diff --git a/tests/Fluent.UITests/ControlTests/Data/ExpanderTests.xaml b/tests/Fluent.UITests/ControlTests/Data/ExpanderTests.xaml
new file mode 100644
index 0000000..cd140af
--- /dev/null
+++ b/tests/Fluent.UITests/ControlTests/Data/ExpanderTests.xaml
@@ -0,0 +1,391 @@
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    xmlns:sys="clr-namespace:System;assembly=System.Runtime"
+ xmlns:ut="clr-namespace:Fluent.UITests.TestUtilities">
+    <ResourceDictionary.MergedDictionaries>
+        <ut:TestDictionary Name="Light">
+            <ut:TestDictionary.MergedDictionaries>
+                <ut:TestDictionary Source="/Fluent.UITests;component/ResourceTests/Data/Light.Test.xaml" />
+
+                <ut:TestDictionary Name="Default">
+                    <!-- Expander Control Properties -->
+                    <SolidColorBrush x:Key="Expander_Background" Color="{StaticResource CardBackgroundFillColorDefault}" />
+                    <SolidColorBrush x:Key="Expander_Foreground" Color="{StaticResource TextFillColorPrimary}" />
+                    <SolidColorBrush x:Key="Expander_BorderBrush" Color="{StaticResource CardStrokeColorDefault}" />
+                    <Thickness x:Key="Expander_BorderThickness">1</Thickness>
+                    <Thickness x:Key="Expander_Padding">16,0,0,0</Thickness>
+                    <HorizontalAlignment x:Key="Expander_HorizontalContentAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="Expander_VerticalContentAlignment">Center</VerticalAlignment>
+                    <HorizontalAlignment x:Key="Expander_HorizontalAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="Expander_VerticalAlignment">Center</VerticalAlignment>
+                    <FontWeight x:Key="Expander_FontWeight">Normal</FontWeight>
+
+                    <!-- Toggle button Border Properties -->
+                    <SolidColorBrush x:Key="ToggleButtonBorder_Background" Color="{StaticResource CardBackgroundFillColorDefault}" />
+                    <SolidColorBrush x:Key="ToggleButtonBorder_BorderBrush" Color="{StaticResource CardStrokeColorDefault}" />
+                    <Thickness x:Key="ToggleButtonBorder_BorderThickness">1</Thickness>
+                    <CornerRadius x:Key="ToggleButtonBorder_CornerRadius">4</CornerRadius>
+
+                    <!--Toggle Button properties-->
+                    <Thickness x:Key="ToggleButton_Padding">16,0,0,0</Thickness>
+                    <HorizontalAlignment x:Key="ToggleButton_HorizontalContentAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ToggleButton_VerticalContentAlignment">Center</VerticalAlignment>
+                    <HorizontalAlignment x:Key="ToggleButton_HorizontalAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ToggleButton_VerticalAlignment">Center</VerticalAlignment>
+                    <SolidColorBrush x:Key="ToggleButton_Foreground" Color="{StaticResource TextFillColorPrimary}" />
+                    <SolidColorBrush x:Key="ToggleButton_BorderBrush" Color="{StaticResource CardStrokeColorDefault}" />
+                    <sys:Double x:Key="ToggleButton_FontSize">12</sys:Double>
+                    <FontWeight x:Key="ToggleButton_FontWeight">Normal</FontWeight>
+
+                    <!--toggle button grid properties-->
+                    <SolidColorBrush x:Key="ToggleButtonGrid_Background" Color="{StaticResource ControlFillColorTransparent}" />
+                   
+                    <!--toggle button content presenter-->
+                    <Thickness x:Key="ToggleButtonContentPresenter_Margin">0</Thickness>
+                    <HorizontalAlignment x:Key="ToggleButtonContentPresenter_HorizontalAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ToggleButtonContentPresenter_VerticalAlignment">Center</VerticalAlignment>
+
+                    <!--ChevronGrid properties-->
+                    <VerticalAlignment x:Key="ChevronGrid_VerticalAlignment">Center</VerticalAlignment>
+                    <SolidColorBrush x:Key="ChevronGrid_Background" Color="{StaticResource ControlFillColorTransparent}" />
+                    
+                    <!--textblock properties-->
+                    <sys:Double x:Key="Textblock_FontSize">12</sys:Double>
+                    <SolidColorBrush x:Key="Textblock_Foreground" Color="{StaticResource TextFillColorPrimary}" />
+                    <FontFamily x:Key="Textblock_FontFamily">Segoe Fluent Icons, Segoe MDL2 Assets</FontFamily>
+                    <HorizontalAlignment x:Key="Textblock_HorizontalAlignment">Center</HorizontalAlignment>
+                    <sys:String x:Key="Textblock_Text">&#xE70D;</sys:String>
+
+                    <!--content presenter border-->
+                    <SolidColorBrush x:Key="ContentPresenterBorder_Background" Color="{StaticResource CardBackgroundFillColorSecondary}" />
+                    <SolidColorBrush x:Key="ContentPresenterBorder_BorderBrush" Color="{StaticResource CardStrokeColorDefault}" />
+                    <Thickness x:Key="ContentPresenterBorder_BorderThickness">0</Thickness>
+                    <CornerRadius x:Key="ContentPresenterBorder_CornerRadius">4</CornerRadius>
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Collapsed</Visibility>
+                    
+                    <!-- ContentPresenter Properties -->
+                    <HorizontalAlignment x:Key="ContentPresenter_HorizontalAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ContentPresenter_VerticalAlignment">Center</VerticalAlignment>
+                    <Thickness x:Key="ContentPresenter_Margin">0</Thickness>
+                    
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="ExpandDown">
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Visible</Visibility>
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="ExpandUp">
+                    <CornerRadius x:Key="ToggleButtonBorder_CornerRadius">0,0,4,4</CornerRadius>
+                    <Thickness x:Key="ContentPresenterBorder_BorderThickness">1,1,1,0</Thickness>
+                    <CornerRadius x:Key="ContentPresenterBorder_CornerRadius">4,4,0,0</CornerRadius>
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Visible</Visibility>
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="ExpandLeft">
+                    <CornerRadius x:Key="ToggleButtonBorder_CornerRadius">0,4,4,0</CornerRadius>
+                    <Thickness x:Key="ContentPresenterBorder_BorderThickness">1,1,0,1</Thickness>
+                    <CornerRadius x:Key="ContentPresenterBorder_CornerRadius">4,0,0,4</CornerRadius>
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Visible</Visibility>
