test(avalonia): headless tests for rendering, change events, overlays and theme

.github/workflows/ci.yml

@@ -85,3 +85,7 @@ jobs:
 
     - name: Build Avalonia Demo
       run: dotnet build examples/Avalonia.Demo/AvaloniaDemo.csproj --configuration Release
+
+    # Renders every component and drives them with mouse and keyboard, headless (no display needed)
+    - name: Run Avalonia headless tests
+      run: dotnet test tests/ShellUI.Native.Avalonia.Tests/ShellUI.Native.Avalonia.Tests.csproj --configuration Release

ShellUI.Native.slnx

@@ -18,6 +18,7 @@
     <Project Path="src/ShellUI.Native.Templates/ShellUI.Native.Templates.csproj" />
   </Folder>
   <Folder Name="/tests/">
+    <Project Path="tests/ShellUI.Native.Avalonia.Tests/ShellUI.Native.Avalonia.Tests.csproj" />
     <Project Path="tests/ShellUI.Native.Tests/ShellUI.Native.Tests.csproj" />
   </Folder>
 </Solution>

examples/Avalonia.Demo/Components/UI/Shell.cs

@@ -135,7 +135,9 @@ public static class ShellTheme
     public const double RadiusMd = 6;
     public const double RadiusLg = 8;
 
-    private static bool _initialized;
+    // The app the palettes were published to. A new Application (e.g. one per headless test)
+    // gets them too.
+    private static Application? _initialized;
 
     // Raised when a palette is published or the theme variant changes, for anything resources
     // can't reach (e.g. a BoxShadow).
@@ -161,10 +163,9 @@ public static Color Get(ShellToken token, double opacity)
 
     public static void EnsureInitialized()
     {
-        if (_initialized) return;
         var app = Application.Current;
-        if (app is null) return;
-        _initialized = true;
+        if (app is null || ReferenceEquals(app, _initialized)) return;
+        _initialized = app;
         app.ActualThemeVariantChanged += (_, _) => ThemeChanged?.Invoke(null, EventArgs.Empty);
         Apply();
     }

src/ShellUI.Native.Templates/Templates/ShellTemplate.cs

@@ -1209,7 +1209,9 @@ public static class ShellTheme
     public const double RadiusMd = 6;
     public const double RadiusLg = 8;
 
-    private static bool _initialized;
+    // The app the palettes were published to. A new Application (e.g. one per headless test)
+    // gets them too.
+    private static Application? _initialized;
 
     // Raised when a palette is published or the theme variant changes, for anything resources
     // can't reach (e.g. a BoxShadow).
@@ -1235,10 +1237,9 @@ public static Color Get(ShellToken token, double opacity)
 
     public static void EnsureInitialized()
     {
-        if (_initialized) return;
         var app = Application.Current;
-        if (app is null) return;
-        _initialized = true;
+        if (app is null || ReferenceEquals(app, _initialized)) return;
+        _initialized = app;
         app.ActualThemeVariantChanged += (_, _) => ThemeChanged?.Invoke(null, EventArgs.Empty);
         Apply();
     }

