Fix AutomationProperties.Name binding errors for HintAssist.Hint (#3946)

* Initial plan

* Add ObjectToStringConverter and apply to AutomationProperties.Name bindings

Co-authored-by: Keboo <[email protected]>

* Add unit tests for ObjectToStringConverter

Co-authored-by: Keboo <[email protected]>

* Rename ObjectToStringConverter to AutomationPropertiesNameConverter and move to Internal namespace

Co-authored-by: Keboo <[email protected]>

* Adds internal converters XAML namespace

Registers the 'convertersInternal' XML namespace in the DatePicker, NumericUpDown, and TimePicker theme dictionaries.

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: Keboo <[email protected]>
Co-authored-by: Kevin Bost <[email protected]>

Author: Copilot

src/MaterialDesignThemes.Wpf/Converters/Internal/AutomationPropertiesNameConverter.cs

@@ -0,0 +1,21 @@
+using System.Globalization;
+using System.Windows.Data;
+
+namespace MaterialDesignThemes.Wpf.Converters.Internal;
+
+public class AutomationPropertiesNameConverter : IValueConverter
+{
+    public static readonly AutomationPropertiesNameConverter Instance = new();
+
+    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    {
+        if (value is string stringValue)
+        {
+            return stringValue;
+        }
+        return string.Empty;
+    }
+
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+        => throw new NotImplementedException();
+}

src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.AutoSuggestBox.xaml

@@ -23,7 +23,7 @@
       <converters:OutlinedStyleActiveBorderMarginCompensationConverter x:Key="OutlinedStyleActiveBorderMarginCompensationConverter" />
       <converters:ElevationRadiusConverter x:Key="ElevationRadiusConverter" Multiplier="-1" />
     </Style.Resources>
-    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}}" />
+    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}, Converter={x:Static convertersInternal:AutomationPropertiesNameConverter.Instance}}" />
     <Setter Property="DropDownBackground" Value="{DynamicResource MaterialDesign.Brush.Card.Background}" />
     <Setter Property="DropDownElevation" Value="Dp2" />
     <Setter Property="Template">

src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.ComboBox.xaml

@@ -884,7 +884,7 @@
   </ControlTemplate>
 
   <Style x:Key="MaterialDesignComboBox" TargetType="{x:Type ComboBox}">
-    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}}" />
+    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}, Converter={x:Static convertersInternal:AutomationPropertiesNameConverter.Instance}}" />
     <Setter Property="Background" Value="Transparent" />
     <Setter Property="BorderBrush" Value="{DynamicResource MaterialDesign.Brush.ComboBox.Border}" />
     <Setter Property="BorderThickness" Value="0,0,0,1" />

src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.DatePicker.xaml

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:converters="clr-namespace:MaterialDesignThemes.Wpf.Converters"
+                    xmlns:convertersInternal="clr-namespace:MaterialDesignThemes.Wpf.Converters.Internal"
                     xmlns:internal="clr-namespace:MaterialDesignThemes.Wpf.Internal"
                     xmlns:wpf="clr-namespace:MaterialDesignThemes.Wpf">
   <ResourceDictionary.MergedDictionaries>
@@ -19,7 +20,7 @@
     <Style.Resources>
       <Style x:Key="NestedTextBoxStyle" TargetType="{x:Type DatePickerTextBox}" BasedOn="{StaticResource MaterialDesignTextBox}" />
     </Style.Resources>
-    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}}" />
+    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}, Converter={x:Static convertersInternal:AutomationPropertiesNameConverter.Instance}}" />
     <Setter Property="BorderBrush" Value="{DynamicResource MaterialDesign.Brush.ForegroundLight}" />
     <Setter Property="BorderThickness" Value="0,0,0,1" />
     <Setter Property="CalendarStyle" Value="{StaticResource MaterialDesignDatePickerCalendarPortrait}" />

src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.NumericUpDown.xaml

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:converters="clr-namespace:MaterialDesignThemes.Wpf.Converters"
+                    xmlns:convertersInternal="clr-namespace:MaterialDesignThemes.Wpf.Converters.Internal"
                     xmlns:internal="clr-namespace:MaterialDesignThemes.Wpf.Internal"
                     xmlns:wpf="clr-namespace:MaterialDesignThemes.Wpf">
   <ResourceDictionary.MergedDictionaries>
@@ -33,7 +34,7 @@
              TargetType="{x:Type ButtonBase}"
              BasedOn="{StaticResource MaterialDesignNumericUpDownButtonsStyle}" />
     </Style.Resources>
-    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}}" />
+    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}, Converter={x:Static convertersInternal:AutomationPropertiesNameConverter.Instance}}" />
     <Setter Property="BorderBrush" Value="{DynamicResource MaterialDesign.Brush.ForegroundLight}" />
     <Setter Property="BorderThickness" Value="0,0,0,1" />
     <Setter Property="DecreaseContent" Value="{StaticResource ContentDecrease}" />

