Get started with UITest and Xamarin.Forms

UITest can be used with Xamarin.Forms to write UI tests to run in the cloud on hundreds of devices.

Overview

App Center Test allows developers to write automated user interface tests for iOS and Android apps. With some minor tweaks, Xamarin.Forms apps can be tested using Xamarin.UITest, including sharing the same test code. This article introduces specific tips to get Xamarin.UITest working with Xamarin.Forms.

This guide does assume that familiarity with Xamarin.UITest. The following guides are recommended for gaining familiarity with Xamarin.UITest:

• Introduction to App Center Test
• Introduction to UITest for Xamarin.Android
• Introduction to UITest for Xamarin.iOS

Once a UITest project has been added to a Xamarin.Forms solution, the steps for writing and running the tests for a Xamarin.Forms application are the same as for a Xamarin.Android or Xamarin.iOS application.

Requirements

Refer to Xamarin.UITest to confirm your project is ready for automated UI testing.

Adding UITest support to Xamarin.Forms apps

UITest automates the user interface by activating controls on the screen and providing input anywhere a user would normally interact with the application. To enable tests that can press a button or enter text in a box the test code will need a way to identify the controls on the screen.

To enable the UITest code to reference controls, each control needs a unique identifier. In Xamarin.Forms, the recommended way to set this identifier is by using the AutomationId property as shown below:

var b = new Button {
    Text = "Click me",
    AutomationId = "MyButton"
};
var l = new Label {
    Text = "Hello, Xamarin.Forms!",
    AutomationId = "MyLabel"
};

The AutomationId property can also be set in XAML:

<Button x:Name="b" AutomationId="MyButton" Text="Click me"/>
<Label x:Name="l" AutomationId="MyLabel" Text="Hello, Xamarin.Forms!" />

A unique AutomationId should be added to all controls that are required for testing (including buttons, text entries, and labels whose value might need to be queried).

iOS application project

To run tests on iOS, the Xamarin Test Cloud Agent NuGet package must be added to the project. Once it's been added, copy the following code into the AppDelegate.FinishedLaunching method:

#if ENABLE_TEST_CLOUD
// requires Xamarin Test Cloud Agent
Xamarin.Calabash.Start();
#endif

The Calabash assembly uses non-public Apple APIs, which cause apps to be rejected by the App Store. However, the Xamarin.iOS linker will remove the Calabash assembly from the final IPA if it isn't explicitly referenced from code.

The following screenshot shows the ENABLE_TEST_CLOUD compiler variable set for Debug builds:

Android application project

Unlike iOS, Android projects don't need any special startup code.

Writing UITests

For information about writing UITests, see UITest documentation.

Use AutomationId in the Xamarin.Forms UI

Before any UITests can be written, the Xamarin.Forms application user interface must be scriptable. Ensure that all controls in the user interface have a AutomationId so that they can be referenced in test code.

Referring to the AutomationId in UITests

When writing UITests, the AutomationId value is exposed differently on each platform:

• iOS uses the id field.
• Android uses the label field.

To write cross-platform UITests that will find the AutomationId on both iOS and Android, use the Marked test query:

app.Query(c=>c.Marked("MyButton"))

The shorter form app.Query("MyButton") also works.

Adding a UITest project to an existing solution

public override bool FinishedLaunching(UIApplication app, NSDictionary options)
{
    #if ENABLE_TEST_CLOUD
    Xamarin.Calabash.Start();
    #endif

    global::Xamarin.Forms.Forms.Init();

    LoadApplication(new App());

    return base.FinishedLaunching(app, options);
}

After adding Xamarin.UITest to the Xamarin.Forms solution, it's possible to create UITests, run them locally, and submit them to App Center Test.

Summary

Xamarin.Forms applications can be easily tested with Xamarin.UITest using a simple mechanism to expose the AutomationId as a unique view identifier for test automation. Once a UITest project has been added to a Xamarin.Forms solution, the steps for writing and running the tests for a Xamarin.Forms application are the same as for a Xamarin.Android or Xamarin.iOS application.

For information about how to submit tests to App Center Test, see Submitting UITests for Xamarin.Android or Submitting UITests for Xamarin.iOS. For more information about UITest, see App Center Test documentation.

Related links

• NUnit