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="ExpandRight">
+                    <CornerRadius x:Key="ToggleButtonBorder_CornerRadius">4,0,0,4</CornerRadius>
+                    <Thickness x:Key="ContentPresenterBorder_BorderThickness">0,1,1,1</Thickness>
+                    <CornerRadius x:Key="ContentPresenterBorder_CornerRadius">0,4,4,0</CornerRadius>
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Visible</Visibility>
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="Disabled">
+                    <SolidColorBrush x:Key="ToggleButton_Foreground" Color="{StaticResource TextFillColorDisabled}" />
+                    <SolidColorBrush x:Key="Textblock_Foreground" Color="{StaticResource TextFillColorDisabled}" />
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="CustomBrush">
+                    <SolidColorBrush x:Key="Expander_Background" Color="Aqua" />
+                    <SolidColorBrush x:Key="Expander_Foreground" Color="Maroon" />
+                    <SolidColorBrush x:Key="Expander_BorderBrush" Color="Green" />
+
+                    <SolidColorBrush x:Key="ToggleButtonBorder_Background" Color="Aqua" />
+                    <SolidColorBrush x:Key="ToggleButtonBorder_BorderBrush" Color="Green" />
+                    <SolidColorBrush x:Key="ToggleButton_Foreground" Color="Maroon" />
+                    <!--<SolidColorBrush x:Key="ToggleButton_BorderBrush" Color="Green" />-->
+                    <SolidColorBrush x:Key="Textblock_Foreground" Color="Maroon" />
+
+                    <SolidColorBrush x:Key="ContentPresenterBorder_BorderBrush" Color="Green" />
+                    
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="Custom">
+                    <Thickness x:Key="Expander_BorderThickness">10</Thickness>
+                    <Thickness x:Key="Expander_Padding">12,0,12,0</Thickness>
+                    <HorizontalAlignment x:Key="Expander_HorizontalContentAlignment">Center</HorizontalAlignment>
+                    <VerticalAlignment x:Key="Expander_VerticalContentAlignment">Bottom</VerticalAlignment>
+                    <HorizontalAlignment x:Key="Expander_HorizontalAlignment">Center</HorizontalAlignment>
+                    <VerticalAlignment x:Key="Expander_VerticalAlignment">Bottom</VerticalAlignment>
+                    <FontWeight x:Key="Expander_FontWeight">Bold</FontWeight>
+
+                    <!-- Toggle button Border Properties -->
+                     <Thickness x:Key="ToggleButtonBorder_BorderThickness">10</Thickness>
+
+                    <Thickness x:Key="ToggleButton_Padding">12,0,12,0</Thickness>
+                    <VerticalAlignment x:Key="ToggleButton_VerticalAlignment">Bottom</VerticalAlignment>
+                    <FontWeight x:Key="ToggleButton_FontWeight">Bold</FontWeight>
+
+                    <!--<Thickness x:Key="ContentPresenterBorder_BorderThickness">10</Thickness>-->
+
+                    <HorizontalAlignment x:Key="ContentPresenter_HorizontalAlignment">Center</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ContentPresenter_VerticalAlignment">Bottom</VerticalAlignment>
+                    <Thickness x:Key="ContentPresenter_Margin">12,0,12,0</Thickness>
+                </ut:TestDictionary>
+            </ut:TestDictionary.MergedDictionaries>
+        </ut:TestDictionary>
+        <ut:TestDictionary Name="Dark">
+            <ut:TestDictionary.MergedDictionaries>
+                <ut:TestDictionary Source="/Fluent.UITests;component/ResourceTests/Data/Dark.Test.xaml" />
+
+                <ut:TestDictionary Name="Default">
+                    <!-- Expander Control Properties -->
+                    <SolidColorBrush x:Key="Expander_Background" Color="{StaticResource CardBackgroundFillColorDefault}" />
+                    <SolidColorBrush x:Key="Expander_Foreground" Color="{StaticResource TextFillColorPrimary}" />
+                    <SolidColorBrush x:Key="Expander_BorderBrush" Color="{StaticResource CardStrokeColorDefault}" />
+                    <Thickness x:Key="Expander_BorderThickness">1</Thickness>
+                    <Thickness x:Key="Expander_Padding">16,0,0,0</Thickness>
+                    <HorizontalAlignment x:Key="Expander_HorizontalContentAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="Expander_VerticalContentAlignment">Center</VerticalAlignment>
+                    <HorizontalAlignment x:Key="Expander_HorizontalAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="Expander_VerticalAlignment">Center</VerticalAlignment>
+                    <FontWeight x:Key="Expander_FontWeight">Normal</FontWeight>
+
+                    <!-- Toggle button Border Properties -->
+                    <SolidColorBrush x:Key="ToggleButtonBorder_Background" Color="{StaticResource CardBackgroundFillColorDefault}" />
+                    <SolidColorBrush x:Key="ToggleButtonBorder_BorderBrush" Color="{StaticResource CardStrokeColorDefault}" />
+                    <Thickness x:Key="ToggleButtonBorder_BorderThickness">1</Thickness>
+                    <CornerRadius x:Key="ToggleButtonBorder_CornerRadius">4</CornerRadius>
+
+                    <!--Toggle Button properties-->
+                    <Thickness x:Key="ToggleButton_Padding">16,0,0,0</Thickness>
+                    <HorizontalAlignment x:Key="ToggleButton_HorizontalContentAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ToggleButton_VerticalContentAlignment">Center</VerticalAlignment>
+                    <HorizontalAlignment x:Key="ToggleButton_HorizontalAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ToggleButton_VerticalAlignment">Center</VerticalAlignment>
+                    <SolidColorBrush x:Key="ToggleButton_Foreground" Color="{StaticResource TextFillColorPrimary}" />
+                    <sys:Double x:Key="ToggleButton_FontSize">12</sys:Double>
+                    <FontWeight x:Key="ToggleButton_FontWeight">Normal</FontWeight>
+                    
+                    <!--toggle button grid properties-->
+                    <SolidColorBrush x:Key="ToggleButtonGrid_Background" Color="{StaticResource ControlFillColorTransparent}" />
+
+                    <!--toggle button content presenter-->
+                    <Thickness x:Key="ToggleButtonContentPresenter_Margin">0</Thickness>
+                    <HorizontalAlignment x:Key="ToggleButtonContentPresenter_HorizontalAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ToggleButtonContentPresenter_VerticalAlignment">Center</VerticalAlignment>
+                    <sys:Double x:Key="ToggleButtonContentPresenter_FontSize">12</sys:Double>
+
