testing the results of my button invocation directly against the grid, making sure that the grid has correct number of rows and columns.  I can also combine this type of testing with mocking,  Here is the unit test for this case:

[TestMethod]
[Asynchronous]
[Description("Asynch Get Companies in UI With Mocking")]
[Tag("Asynch")]
public void TestUIGetCompaniesWithMock()
{
    var companyVM = new Mock<ICompanyListViewModel>();
    companyVM.SetupGet(testVM => testVM.CompanyList).
        Returns(new ObservableCollection<Company>(new[] {
        new Company(){
            CompanyID = Guid.NewGuid(), DateAdded = DateTime.Now, CompanyName = "some random company"},
        new Company(){ 
            CompanyID = Guid.NewGuid(), DateAdded = DateTime.Now.AddDays(-1), CompanyName = "another company"}}));
    companyVM.SetupGet(testVM => testVM.GetCompaniesCommand).
        Returns(new DelegateCommand<object>((o) =>
        companyVM.Raise(vm => 
            vm.PropertyChanged += null, new System.ComponentModel.PropertyChangedEventArgs("CompanyList"))));
 
 
    CompanyListView companyV = new CompanyListView();
    companyV.DataContext = companyVM.Object;
    TestPanel.Children.Add(companyV);
    ButtonAutomationPeer buttonPeer = new ButtonAutomationPeer(companyV.FindName("GetCompaniesButton") as Button);
    DataGrid grid = companyV.FindName("CompanyGrid") as DataGrid;
    IInvokeProvider buttonInvoker = (IInvokeProvider)buttonPeer;
 
    IGridProvider gridPeer = new DataGridAutomationPeer(grid);
 
    EnqueueCallback(() => buttonInvoker.Invoke());
            
    EnqueueCallback(
        () => Assert.IsTrue(companyVM.Object.CompanyList.Count() > 0, "Should have data"),
        () => Assert.AreEqual(3, grid.Columns.Count, "Should have 3 columns"),
        () => Assert.AreEqual(2, gridPeer.RowCount, "Should have rows"));
    EnqueueTestComplete();
}

In the case above I am mocking property changed event by invoking it when a button is clicked, causing UI to re-bind.  The rest of testing code is very similar to actual invocation of server side code.

The last topic I would like to cover is StatLight framework.  You can take a closer look at the framework here.  This framework allows developers to invoke unit tests written with Microsoft unit testing framework for Silverlight from a command line and also read in results of such runs.  Once you download and unzip the DLLs into a folder, you will need to do one more thing – Unblock those DLLs in the properties of each file in Windows explorer.  Also, if you want to test server side code using StatLight, you will need to convert your web site to use local IIS inste4ad of Cassini (Visual Studio built-in IIS Server).  You will also need to put clientaccesspolicy.xml into the root of your IIS in order to avoid cross domain exceptions.  Using the StatLight framework is very simple.  Simply call StatLight.exe and pass XAP file on command line that contains your unit tests.  Here is a screenshot of what it looks like:

As you can see, your –x parameter is the only one you have to specify to test.  You will also see that unit test is launched at the same time.  Now, to test results you have to add one more parameter – r.  Here is what that command would look like:

Once you run this, you will end up with out.txt in the specified folder.  Here is the content of this file:

The last parameter I want to mention is ability to limit test run by tag attribute I covered in an earlier post.  To user this feature, you have to add –t command line attribute like so:  Here is what this command line look like:

You can download complete solution here.

Thanks.

In this post I will explore ability to mock various Silverlight classes in order to enable mocking in your unit tests.  There is a variety of mocking frameworks available, but I will pick one for my testing – Moq.  You can download the framework here,  Once this is done, I need to add some references to my Silverlight unit test project.

Moq requires three assemblies available in the folder where Moq is installed:

If we are mocking view model or another object relying on Prism, we also need to add Prism references

Now we are ready to mock!