tests/ShellUI.Native.Avalonia.Tests/ChangeEventTests.cs

@@ -0,0 +1,223 @@
+using System.Linq;
+using Avalonia;
+using Avalonia.Automation;
+using Avalonia.Controls;
+using Avalonia.Headless.XUnit;
+using Avalonia.Input;
+using Avalonia.Layout;
+using Avalonia.VisualTree;
+using AvaloniaDemo.Components.UI;
+using Xunit;
+using Switch = AvaloniaDemo.Components.UI.Switch;
+using Slider = AvaloniaDemo.Components.UI.Slider;
+
+namespace ShellUI.Native.Avalonia.Tests;
+
+// Change events report user input only: values set from code stay silent, a click or a key raises
+// the event once.
+public class ChangeEventTests
+{
+    [AvaloniaFact]
+    public void Switch_reports_clicks_and_keys_not_code()
+    {
+        var sw = new Switch { Label = "Wi-Fi" };
+        var window = Ui.Show(sw);
+        var raised = 0;
+        sw.Toggled += (_, _) => raised++;
+
+        sw.IsToggled = true;
+        Assert.Equal(0, raised);
+
+        Ui.Click(window, sw);
+        Assert.Equal(1, raised);
+        Assert.False(sw.IsToggled);
+
+        sw.Focus();
+        Ui.Press(window, Key.Space);
+        Assert.Equal(2, raised);
+        Assert.True(sw.IsToggled);
+    }
+
+    [AvaloniaFact]
+    public void Checkbox_reports_clicks_not_code()
+    {
+        var cb = new Checkbox { Label = "Accept" };
+        var window = Ui.Show(cb);
+        var raised = 0;
+        cb.CheckedChanged += (_, _) => raised++;
+
+        cb.IsChecked = true;
+        Assert.Equal(0, raised);
+        Ui.Click(window, cb);
+        Assert.Equal(1, raised);
+        Assert.False(cb.IsChecked);
+    }
+
+    [AvaloniaFact]
+    public void Toggle_reports_clicks_not_code()
+    {
+        var toggle = new Toggle { Text = "Bold" };
+        var window = Ui.Show(toggle);
+        var raised = 0;
+        toggle.PressedChanged += (_, _) => raised++;
+
+        toggle.IsPressed = true;
+        Assert.Equal(0, raised);
+        Ui.Click(window, toggle);
+        Assert.Equal(1, raised);
+    }
+
+    [AvaloniaFact]
+    public void Slider_reports_drags_and_keys_not_code_or_new_limits()
+    {
+        var slider = new Slider { Width = 300, HorizontalAlignment = HorizontalAlignment.Left };
+        var window = Ui.Show(slider);
+        var raised = 0;
+        slider.ValueChanged += (_, _) => raised++;
+
+        slider.Value = 70;
+        slider.Maximum = 60; // coerces Value to 60
+        Assert.Equal(0, raised);
+
+        var left = slider.TranslatePoint(new Point(10, slider.Bounds.Height / 2), window)!.Value;
+        Ui.ClickAt(window, left);
+        Assert.Equal(1, raised);
+        Assert.True(slider.Value < 10);
+
+        slider.Focus();
+        Ui.Press(window, Key.Right);
+        Assert.Equal(2, raised);
+    }
+
+    [AvaloniaFact]
+    public void Tabs_report_trigger_clicks_and_arrow_keys_not_code()
+    {
+        var a = new TabsTrigger { Value = "a", Text = "Account" };
+        var b = new TabsTrigger { Value = "b", Text = "Password" };
+        var list = new TabsList();
+        list.Items.Add(a);
+        list.Items.Add(b);
+        var tabs = new Tabs { Value = "a", Children = { list } };
+        var window = Ui.Show(tabs);
+        var raised = 0;
+        tabs.ValueChanged += (_, _) => raised++;
+
+        tabs.Value = "b";
+        Assert.Equal(0, raised);
+
+        Ui.Click(window, a);
+        Assert.Equal(1, raised);
+        Assert.Equal("a", tabs.Value);
+
+        a.Focus();
+        Ui.Press(window, Key.Right);
+        Assert.Equal(2, raised);
+        Assert.Equal("b", tabs.Value);
+    }
+
+    [AvaloniaFact]
+    public void Pagination_reports_page_clicks_not_code()
+    {
+        var pagination = new Pagination { TotalPages = 20, Page = 5 };
+        var window = Ui.Show(pagination);
+        var raised = 0;
+        pagination.PageChanged += (_, _) => raised++;
+
+        pagination.Page = 3;
+        Assert.Equal(0, raised);
+        Ui.Settle(); // the page items are rebuilt
+
+        var page4 = pagination.GetVisualDescendants().OfType<Border>().First(b => AutomationProperties.GetName(b) == "Go to page 4");
+        Ui.Click(window, page4);
+        Assert.Equal(1, raised);
+        Assert.Equal(4, pagination.Page);
+    }
+
+    [AvaloniaFact]
+    public void Accordion_reports_trigger_clicks_not_code()
+    {
+        var accordion = new Accordion { Value = "a" };
+        foreach (var value in new[] { "a", "b" })
+        {
+            var item = new AccordionItem { Value = value };
+            item.Items.Add(new AccordionTrigger { Text = value });
+            item.Items.Add(new AccordionContent { Child = new TextBlock { Text = value } });
+            accordion.Children.Add(item);
+        }
+        var window = Ui.Show(accordion);
+        var toggled = 0;
+        var itemOpened = 0;
+        accordion.ItemToggled += (_, _) => toggled++;
+        foreach (var item in accordion.FindDescendantsOfType<AccordionItem>())
+            item.OpenChanged += (_, _) => itemOpened++;
+
+        accordion.Value = "b";
+        Assert.Equal(0, toggled);
+        Assert.Equal(0, itemOpened);
+
+        // Single mode: opening "a" closes "b", and each change is reported.
+        Ui.Click(window, accordion.FindDescendantsOfType<AccordionTrigger>().First());
+        Assert.Equal(2, toggled);
+        Assert.Equal(2, itemOpened);
+        Assert.True(accordion.IsOpen("a"));
+    }
+
+    [AvaloniaFact]
+    public void Collapsible_reports_trigger_clicks_not_code()
+    {
+        var trigger = new CollapsibleTrigger { Child = new TextBlock { Text = "Show more" } };
+        var collapsible = new Collapsible { Children = { trigger, new CollapsibleContent { Child = new TextBlock { Text = "More" } } } };
+        var window = Ui.Show(collapsible);
+        var raised = 0;
+        collapsible.OpenChanged += (_, _) => raised++;
+
+        collapsible.Open = true;
+        collapsible.Toggle();
+        Assert.Equal(0, raised);
+
+        Ui.Click(window, trigger);
+        Assert.Equal(1, raised);
+        Assert.True(collapsible.Open);
+    }
+
+    [AvaloniaFact]
+    public void RadioGroup_reports_item_clicks_not_code()
+    {
+        var first = new RadioGroupItem { Value = "a", Text = "Default" };
+        var second = new RadioGroupItem { Value = "b", Text = "Compact" };
+        var group = new RadioGroup { Value = "a", Children = { first, second } };
+        var window = Ui.Show(group);
+        var raised = 0;
+        group.ValueChanged += (_, _) => raised++;
+
+        group.Value = "b";
+        group.SetValue("a");
+        Assert.Equal(0, raised);
+
+        Ui.Click(window, second);
+        Assert.Equal(1, raised);
+        Assert.Equal("b", group.Value);
+    }
+
+    [AvaloniaFact]
+    public void Select_reports_picked_items_not_code()
+    {
+        var select = new Select { Width = 240, ItemsSource = new[] { "Kenya", "Norway", "Zimbabwe" } };
+        var window = Ui.Show(select);
+        var raised = 0;
+        select.SelectedIndexChanged += (_, _) => raised++;
+
+        select.SelectedIndex = 1;
+        Assert.Equal(0, raised);
+
+        Ui.Click(window, select);
+        Assert.True(select.IsOpen);
+        Ui.Wait(250); // the list fades and scales in
+        var zimbabwe = window.GetVisualDescendants().OfType<TextBlock>()
+            .First(t => t.Text == "Zimbabwe" && t.IsEffectivelyVisible && !Ui.IsWithin(t, select));
+        Ui.Click(window, zimbabwe);
+        Assert.Equal(1, raised);
+        Assert.Equal(2, select.SelectedIndex);
+        Assert.False(select.IsOpen);
+    }
+}