+                    <!--ChevronGrid properties-->
+                    <VerticalAlignment x:Key="ChevronGrid_VerticalAlignment">Center</VerticalAlignment>
+                    <SolidColorBrush x:Key="ChevronGrid_Background" Color="{StaticResource ControlFillColorTransparent}" />
+
+                    <!--textblock properties-->
+                    <sys:Double x:Key="Textblock_FontSize">12</sys:Double>
+                    <SolidColorBrush x:Key="Textblock_Foreground" Color="{StaticResource TextFillColorPrimary}" />
+                    <FontFamily x:Key="Textblock_FontFamily">Segoe Fluent Icons, Segoe MDL2 Assets</FontFamily>
+                    <HorizontalAlignment x:Key="Textblock_HorizontalAlignment">Center</HorizontalAlignment>
+                    <sys:String x:Key="Textblock_Text">&#xE70D;</sys:String>
+
+                    <!--content presenter border-->
+                    <SolidColorBrush x:Key="ContentPresenterBorder_Background" Color="{StaticResource CardBackgroundFillColorSecondary}" />
+                    <SolidColorBrush x:Key="ContentPresenterBorder_BorderBrush" Color="{StaticResource CardStrokeColorDefault}" />
+                    <Thickness x:Key="ContentPresenterBorder_BorderThickness">0</Thickness>
+                    <CornerRadius x:Key="ContentPresenterBorder_CornerRadius">4</CornerRadius>
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Collapsed</Visibility>
+                    <!-- ContentPresenter Properties -->
+                    <HorizontalAlignment x:Key="ContentPresenter_HorizontalAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ContentPresenter_VerticalAlignment">Center</VerticalAlignment>
+                    <Thickness x:Key="ContentPresenter_Margin">0</Thickness>
+                    
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="ExpandDown">
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Visible</Visibility>
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="ExpandUp">
+                    <CornerRadius x:Key="ToggleButtonBorder_CornerRadius">0,0,4,4</CornerRadius>
+                    <Thickness x:Key="ContentPresenterBorder_BorderThickness">1,1,1,0</Thickness>
+                    <CornerRadius x:Key="ContentPresenterBorder_CornerRadius">4,4,0,0</CornerRadius>
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Visible</Visibility>
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="ExpandLeft">
+                    <CornerRadius x:Key="ToggleButtonBorder_CornerRadius">0,4,4,0</CornerRadius>
+                    <Thickness x:Key="ContentPresenterBorder_BorderThickness">1,1,0,1</Thickness>
+                    <CornerRadius x:Key="ContentPresenterBorder_CornerRadius">4,0,0,4</CornerRadius>
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Visible</Visibility>
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="ExpandRight">
+                    <CornerRadius x:Key="ToggleButtonBorder_CornerRadius">4,0,0,4</CornerRadius>
+                    <Thickness x:Key="ContentPresenterBorder_BorderThickness">0,1,1,1</Thickness>
+                    <CornerRadius x:Key="ContentPresenterBorder_CornerRadius">0,4,4,0</CornerRadius>
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Visible</Visibility>
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="Disabled">
+                    <SolidColorBrush x:Key="ToggleButton_Foreground" Color="{StaticResource TextFillColorDisabled}" />
+                    <SolidColorBrush x:Key="Textblock_Foreground" Color="{StaticResource TextFillColorDisabled}" />
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="CustomBrush">
+                    <SolidColorBrush x:Key="Expander_Background" Color="Aqua" />
+                    <SolidColorBrush x:Key="Expander_Foreground" Color="Maroon" />
+                    <SolidColorBrush x:Key="Expander_BorderBrush" Color="Green" />
+                    
+                    <SolidColorBrush x:Key="ToggleButtonBorder_Background" Color="Aqua" />
+                    <SolidColorBrush x:Key="ToggleButtonBorder_BorderBrush" Color="Green" />
+                    <SolidColorBrush x:Key="ToggleButton_Foreground" Color="Maroon" />
+                    <!--<SolidColorBrush x:Key="ToggleButton_BorderBrush" Color="Green" />-->
+                    <SolidColorBrush x:Key="Textblock_Foreground" Color="Maroon" />
+
+                    <SolidColorBrush x:Key="ContentPresenterBorder_BorderBrush" Color="Green" />
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="Custom">
+                    <Thickness x:Key="Expander_BorderThickness">10</Thickness>
+                    <Thickness x:Key="Expander_Padding">12,0,12,0</Thickness>
+                    <HorizontalAlignment x:Key="Expander_HorizontalContentAlignment">Center</HorizontalAlignment>
+                    <VerticalAlignment x:Key="Expander_VerticalContentAlignment">Bottom</VerticalAlignment>
+                    <HorizontalAlignment x:Key="Expander_HorizontalAlignment">Center</HorizontalAlignment>
+                    <VerticalAlignment x:Key="Expander_VerticalAlignment">Bottom</VerticalAlignment>
+                    <FontWeight x:Key="Expander_FontWeight">Bold</FontWeight>
+
+                    <!-- Toggle button Border Properties -->
+                    <Thickness x:Key="ToggleButtonBorder_BorderThickness">10</Thickness>
+
+                    <Thickness x:Key="ToggleButton_Padding">12,0,12,0</Thickness>
+                    <VerticalAlignment x:Key="ToggleButton_VerticalAlignment">Bottom</VerticalAlignment>
+                    <FontWeight x:Key="ToggleButton_FontWeight">Bold</FontWeight>
+
+                    <Thickness x:Key="ContentPresenterBorder_BorderThickness">10</Thickness>
+
+                    <HorizontalAlignment x:Key="ContentPresenter_HorizontalAlignment">Center</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ContentPresenter_VerticalAlignment">Bottom</VerticalAlignment>
+                    <Thickness x:Key="ContentPresenter_Margin">12,0,12,0</Thickness>
+                </ut:TestDictionary>
+            </ut:TestDictionary.MergedDictionaries>
+        </ut:TestDictionary>
+        <ut:TestDictionary Name="HC">
+            <ut:TestDictionary.MergedDictionaries>
+                <ut:TestDictionary Source="/Fluent.UITests;component/ResourceTests/Data/HC.Test.xaml" />
+
+                <ut:TestDictionary Name="Default">
+                    <!-- Expander Control Properties -->
+                    <SolidColorBrush x:Key="Expander_Background" Color="{StaticResource SystemColorButtonFaceColor}" />
+                    <SolidColorBrush x:Key="Expander_Foreground" Color="{StaticResource SystemColorButtonTextColor}" />