Let’s start by doing something simple.  I will mock my view model.  The only property I really want to test is my model property, which in my case exposes list of companies.  TO do so, I just need to setup property getter that contains my model.  The getter will be called when first accessed.  Here is what we have:

[TestMethod]
[Tag("Mocking")]
[Description("VM Mocking")]
public void TestMocking()
{
    var vm = new Mock<ICompanyListViewModel>();
    vm.SetupGet(testVM => testVM.CompanyList).
        Returns(new ObservableCollection<Company>(new[] {
            new Company()
                { CompanyID = Guid.NewGuid(), DateAdded = DateTime.Now, CompanyName = "some random company"},
            new Company()
                { CompanyID = Guid.NewGuid(), DateAdded = DateTime.Now.AddDays(-1), CompanyName = "another company"}}));
    Assert.AreEqual(2, vm.Object.CompanyList.Count, "Mocking failed");
 
}

I am only mocking view model in this case.  With Moq framework, as it is the case with most mocking frameworks, you are required to have interfaces in order to mock.  In case of RIA Services, this is an issue because client side classes are sealed and do not implement interfaces.  If you are using your own WCF service with custom classes, you can avoid this small issue.  You can also mock events as well.  This is how I would mock property changed event in my view model:

companyVM.SetupGet(testVM => testVM.GetCompaniesCommand).Returns(new DelegateCommand<object>((o) =>
    companyVM.Raise(vm => vm.PropertyChanged += null, new System.ComponentModel.PropertyChangedEventArgs("CompanyList"))));

As you can see, mocking is pretty easy concept, and the web page for Moq has quick start guide to help you get started.  Feel free to use a different mocking framework as well.  In the next post I will show how to unit test user interface using Silverlight unit testing framework.

Thanks

In this post I will describe how to create asynchronous unit tests for Silverlight applications.  First of all, I’d like to point out that any communication with a server component in Silverlight must be asynchronous.  Reason being is that if communication was synchronous and the remote service was not responding, browser which host Silverlight application would lock up.  As you can see, asynchronous communication with a RIA Services WCF service is very important in our case. 

Let’s take a look on how to write a test that would assert that we can successfully get a list of companies from the server.  To do so, we must first take a look on how to write such a test.  This can be accomplished using asynchronous constructs available in Silverlight unit testing framework.  First of all, we have to change inheritance for our test class.  When you create a new test class, it does not inherit from any class, and we have to change this first of all.  Here is what old test class declaration look like:

[TestClass]
public class Tests

Here is what we are going to change it to:

[TestClass]
public class Tests : Microsoft.Silverlight.Testing.SilverlightTest

Now we must decorate our test method with appropriate attribute to signal to test running harness that it is about to execute asynchronous test:

[TestMethod]
[Asynchronous]
[Description("Asynch Get Companies")]
[Tag("Asynch")]
public void TestGetCompanies()

Now, let take a deeper look into framework itself to see the key methods that we can use in base class – SilverlightTest.

First one is EnqueueConditional.  This method is designed to let unit test wait until condition specified as an argument to EnqueueConditional is met.  It is very useful when you want to wait until a method call to the service is completed.  Here is how I would use this method:

        [TestMethod]
        [Asynchronous]
        [Description("Asynch Get Companies")]
        [Tag("Asynch")]
        public void TestGetCompanies()
        {
            bool isLoaded = false;
            Exception error = null;
            IEnumerable<Company> results = null;
            CompanyDomainContext context = new CompanyDomainContext(new Uri(@"http://localhost:4988/SilverlightTestingDemo-Web-CompanyDomainService.svc", UriKind.Absolute));
            var query = context.GetCompaniesQuery();
 
            context.Load<Company>(query, (result) =>
            {
                isLoaded = true;
                results = result.Entities;
                error = result.Error;
            }, null);
            EnqueueConditional(() => isLoaded);

What I am doing above is declaring a Boolean variable isLoaded that would signal to the framework to continue the test once data has been loaded.  I am setting this variable to true in the lambda expression callback that is called one server method’s execution is completed – (result)=> expression.

Next interesting method is EnqueueCallback.  This method simply declares multiple or in Action delegates that will be executed one they are popped off execution stack when harness processes test method calls.  What I mean is that the harness will execute all Action delegates that EnqueueCallback declares when it proceeds with running a test method once condition that  EnqueueConditional declares is met. If there are no such calls in the method body and there are no calls to EnqueueDelay that would also pause execution, then EnqueueCallback has no meaning, and asynchronous test essentially becomes synchronous.  Here is what we have so far:

