Add styles during testing

To add styles to elements during testing, call AddTestComponent<StylesApplicator>() to add a StylesApplicator component to the test fixture. The styles are automatically cleaned up at the end of the test.

The following example shows how to add styles using the StylesApplicator:

public class StylesApplicatorExampleClass : UITestFixture
{
    StylesApplicator m_StylesApplicator;

    [OneTimeSetUp]
    public void OneTimeSetUp()
    {
        // Add the test component and keep its reference
        // to add styles to elements later.
        m_StylesApplicator = AddTestComponent<StylesApplicator>();
    }

    [Test]
    public void StylesApplicatorExample()
    {
        Button button = rootVisualElement.Q<Button>("MyButton");

        Assume.That(button.resolvedStyle.backgroundColor,
            Is.Not.EqualTo(Color.red));

        // Add a style to the button.
        m_StylesApplicator.AddStylesToElement(
            button, ".unity-button { background-color: rgb(255, 0, 0); }");
        simulate.FrameUpdate();

        Assert.That(button.resolvedStyle.backgroundColor,
            Is.EqualTo(Color.red));

        // Add a style to the root.
        m_StylesApplicator.AddStylesToRoot(
            "Button:hover { color: rgb(0, 0, 255); }");
        simulate.FrameUpdate();

        Assume.That(button.resolvedStyle.color,
            Is.Not.EqualTo(Color.blue));

        // Mouse over the button to activate the :hover
        // style that was added to the root.
        simulate.MouseMove(button.worldBound.center);
        simulate.FrameUpdate();

        Assert.That(button.resolvedStyle.color,
            Is.EqualTo(Color.blue));
    }

    [SetUp]
    public void SetUp()
    {
        VisualTreeAsset uxml = Resources.Load<VisualTreeAsset>("UITestFrameworkDocSample");
        uxml.CloneTree(rootVisualElement);

        simulate.FrameUpdate();
    }
}

Add styles during testing

Additional resources