+                    <SolidColorBrush x:Key="Expander_BorderBrush" Color="{StaticResource SystemColorButtonTextColor}" />
+                    <Thickness x:Key="Expander_BorderThickness">1</Thickness>
+                    <Thickness x:Key="Expander_Padding">16,0,0,0</Thickness>
+                    <HorizontalAlignment x:Key="Expander_HorizontalContentAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="Expander_VerticalContentAlignment">Center</VerticalAlignment>
+                    <HorizontalAlignment x:Key="Expander_HorizontalAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="Expander_VerticalAlignment">Center</VerticalAlignment>
+                    <FontWeight x:Key="Expander_FontWeight">Normal</FontWeight>
+
+                    <!-- Toggle button Border Properties -->
+                    <SolidColorBrush x:Key="ToggleButtonBorder_Background" Color="{StaticResource SystemColorButtonFaceColor}" />
+                    <SolidColorBrush x:Key="ToggleButtonBorder_BorderBrush" Color="{StaticResource SystemColorButtonTextColor}" />
+                    <Thickness x:Key="ToggleButtonBorder_BorderThickness">1</Thickness>
+                    <CornerRadius x:Key="ToggleButtonBorder_CornerRadius">4</CornerRadius>
+
+                    <!--Toggle Button properties-->
+                    <Thickness x:Key="ToggleButton_Padding">16,0,0,0</Thickness>
+                    <HorizontalAlignment x:Key="ToggleButton_HorizontalContentAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ToggleButton_VerticalContentAlignment">Center</VerticalAlignment>
+                    <HorizontalAlignment x:Key="ToggleButton_HorizontalAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ToggleButton_VerticalAlignment">Center</VerticalAlignment>
+                    <SolidColorBrush x:Key="ToggleButton_Foreground" Color="{StaticResource SystemColorButtonTextColor}" />
+                    <sys:Double x:Key="ToggleButton_FontSize">12</sys:Double>
+                    <FontWeight x:Key="ToggleButton_FontWeight">Normal</FontWeight>
+
+                    <!--toggle button grid properties-->
+                    <SolidColorBrush x:Key="ToggleButtonGrid_Background" Color="{StaticResource ControlFillColorTransparent}" />
+
+                    <!--toggle button content presenter-->
+                    <Thickness x:Key="ToggleButtonContentPresenter_Margin">0</Thickness>
+                    <HorizontalAlignment x:Key="ToggleButtonContentPresenter_HorizontalAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ToggleButtonContentPresenter_VerticalAlignment">Center</VerticalAlignment>
+                    <sys:Double x:Key="ToggleButtonContentPresenter_FontSize">12</sys:Double>
+
+                    <!--ChevronGrid properties-->
+                    <VerticalAlignment x:Key="ChevronGrid_VerticalAlignment">Center</VerticalAlignment>
+                    <SolidColorBrush x:Key="ChevronGrid_Background" Color="{StaticResource ControlFillColorTransparent}" />
+
+                    <!--textblock properties-->
+                    <sys:Double x:Key="Textblock_FontSize">12</sys:Double>
+                    <SolidColorBrush x:Key="Textblock_Foreground" Color="{StaticResource SystemColorButtonTextColor}" />
+                    <FontFamily x:Key="Textblock_FontFamily">Segoe Fluent Icons, Segoe MDL2 Assets</FontFamily>
+                    <HorizontalAlignment x:Key="Textblock_HorizontalAlignment">Center</HorizontalAlignment>
+                    <sys:String x:Key="Textblock_Text">&#xE70D;</sys:String>
+                    
+                    <!--content presenter border-->
+                    <SolidColorBrush x:Key="ContentPresenterBorder_Background" Color="{StaticResource SystemColorWindowColor}" />
+                    <SolidColorBrush x:Key="ContentPresenterBorder_BorderBrush" Color="{StaticResource SystemColorButtonTextColor}" />
+                    <Thickness x:Key="ContentPresenterBorder_BorderThickness">0</Thickness>
+                    <CornerRadius x:Key="ContentPresenterBorder_CornerRadius">4</CornerRadius>
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Collapsed</Visibility>
+                    <!-- ContentPresenter Properties -->
+
+                    <HorizontalAlignment x:Key="ContentPresenter_HorizontalAlignment">Stretch</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ContentPresenter_VerticalAlignment">Center</VerticalAlignment>
+                    <Thickness x:Key="ContentPresenter_Margin">0</Thickness>
+                    
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="ExpandDown">
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Visible</Visibility>
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="ExpandUp">
+                    <CornerRadius x:Key="ToggleButtonBorder_CornerRadius">0,0,4,4</CornerRadius>
+                    <Thickness x:Key="ContentPresenterBorder_BorderThickness">1,1,1,0</Thickness>
+                    <CornerRadius x:Key="ContentPresenterBorder_CornerRadius">4,4,0,0</CornerRadius>
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Visible</Visibility>
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="ExpandLeft">
+                    <CornerRadius x:Key="ToggleButtonBorder_CornerRadius">0,4,4,0</CornerRadius>
+                    <Thickness x:Key="ContentPresenterBorder_BorderThickness">1,1,0,1</Thickness>
+                    <CornerRadius x:Key="ContentPresenterBorder_CornerRadius">4,0,0,4</CornerRadius>
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Visible</Visibility>
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="ExpandRight">
+                    <CornerRadius x:Key="ToggleButtonBorder_CornerRadius">4,0,0,4</CornerRadius>
+                    <Thickness x:Key="ContentPresenterBorder_BorderThickness">0,1,1,1</Thickness>
+                    <CornerRadius x:Key="ContentPresenterBorder_CornerRadius">0,4,4,0</CornerRadius>
+                    <Visibility x:Key="ContentPresenterBorder_Visibility">Visible</Visibility>
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="Disabled">
+                    <SolidColorBrush x:Key="ToggleButton_Foreground" Color="{StaticResource SystemColorGrayTextColor}" />
+                    <SolidColorBrush x:Key="Textblock_Foreground" Color="{StaticResource SystemColorGrayTextColor}" />           
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="CustomBrush">
+                    <SolidColorBrush x:Key="Expander_Background" Color="Aqua" />
+                    <SolidColorBrush x:Key="Expander_Foreground" Color="Maroon" />
