Queries on Unit Testing in Xamarin - xamarin

Question

I'm developing cross platform app for Android, Windows Desktop 8.1, WinPhone 8.1, iOS on Xamarin and now added Test projects. I went through multiple resources for UITests but had following queries. It could be helpful if anyone can correct me.
Projects of type Android test, Windows Phone test, iOS test exists. When these are run, these executes as an app in device/emulator. So, how would these test original app running on same device?
If I have two different android project, how can I specify in above test projects which one to test?
I also added UITest project, which is class library project. In this I can mention apk file using following code:
[SetUp]
public void BeforeEachTest()
{
app = ConfigureApp.Android.ApkFile(#"Path\to\apk\com.namespace.apk")
.DeviceSerial("emulator-1234")
.StartApp();
}
How to reference a project to test rather then .apk file, so I could modify project every time I run tests?
How can I combine UITest project and native test projects? Like common portable library is referenced by native projects.
Thanks in advance

Answer 1

Regarding point 4.
At present, running console UnitTests against Xamarin.Forms, i.e testing the ViewModel, Commands, and Navigation in isolation of the UI takes a fair bit of setup. Testing the ViewModels in total isolation of the Xamarin.Forms framework disallows testing across multiple ViewModels.
For instance, testing a login viewmodel in complete isolation where:
user enters username/password
click login button
redirected to the authenticated screen with their data populated
will not work, as that requires a hook on the viewmodel navigation, so the test can authenticate on the Login ViewModel, then navigate and initialise the Authenticated ViewModel.
So I put out a nuget library that allows to simply achieve this, and also provide Bdd using specflow. The test run as nunit test on vs test shell, or any nunit console runners (such as in Build Servers such as Team City).
Example:
public class GeneralSteps : TestStepBase
{
public GeneralSteps(ScenarioContext scenarioContext)
: base(scenarioContext)
{
// you need to instantiate your steps by passing the scenarioContext to the base
}
[Given(#"I am on the main view")]
public void GivenIAmOnTheMainView()
{
Resolver.Instance.Resolve<INavigationService>().PushAsync<MainViewMode>();
Resolver.Instance.Resolve<INavigationService>().CurrentViewModelType.ShouldEqualType<MainViewModel>();
}
[When(#"I click on the button")]
public void WhenIClickOnTheButton()
{
GetCurrentViewModel<MainViewModel>().GetTextCommand.Execute(null);
}
[Then(#"I can see a Label with text ""(.*)""")]
public void ThenICanSeeALabelWithText(string text)
{
GetCurrentViewModel<MainViewModel>().Text.ShouldEqual(text);
}
}
Step by step instructions here
Nuget package here

Answer 2

Not sure I understand this question.
UITest will deploy and run the app in the device/emulator and will then run the tests against that app. For iOS apps being tested it will start the emulator for you. For Android apps being tested you will have to start the emulator yourself. If they are different Android apps then presumably the UITests would be different for each Android app so keeping the UITests as separate project seems reasonable, especially if you are uploading the tests to Xamarin Test Cloud.
Also note that UITest does not support Windows Phone projects currently, so it can only be used to test your Android and iOS project.
With two different Android projects you would either create a UITest project for each Android project or you would need to specify the path to the .apk file in the test, using ConfigureApp.Android.ApkFile () as you have already done in the code example.
If you are using Xamarin Studio you can run the UITests directly in the IDE without having to specify the full path to the .apk file or the iOS .app.
What you would need to do is have the UITest project reference the Android project. However it needs a special type of reference so you will need to use Xamarin Studio to do this. You add this special type of reference from the Unit Tests window, by finding the Test Apps item, selecting Add App Project and then selecting the Android and/or iOS project.
More information is available in the Adding UITest to a solution on Xamarin's developer guide.
Note that you can have a single UITest project test both the iOS and Android apps. Assuming that they are both the same application. However you may need to create Android and iOS specific UI test queries to find UI elements on the screen.
First you should ask yourself if you really need to combine UITests with native test projects. For example the UITests may take a long time to run, so if you have some fast unit tests you may not want to run them all together.
Combining them is possible if the native test projects are essentially NUnit projects. A UITest project is basically a NUnit project. It has a reference to NUnit and is a class library. If your native tests can be run from a NUnit project then you could combine them. However you would not be able to run the native tests in Xamarin's Test Cloud.
If the native test projects do not use NUnit then you cannot combine them with the UITest project.