tests/ShellUI.Native.Avalonia.Tests/ComponentSmokeTests.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Avalonia.Controls;
+using Avalonia.Headless;
+using Avalonia.Headless.XUnit;
+using Avalonia.Styling;
+using AvaloniaDemo.Components.UI;
+using Xunit;
+
+namespace ShellUI.Native.Avalonia.Tests;
+
+// Every component can be created, laid out and drawn on its own, in both themes.
+public class ComponentSmokeTests
+{
+    public static IEnumerable<object[]> Components() =>
+        typeof(ShellTheme).Assembly.GetTypes()
+            .Where(t => t.Namespace == typeof(ShellTheme).Namespace && t.IsPublic && !t.IsAbstract
+                        && typeof(Control).IsAssignableFrom(t) && t.GetConstructor(Type.EmptyTypes) != null)
+            .OrderBy(t => t.Name)
+            .Select(t => new object[] { t.Name });
+
+    [AvaloniaTheory]
+    [MemberData(nameof(Components))]
+    public void Renders_in_light_and_dark(string typeName)
+    {
+        var type = typeof(ShellTheme).Assembly.GetTypes().Single(t => t.Name == typeName && t.Namespace == typeof(ShellTheme).Namespace);
+        foreach (var theme in new[] { ThemeVariant.Light, ThemeVariant.Dark })
+        {
+            var control = (Control)Activator.CreateInstance(type)!;
+            var window = Ui.Show(control, theme);
+            Assert.NotNull(window.CaptureRenderedFrame());
+            window.Close();
+        }
+    }
+}