+                    <SolidColorBrush x:Key="Expander_BorderBrush" Color="Green" />
+
+                    <SolidColorBrush x:Key="ToggleButtonBorder_Background" Color="Aqua" />
+                    <SolidColorBrush x:Key="ToggleButtonBorder_BorderBrush" Color="Green" />
+                    <SolidColorBrush x:Key="ToggleButton_Foreground" Color="Maroon" />
+                    <!--<SolidColorBrush x:Key="ToggleButton_BorderBrush" Color="Green" />-->
+                    <SolidColorBrush x:Key="Textblock_Foreground" Color="Maroon" />
+
+                    <SolidColorBrush x:Key="ContentPresenterBorder_BorderBrush" Color="Green" />
+                </ut:TestDictionary>
+                <ut:TestDictionary Name="Custom">
+                    <Thickness x:Key="Expander_BorderThickness">10</Thickness>
+                    <Thickness x:Key="Expander_Padding">12,0,12,0</Thickness>
+                    <HorizontalAlignment x:Key="Expander_HorizontalContentAlignment">Center</HorizontalAlignment>
+                    <VerticalAlignment x:Key="Expander_VerticalContentAlignment">Bottom</VerticalAlignment>
+                    <HorizontalAlignment x:Key="Expander_HorizontalAlignment">Center</HorizontalAlignment>
+                    <VerticalAlignment x:Key="Expander_VerticalAlignment">Bottom</VerticalAlignment>
+                    <FontWeight x:Key="Expander_FontWeight">Bold</FontWeight>
+
+                    <!-- Toggle button Border Properties -->
+                    <Thickness x:Key="ToggleButtonBorder_BorderThickness">10</Thickness>
+
+                    <Thickness x:Key="ToggleButton_Padding">12,0,12,0</Thickness>
+                    <VerticalAlignment x:Key="ToggleButton_VerticalAlignment">Bottom</VerticalAlignment>
+                    <FontWeight x:Key="ToggleButton_FontWeight">Bold</FontWeight>
+
+                    <Thickness x:Key="ContentPresenterBorder_BorderThickness">10</Thickness>
+
+                    <HorizontalAlignment x:Key="ContentPresenter_HorizontalAlignment">Center</HorizontalAlignment>
+                    <VerticalAlignment x:Key="ContentPresenter_VerticalAlignment">Bottom</VerticalAlignment>
+                    <Thickness x:Key="ContentPresenter_Margin">12,0,12,0</Thickness>
+                </ut:TestDictionary>
+            </ut:TestDictionary.MergedDictionaries>
+        </ut:TestDictionary>
+    </ResourceDictionary.MergedDictionaries>
+</ResourceDictionary>
\ No newline at end of file
diff --git a/tests/Fluent.UITests/ControlTests/ExpanderTests.cs b/tests/Fluent.UITests/ControlTests/ExpanderTests.cs
new file mode 100644
index 0000000..74914e5
--- /dev/null
+++ b/tests/Fluent.UITests/ControlTests/ExpanderTests.cs
@@ -0,0 +1,417 @@
+using Fluent.UITests.TestUtilities;
+using FluentAssertions.Execution;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Controls.Primitives;
+using System.Windows.Documents;
+using System.Windows.Media;
+using Xunit.Abstractions;
+
+namespace Fluent.UITests.ControlTests
+{
+    public class ExpanderTests : BaseControlTests
+    {
+        private ITestOutputHelper _outputHelper;
+
+        public ExpanderTests(ITestOutputHelper outputHelper)
+        {
+            _outputHelper = outputHelper;
+            SetUpExpander();
+            TestExpander.Should().NotBeNull();
+        }
+
+        #region Default Tests
+        [WpfTheory]
+        [MemberData(nameof(ColorModes_TestData))]
+        public void Expander_Initialization_Test(ColorMode colorMode)
+        {
+            SetColorMode(TestWindow, colorMode);
+            TestWindow.Show();
+            // TestExpander.IsExpanded = true;
+            ResourceDictionary rd = GetTestDataDictionary(colorMode, "");
+            VerifyControlProperties(TestExpander, rd);
+        }
+
+        [WpfTheory]
+        [MemberData(nameof(ColorModes_TestData))]
+        public void Expander_DownExpansion_Test(ColorMode colorMode)
+        {
+            SetColorMode(TestWindow, colorMode);
+            TestWindow.Show();
+            TestExpander.IsExpanded = true;
+            TestExpander.ExpandDirection = ExpandDirection.Down;
+            ResourceDictionary rd = GetTestDataDictionary(colorMode, "ExpandDown");
+            VerifyControlProperties(TestExpander, rd);
+        }
+
+        [WpfTheory]
+        [MemberData(nameof(ColorModes_TestData))]
+        public void Expander_UpExpansion_Test(ColorMode colorMode)
+        {
+            SetColorMode(TestWindow, colorMode);
+            TestWindow.Show();
+            TestExpander.IsExpanded = true;
+            TestExpander.ExpandDirection = ExpandDirection.Up;
+            ResourceDictionary rd = GetTestDataDictionary(colorMode, "ExpandUp");
+            VerifyControlProperties(TestExpander, rd);
+        }
+
+        [WpfTheory]
+        [MemberData(nameof(ColorModes_TestData))]
+        public void Expander_LeftExpansion_Test(ColorMode colorMode)
+        {
+            SetColorMode(TestWindow, colorMode);
+            TestWindow.Show();
+            TestExpander.IsExpanded = true;
+            TestExpander.ExpandDirection = ExpandDirection.Left;
+            ResourceDictionary rd = GetTestDataDictionary(colorMode, "ExpandLeft");
+            VerifyControlProperties(TestExpander, rd);
+        }
+
+        [WpfTheory]
+        [MemberData(nameof(ColorModes_TestData))]
+        public void Expander_RightExpansion_Test(ColorMode colorMode)
+        {
+            SetColorMode(TestWindow, colorMode);
+            TestWindow.Show();
+            TestExpander.IsExpanded = true;
+            TestExpander.ExpandDirection = ExpandDirection.Right;
+            ResourceDictionary rd = GetTestDataDictionary(colorMode, "ExpandRight");
+            VerifyControlProperties(TestExpander, rd);
+        }
+
+        [WpfTheory]
+        [MemberData(nameof(ColorModes_TestData))]
+        public void Expander_Disabled_Test(ColorMode colorMode)
+        {
+            SetColorMode(TestWindow, colorMode);
+            TestWindow.Show();
+            TestExpander.IsEnabled = false;
+            ResourceDictionary rd = GetTestDataDictionary(colorMode, "Disabled");
+            VerifyControlProperties(TestExpander, rd);
+        }
+
+        #endregion
+
+        #region Custom Test
+        [WpfTheory]
+        [MemberData(nameof(ColorModes_TestData))]
+        public void Expander_CustomSolidColorBrush_Test(ColorMode colorMode)
+        {
+            SetColorMode(TestWindow, colorMode);
+            TestWindow.Show();
+            SetSolidColorBrushProperties();
+            ResourceDictionary rd = GetTestDataDictionary(colorMode, "CustomBrush");