        [TestMethod]
        [Asynchronous]
        [Description("Asynch Get Companies")]
        [Tag("Asynch")]
        public void TestGetCompanies()
        {
            
            bool isLoaded = false;
            Exception error = null;
            IEnumerable<Company> results = null;
            CompanyDomainContext context = new CompanyDomainContext(new Uri(@"http://localhost:4988/SilverlightTestingDemo-Web-CompanyDomainService.svc", UriKind.Absolute));
            var query = context.GetCompaniesQuery();
 
            context.Load<Company>(query, (result) =>
            {
                isLoaded = true;
                results = result.Entities;
                error = result.Error;
            }, null);
            EnqueueConditional(() => isLoaded);
            EnqueueCallback(
                () => Assert.IsTrue(results.Count() > 0, "Should have data"),
                () => Assert.IsNull(error, "Should have no errors"));

The last important method is EnqueueTestComplete.  This method puts Test Completed signal onto the execution stack. This method is typically the very last statement of the test method body.  Here is our final version of the method:

        [TestMethod]
        [Asynchronous]
        [Description("Asynch Get Companies")]
        [Tag("Asynch")]
        public void TestGetCompanies()
        {
            
            bool isLoaded = false;
            Exception error = null;
            IEnumerable<Company> results = null;
            CompanyDomainContext context = new CompanyDomainContext(new Uri(@"http://localhost:4988/SilverlightTestingDemo-Web-CompanyDomainService.svc", UriKind.Absolute));
            var query = context.GetCompaniesQuery();
 
            context.Load<Company>(query, (result) =>
            {
                isLoaded = true;
                results = result.Entities;
                error = result.Error;
            }, null);
            EnqueueConditional(() => isLoaded);
            EnqueueCallback(
                () => Assert.IsTrue(results.Count() > 0, "Should have data"),
                () => Assert.IsNull(error, "Should have no errors"));
            EnqueueTestComplete();
        }

You can download the complete code here.  In the next post I will cover mocking for synchronous and asynchronous unit tests.

Thanks..

I am starting a short series of posts on unit testing of Silverlight applications.  I will be using the following set of technologies. 

• Microsoft Silverlight Unit testing framework that ships with Silverlight tool kit
• Moq – mocking framework that supports Silverlight 4
• StatLight – unit testing automation framework that will allow for unattended / automated running unit tests

I am going to start with a simple Silverlight application that is using RIA services and Prism.  First things first, let’s create unit test project.  Project template will be installed when you install the Silverlight toolkit.  Here is what add project dialog looks like.  The template is located under Silverlight tab

Here are the setting for the next dialog:

Once project is created, a simple test class is also created.  If you ever worked with Microsoft unit testing in Visual Studio, you will find the API quite familiar, including all key classed, attributes and namespaces.  I am going to create a simple synchronous test first, testing my RIA services class to ensure that validation rules are setup properly.  To do so, I first add a reference to my simple Company module to my Silverlight unit test project.  Since I am also testing RIA services classes, I will add two more references: System.ComponentModel.DataAnnotations and System.ServiceModel.DomainServices.Client.dll.  Now with this our of the way, here is what my test class and method look like:

using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Microsoft.Silverlight.Testing;
using System.Collections.ObjectModel;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using SilverlightTestingDemo.Web;
 
namespace SilverlightUnitTest
{
    [TestClass]
    public class Tests
    {
        [TestMethod]
        [Tag("Synch")]
        [Description("Rules")]
        public void TestCompanyRules()
        {
            Company company = new Company();
            company.CompanyName = "test";
            Assert.AreEqual(0, company.ValidationErrors.Count, "Should be valid");
            company.CompanyName = string.Empty;
            Assert.AreEqual(1, company.ValidationErrors.Count, "Should be in valid");
        }
    }
}

Let me go over the attributes I used.  TestClass attribute is what signals to Unit testing framework as to what classes contain unit tests.  TestMethod attribute identifies methods that represent a single unit test.  Tag attribute is used by unit test runner UI to filter out what tests based on attributes will be run.  Description attribute data will be shown in runner UI when unit tests are run. Assert class is used to assert test results.  For example, in my first Assert statement I make sure that Company instance is valid once name is set.

When I run unit tests after setting up unit test application’s web site as start up project, here is what I see.

Test are setup to auto-run by default.  You will see the countdown label, and if you click on count down label, you will have a chance to select specific tests to run.

After tests are run, you will see test run summary in the top left cornet of the screen.  In my case I see that I had total of 1 test, and 2 test has passed.  if a test fails, you will see that in the test run summary.  You can download solution so far here.  In my next post I will cover asynchronous testing in Silverlight application.

Thanks.