src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.PasswordBox.xaml

@@ -51,7 +51,7 @@
       </Style>
     </Style.Resources>
     <Setter Property="AllowDrop" Value="true" />
-    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}}" />
+    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}, Converter={x:Static convertersInternal:AutomationPropertiesNameConverter.Instance}}" />
     <Setter Property="Background" Value="Transparent" />
     <Setter Property="BorderBrush" Value="{DynamicResource MaterialDesign.Brush.ForegroundLight}" />
     <Setter Property="BorderThickness" Value="0,0,0,1" />
@@ -609,7 +609,7 @@
       </Style>
     </Style.Resources>
     <Setter Property="AllowDrop" Value="true" />
-    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}}" />
+    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}, Converter={x:Static convertersInternal:AutomationPropertiesNameConverter.Instance}}" />
     <Setter Property="Background" Value="Transparent" />
     <Setter Property="BorderBrush" Value="{DynamicResource MaterialDesign.Brush.ForegroundLight}" />
     <Setter Property="BorderThickness" Value="0,0,0,1" />

src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.TextBox.xaml

@@ -53,7 +53,7 @@
       <convertersInternal:TextBoxHorizontalScrollBarWidthConverter x:Key="TextBoxHorizontalScrollBarWidthConverter" />
     </Style.Resources>
 
-    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}}" />
+    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}, Converter={x:Static convertersInternal:AutomationPropertiesNameConverter.Instance}}" />
     <Setter Property="AllowDrop" Value="true" />
     <Setter Property="Background" Value="Transparent" />
     <Setter Property="BorderBrush" Value="{DynamicResource MaterialDesign.Brush.TextBox.Border}" />

src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.TimePicker.xaml

@@ -1,6 +1,7 @@
 <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:converters="clr-namespace:MaterialDesignThemes.Wpf.Converters"
+                    xmlns:convertersInternal="clr-namespace:MaterialDesignThemes.Wpf.Converters.Internal"
                     xmlns:internal="clr-namespace:MaterialDesignThemes.Wpf.Internal"
                     xmlns:wpf="clr-namespace:MaterialDesignThemes.Wpf">
   <ResourceDictionary.MergedDictionaries>
@@ -11,7 +12,7 @@
     <Style.Resources>
       <Style x:Key="NestedTextBoxStyle" TargetType="wpf:TimePickerTextBox" BasedOn="{StaticResource MaterialDesignTextBox}" />
     </Style.Resources>
-    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}}" />
+    <Setter Property="AutomationProperties.Name" Value="{Binding Path=(wpf:HintAssist.Hint), RelativeSource={RelativeSource Self}, Converter={x:Static convertersInternal:AutomationPropertiesNameConverter.Instance}}" />
     <Setter Property="BorderBrush" Value="{DynamicResource MaterialDesign.Brush.ForegroundLight}" />
     <Setter Property="BorderThickness" Value="0,0,0,1" />
     <Setter Property="ClockHostContentControlStyle">

tests/MaterialDesignThemes.Wpf.Tests/Converters/AutomationPropertiesNameConverterTests.cs

@@ -0,0 +1,54 @@
+using System.Globalization;
+using MaterialDesignThemes.Wpf.Converters.Internal;
+using TUnit.Core;
+using TUnit.Assertions;
+using TUnit.Assertions.Extensions;
+using System.Threading.Tasks;
+
+namespace MaterialDesignThemes.Wpf.Tests.Converters;
+
+public sealed class AutomationPropertiesNameConverterTests
+{
+    [Test]
+    public async Task Convert_StringValue_ReturnsOriginalString()
+    {
+        var converter = AutomationPropertiesNameConverter.Instance;
+        string input = "Test String";
+        
+        var result = converter.Convert(input, typeof(string), null, CultureInfo.InvariantCulture);
+        
+        await Assert.That(result).IsEqualTo(input);
+    }
+
+    [Test]
+    public async Task Convert_NullValue_ReturnsEmptyString()
+    {
+        var converter = AutomationPropertiesNameConverter.Instance;
+        
+        var result = converter.Convert(null, typeof(string), null, CultureInfo.InvariantCulture);
+        
+        await Assert.That(result).IsEqualTo(string.Empty);
+    }
+
+    [Test]
+    public async Task Convert_NonStringValue_ReturnsEmptyString()
+    {
+        var converter = AutomationPropertiesNameConverter.Instance;
+        int input = 42;
+        
+        var result = converter.Convert(input, typeof(string), null, CultureInfo.InvariantCulture);
+        
+        await Assert.That(result).IsEqualTo(string.Empty);
+    }
+
+    [Test]
+    public async Task Convert_EmptyString_ReturnsEmptyString()
+    {
+        var converter = AutomationPropertiesNameConverter.Instance;
+        string input = string.Empty;
+        
+        var result = converter.Convert(input, typeof(string), null, CultureInfo.InvariantCulture);
+        
+        await Assert.That(result).IsEqualTo(string.Empty);
+    }
+}