+            VerifyControlProperties(TestExpander, rd);
+        }
+
+        [WpfTheory]
+        [MemberData(nameof(ColorModes_TestData))]
+        public void Expander_Custom_Test(ColorMode colorMode)
+        {
+            SetColorMode(TestWindow, colorMode);
+            TestWindow.Show();
+            SetCustomizedProperties();
+            ResourceDictionary rd = GetTestDataDictionary(colorMode, "Custom");
+            VerifyControlProperties(TestExpander, rd);
+        }
+        #endregion
+        #region Override Methods
+
+        public override List<FrameworkElement> GetStyleParts(Control element)
+        {
+            List<FrameworkElement> templateParts = [element];
+
+            Border? toggleButtonBorder = element.Template.FindName("ToggleButtonBorder", element) as Border;
+            toggleButtonBorder.Should().NotBeNull();
+
+            templateParts.Add(toggleButtonBorder);
+
+            ToggleButton? toggleButton = element.Template.FindName("HeaderSite", element) as ToggleButton;
+            toggleButton.Should().NotBeNull();
+
+            templateParts.Add(toggleButton);
+
+            if (TestExpander.ExpandDirection == ExpandDirection.Down)
+            {
+                Grid? toggleButtonDownGrid = GetChildOfType<Grid>(toggleButton);
+                toggleButtonDownGrid.Should().NotBeNull();
+
+                templateParts.Add(toggleButtonDownGrid);
+
+                ContentPresenter? toggleButtonDownContentPresenter = GetChildOfType<ContentPresenter>(toggleButtonDownGrid);
+                toggleButtonDownContentPresenter.Should().NotBeNull();
+
+                templateParts.Add(toggleButtonDownContentPresenter);
+
+                Grid? ChevronGrid = GetChildOfType<Grid>(toggleButtonDownGrid);
+                ChevronGrid.Should().NotBeNull();
+
+                templateParts.Add(ChevronGrid);
+
+                TextBlock? ControlChevronIcon = GetChildOfType<TextBlock>(ChevronGrid);
+                ControlChevronIcon.Should().NotBeNull();
+
+                templateParts.Add(ControlChevronIcon);
+            }
+            Border? contentPresenterBorder = element.Template.FindName("ContentPresenterBorder", element) as Border;
+            contentPresenterBorder.Should().NotBeNull();
+
+            templateParts.Add(contentPresenterBorder);
+
+            ContentPresenter? contentPresenter = element.Template.FindName("ContentPresenter", element) as ContentPresenter;
+            contentPresenter.Should().NotBeNull();
+
+            templateParts.Add(contentPresenter);
+            return templateParts;
+        }
+        public override void VerifyControlProperties(FrameworkElement element, ResourceDictionary expectedProperties)
+        {
+            if (element is not Expander expander) return;
+
+            List<FrameworkElement> parts = GetStyleParts(expander);
+
+            Expander? part_expander = parts[0] as Expander;
+            Border? part_ToggleButtonBorder = parts[1] as Border;
+            ToggleButton? part_ToggleButton = parts[2] as ToggleButton;
+            Grid? part_ToggleButtonGrid = null;
+            ContentPresenter? part_ToggleButtonContentPresenter = null;
+            Grid? part_ChevronGrid = null;
+            TextBlock? part_ControlChevronIcon = null;
+            Border? part_contentPresenterBorder = null;
+            ContentPresenter? part_ContentPresenter = null;
+
+            if (TestExpander.ExpandDirection == ExpandDirection.Down)
+            {
+                part_ToggleButtonGrid = parts[3] as Grid;
+                part_ToggleButtonContentPresenter = parts[4] as ContentPresenter;
+                part_ChevronGrid = parts[5] as Grid;
+                part_ControlChevronIcon = parts[6] as TextBlock;
+                part_contentPresenterBorder = parts[7] as Border;
+                part_ContentPresenter = parts[8] as ContentPresenter;
+            }
+            else
+            {
+                part_contentPresenterBorder = parts[3] as Border;
+                part_ContentPresenter = parts[4] as ContentPresenter;
+            }
+            using (new AssertionScope())
+            {
+                //Validate expander properties
+                VerifyExpanderProperties(part_expander, expectedProperties);
+                //validate toggle button border properties
+                VerifyToggleButtonBorderProperties(part_ToggleButtonBorder, expectedProperties);
+                //validate toggle button  properties
+                VerifyToggleButtonProperties(part_ToggleButton, expectedProperties);
+                if (TestExpander.ExpandDirection == ExpandDirection.Down)
+                {
+                    //validate toggle button grid  properties
+                    VerifyToggleButtonGridProperties(part_ToggleButtonGrid, expectedProperties);
+                    //validate ToggleButton ContentPresenter properties
+                    VerifyToggleButtonContentPresenterProperties(part_ToggleButtonContentPresenter, expectedProperties);
+                    //validate toggle button ChevronGrid  properties
+                    VerifyToggleButtonChevronGridProperties(part_ChevronGrid, expectedProperties);
+                    //validate textblock properties
+                    VerifyToggleButtonTextblockProperties(part_ControlChevronIcon, expectedProperties);
+                }
+                //validate content presenter border properties
+                VerifyContentPresenterBorderProperties(part_contentPresenterBorder, expectedProperties);
+                //validate content presenter properties
+                VerifyContentPresenterProperties(part_ContentPresenter, expectedProperties);
+            }
+            }
+        #endregion
+        #region Private Methods
+
+        private void SetUpExpander()
+        {
+            TestExpander = new Expander()
+            {
+                Header = "Header Content",
+                Content = "ExpanderContent",
+                //IsExpanded = true,
+            };
+            AddControlToView(TestWindow, TestExpander);
+        }
+
+        private static T? GetChildOfType<T>(DependencyObject parent) where T : DependencyObject
+        {
+            // Loop through all the child elements of the parent
+            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(parent); i++)
+            {
+                DependencyObject child = VisualTreeHelper.GetChild(parent, i);
+
+                // If the child is of the desired type, return it
+                if (child is T)
+                {
+                    return (T)child;
+                }
+
