[Combobox] Set value if selection is cleared

src/Core/Components/List/FluentCombobox.razor.cs

@@ -111,8 +111,8 @@ public override async Task SetParametersAsync(ParameterView parameters)
 
             // Sync Value from selected option.
             // If it is null, we set it to the default value so the attribute is not deleted & the webcomponents don't throw an exception
-            var value = GetOptionValue(_currentSelectedOption);// ?? string.Empty;
-            if (value is not null && Value != value)
+            var value = GetOptionValue(_currentSelectedOption) ?? string.Empty;
+            if (Value != value)
             {
                 Value = value;
                 await ValueChanged.InvokeAsync(Value);

tests/Core/List/FluentComboboxTests.FluentCombobox_ClearSelection.verified.html

@@ -0,0 +1,5 @@
+
+<style>#myComponent::part(listbox) {  z-index: 9995 }</style>
+<fluent-combobox id="xxx" current-value="" position="below" blazor:onchange="1" blazor:elementreference="">
+  <fluent-option id="xxx" value="Contoso" blazor:onclick="2" blazor:elementreference="">Contoso</fluent-option>
+</fluent-combobox>

tests/Core/List/FluentComboboxTests.cs

@@ -49,5 +49,25 @@ public void FluentCombobox_NameAttribute()
         cut.Verify();
     }
 
+    [Fact]
+    public void FluentCombobox_ClearSelection()
+    {
+        // Arrange
+        var customer = new Customer(1, "Contoso");
+        var cut = TestContext.RenderComponent<FluentCombobox<Customer>>(parameters =>
+        {
+            parameters.Add(p => p.Id, "myComponent");
+            parameters.Add(p => p.Items, [customer]);
+            parameters.Add(p => p.OptionText, customer => customer.Name);
+            parameters.Add(p => p.SelectedOption, customer);
+        });
+
+        //Act
+        cut.SetParametersAndRender(parameters => parameters.Add(p => p.SelectedOption, null));
+
+        // Assert
+        cut.Verify();
+    }
+
     private record Customer(int Id, string Name);
 }