+                // Recursively check the children of the child element
+                T? childOfChild = GetChildOfType<T>(child);
+                if (childOfChild != null)
+                {
+                    return childOfChild;
+                }
+            }
+
+            return null; // Return null if no child of the specified type is found
+        }
+        private static void VerifyExpanderProperties(Expander? part_expander, ResourceDictionary expectedProperties)
+        {
+            part_expander.Should().NotBeNull();
+            BrushComparer.Equal(part_expander.Background, (Brush)expectedProperties["Expander_Background"]).Should().BeTrue();
+            if (!BrushComparer.Equal(part_expander.Background, (Brush)expectedProperties["Expander_Background"]))
+            {
+                Console.WriteLine("part_expander.Background does not match expected value");
+                BrushComparer.LogBrushDifference(part_expander.Background, (Brush)expectedProperties["Expander_Background"]);
+            }
+            BrushComparer.Equal(part_expander.Foreground, (Brush)expectedProperties["Expander_Foreground"]).Should().BeTrue();
+            if (!BrushComparer.Equal(part_expander.Foreground, (Brush)expectedProperties["Expander_Foreground"]))
+            {
+                Console.WriteLine("part_expander.Foreground does not match expected value");
+                BrushComparer.LogBrushDifference(part_expander.Foreground, (Brush)expectedProperties["Expander_Foreground"]);
+            }
+            BrushComparer.Equal(part_expander.BorderBrush, (Brush)expectedProperties["Expander_BorderBrush"]).Should().BeTrue();
+            if (!BrushComparer.Equal(part_expander.BorderBrush, (Brush)expectedProperties["Expander_BorderBrush"]))
+            {
+                Console.WriteLine("part_expander.BorderBrush does not match expected value");
+                BrushComparer.LogBrushDifference(part_expander.BorderBrush, (Brush)expectedProperties["Expander_BorderBrush"]);
+            }
+            part_expander.BorderThickness.Should().Be((Thickness)expectedProperties["Expander_BorderThickness"]);
+            part_expander.Padding.Should().Be(expectedProperties["Expander_Padding"]);
+            part_expander.HorizontalAlignment.Should().Be((HorizontalAlignment?)expectedProperties["Expander_HorizontalAlignment"]);
+            part_expander.VerticalAlignment.Should().Be((VerticalAlignment?)expectedProperties["Expander_VerticalAlignment"]);
+            part_expander.HorizontalContentAlignment.Should().Be((HorizontalAlignment?)expectedProperties["Expander_HorizontalContentAlignment"]);
+            part_expander.VerticalContentAlignment.Should().Be((VerticalAlignment?)expectedProperties["Expander_VerticalContentAlignment"]);
+            part_expander.FontWeight.Should().Be(expectedProperties["Expander_FontWeight"]);
+        }
+        private static void VerifyToggleButtonBorderProperties(Border? part_ToggleButtonBorder, ResourceDictionary expectedProperties)
+        {
+            part_ToggleButtonBorder.Should().NotBeNull();
+            BrushComparer.Equal(part_ToggleButtonBorder.Background, (Brush)expectedProperties["ToggleButtonBorder_Background"]).Should().BeTrue();
+            if (!BrushComparer.Equal(part_ToggleButtonBorder.Background, (Brush)expectedProperties["ToggleButtonBorder_Background"]))
+            {
+                Console.WriteLine("part_ToggleButtonBorder.Background does not match expected value");
+                BrushComparer.LogBrushDifference(part_ToggleButtonBorder.Background, (Brush)expectedProperties["ToggleButtonBorder_Background"]);
+            }
+            BrushComparer.Equal(part_ToggleButtonBorder.BorderBrush, (Brush)expectedProperties["ToggleButtonBorder_BorderBrush"]).Should().BeTrue();
+            if (!BrushComparer.Equal(part_ToggleButtonBorder.BorderBrush, (Brush)expectedProperties["ToggleButtonBorder_BorderBrush"]))
+            {
+                Console.WriteLine("part_ToggleButtonBorder.BorderBrush does not match expected value");
+                BrushComparer.LogBrushDifference(part_ToggleButtonBorder.BorderBrush, (Brush)expectedProperties["ToggleButtonBorder_BorderBrush"]);
+            }
+            part_ToggleButtonBorder.BorderThickness.Should().Be((Thickness)expectedProperties["ToggleButtonBorder_BorderThickness"]);
+            part_ToggleButtonBorder.CornerRadius.Should().Be((CornerRadius)expectedProperties["ToggleButtonBorder_CornerRadius"]);
+        }
+        private static void VerifyToggleButtonProperties(ToggleButton? part_ToggleButton, ResourceDictionary expectedProperties)
+        {
+            part_ToggleButton.Should().NotBeNull();
+            BrushComparer.Equal(part_ToggleButton.Foreground, (Brush)expectedProperties["ToggleButton_Foreground"]).Should().BeTrue();
+            if (!BrushComparer.Equal(part_ToggleButton.Foreground, (Brush)expectedProperties["ToggleButton_Foreground"]))
+            {
+                Console.WriteLine("part_ToggleButton.Foreground does not match expected value");
+                BrushComparer.LogBrushDifference(part_ToggleButton.Foreground, (Brush)expectedProperties["ToggleButton_Foreground"]);
+            }
+            part_ToggleButton.Padding.Should().Be(expectedProperties["ToggleButton_Padding"]);
+            part_ToggleButton.HorizontalAlignment.Should().Be((HorizontalAlignment?)expectedProperties["ToggleButton_HorizontalAlignment"]);
+            part_ToggleButton.VerticalAlignment.Should().Be((VerticalAlignment?)expectedProperties["ToggleButton_VerticalAlignment"]);
+            part_ToggleButton.HorizontalContentAlignment.Should().Be((HorizontalAlignment?)expectedProperties["ToggleButton_HorizontalContentAlignment"]);
+            part_ToggleButton.VerticalContentAlignment.Should().Be((VerticalAlignment?)expectedProperties["ToggleButton_VerticalContentAlignment"]);
+            part_ToggleButton.FontWeight.Should().Be(expectedProperties["ToggleButton_FontWeight"]);
+            part_ToggleButton.FontSize.Should().Be((Double)expectedProperties["ToggleButton_FontSize"]);
+        }
+        private static void VerifyToggleButtonGridProperties(Grid? part_ToggleButtonGrid, ResourceDictionary expectedProperties)
+        {
+            part_ToggleButtonGrid.Should().NotBeNull();
+            BrushComparer.Equal(part_ToggleButtonGrid.Background, (Brush)expectedProperties["ToggleButtonGrid_Background"]).Should().BeTrue();
+            if (!BrushComparer.Equal(part_ToggleButtonGrid.Background, (Brush)expectedProperties["ToggleButtonGrid_Background"]))
+            {
+                Console.WriteLine("part_ToggleButtonGrid.Background does not match expected value");
+                BrushComparer.LogBrushDifference(part_ToggleButtonGrid.Background, (Brush)expectedProperties["ToggleButtonGrid_Background"]);
+            }
+        }
+        private static void VerifyToggleButtonContentPresenterProperties(ContentPresenter? part_ToggleButtonContentPresenter, ResourceDictionary expectedProperties)
+        {
+            part_ToggleButtonContentPresenter.Should().NotBeNull();
+            part_ToggleButtonContentPresenter.HorizontalAlignment.Should().Be((HorizontalAlignment?)expectedProperties["ToggleButtonContentPresenter_HorizontalAlignment"]);
+            part_ToggleButtonContentPresenter.VerticalAlignment.Should().Be((VerticalAlignment?)expectedProperties["ToggleButtonContentPresenter_VerticalAlignment"]);
+            part_ToggleButtonContentPresenter.Margin.Should().Be(expectedProperties["ToggleButtonContentPresenter_Margin"]);
+        }
+        private static void VerifyToggleButtonChevronGridProperties(Grid? part_ChevronGrid, ResourceDictionary expectedProperties)
+        {
+            part_ChevronGrid.Should().NotBeNull();
+            BrushComparer.Equal(part_ChevronGrid.Background, (Brush)expectedProperties["ChevronGrid_Background"]).Should().BeTrue();
+            if (!BrushComparer.Equal(part_ChevronGrid.Background, (Brush)expectedProperties["ChevronGrid_Background"]))
+            {
+                Console.WriteLine("part_ChevronGrid.Background does not match expected value");
+                BrushComparer.LogBrushDifference(part_ChevronGrid.Background, (Brush)expectedProperties["ChevronGrid_Background"]);
+            }
+            part_ChevronGrid.VerticalAlignment.Should().Be((VerticalAlignment?)expectedProperties["ChevronGrid_VerticalAlignment"]);
+        }
+        private static void VerifyToggleButtonTextblockProperties(TextBlock? part_ControlChevronIcon, ResourceDictionary expectedProperties)
+        {
+            part_ControlChevronIcon.Should().NotBeNull();
+            BrushComparer.Equal(part_ControlChevronIcon.Foreground, (Brush)expectedProperties["Textblock_Foreground"]).Should().BeTrue();
+            if (!BrushComparer.Equal(part_ControlChevronIcon.Foreground, (Brush)expectedProperties["Textblock_Foreground"]))
+            {
+                Console.WriteLine("part_ControlChevronIcon.Foreground does not match expected value");
+                BrushComparer.LogBrushDifference(part_ControlChevronIcon.Foreground, (Brush)expectedProperties["Textblock_Foreground"]);
+            }
+            part_ControlChevronIcon.FontSize.Should().Be((Double)expectedProperties["Textblock_FontSize"]);
+            part_ControlChevronIcon.FontFamily.Should().Be(expectedProperties["Textblock_FontFamily"]);
+            part_ControlChevronIcon.Text.Should().Be((String)expectedProperties["Textblock_Text"]);
+        }
+        private static void VerifyContentPresenterBorderProperties(Border? part_contentPresenterBorder, ResourceDictionary expectedProperties)
+        {
+            part_contentPresenterBorder.Should().NotBeNull();
+            BrushComparer.Equal(part_contentPresenterBorder.Background, (Brush)expectedProperties["ContentPresenterBorder_Background"]).Should().BeTrue();
+            if (!BrushComparer.Equal(part_contentPresenterBorder.Background, (Brush)expectedProperties["ContentPresenterBorder_Background"]))
+            {
+                Console.WriteLine("part_contentPresenterBorder.Background does not match expected value");
+                BrushComparer.LogBrushDifference(part_contentPresenterBorder.Background, (Brush)expectedProperties["ContentPresenterBorder_Background"]);
+            }
+            BrushComparer.Equal(part_contentPresenterBorder.BorderBrush, (Brush)expectedProperties["ContentPresenterBorder_BorderBrush"]).Should().BeTrue();
+            if (!BrushComparer.Equal(part_contentPresenterBorder.BorderBrush, (Brush)expectedProperties["ContentPresenterBorder_BorderBrush"]))
+            {
+                Console.WriteLine("part_contentPresenterBorder.BorderBrush does not match expected value");
+                BrushComparer.LogBrushDifference(part_contentPresenterBorder.BorderBrush, (Brush)expectedProperties["ContentPresenterBorder_BorderBrush"]);
+            }
+            part_contentPresenterBorder.BorderThickness.Should().Be((Thickness)expectedProperties["ContentPresenterBorder_BorderThickness"]);
+            part_contentPresenterBorder.CornerRadius.Should().Be((CornerRadius)expectedProperties["ContentPresenterBorder_CornerRadius"]);
+            part_contentPresenterBorder.Visibility.Should().Be((Visibility)expectedProperties["ContentPresenterBorder_Visibility"]);
+        }
+        private static void VerifyContentPresenterProperties(ContentPresenter? part_contentPresenter, ResourceDictionary expectedProperties)
+        {
+            part_contentPresenter.Should().NotBeNull();
+            part_contentPresenter.HorizontalAlignment.Should().Be((HorizontalAlignment?)expectedProperties["ContentPresenter_HorizontalAlignment"]);
+            part_contentPresenter.VerticalAlignment.Should().Be((VerticalAlignment?)expectedProperties["ContentPresenter_VerticalAlignment"]);
+            part_contentPresenter.Margin.Should().Be(expectedProperties["ContentPresenter_Margin"]);
+        }
+
+        private void SetSolidColorBrushProperties()
+        {
+            TestExpander.Background= new SolidColorBrush((Color)ColorConverter.ConvertFromString("Aqua"));
+            TestExpander.Foreground = new SolidColorBrush((Color)ColorConverter.ConvertFromString("Maroon"));
+            TestExpander.BorderBrush= new SolidColorBrush((Color)ColorConverter.ConvertFromString("Green"));
+        }
+        private void SetCustomizedProperties()
+        {
+            TestExpander.BorderThickness= new Thickness(10);
+            TestExpander.Padding= new Thickness(12, 0, 12, 0);
+            TestExpander.HorizontalContentAlignment=HorizontalAlignment.Center;
+            TestExpander.VerticalContentAlignment=VerticalAlignment.Bottom;
+            TestExpander.HorizontalAlignment=HorizontalAlignment.Center;
+            TestExpander.VerticalAlignment=VerticalAlignment.Bottom;
+            TestExpander.FontWeight = FontWeights.Bold;
+        }
+        #endregion
+            #region Private Properties
+        private Expander TestExpander { get; set; }
+        protected override string TestDataDictionaryPath => @"/Fluent.UITests;component/ControlTests/Data/ExpanderTests.xaml";
+        #endregion
+    }
+}