test: Type check for dependency properties

src/Uno.UI.Tests/DependencyProperty/Given_DependencyProperty.Type.cs

@@ -0,0 +1,105 @@
+using System;
+using System.Linq;
+using System.Reflection;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace Uno.UI.Tests;
+
+[TestClass]
+public class DependencyProperty_Type
+{
+	[TestMethod]
+	public void Check_All_DP_Data_Types()
+	{
+		var getOwnerType = GetOwnerGetter();
+
+		var asm = typeof(FrameworkElement).Assembly;
+
+		foreach (var dependencyObject in asm.DefinedTypes.Where(t => t.ImplementedInterfaces.Contains(typeof(DependencyObject))))
+		{
+			// If there is a static DependencyProperty property with name "XProperty" and also a instance property with the name "X"
+			// check whether the type of X == the "PropertyType" of the DependencyProperty property
+			var dependencyProperties = dependencyObject.DeclaredProperties
+				.Where(p => p.PropertyType == typeof(DependencyProperty) &&
+					p.Name.EndsWith("Property") &&
+					p.GetCustomAttributes(typeof(NotImplementedAttribute), true).Length == 0 &&
+					(p.GetGetMethod()?.IsStatic ?? false)
+				);
+
+			foreach (var dpInfo in dependencyProperties)
+			{
+				var associatedInstanceProperty = dependencyObject.DeclaredProperties.FirstOrDefault(
+					p => p.Name == dpInfo.Name.Substring(0, dpInfo.Name.Length - "Property".Length)
+				);
+
+				if (associatedInstanceProperty is null)
+				{
+					continue;
+				}
+
+				var type = associatedInstanceProperty?.PropertyType;
+				var dp = (DependencyProperty)dpInfo.GetValue(null);
+
+				CheckType(dp, type);
+			}
+		}
+	}
+
+	[TestMethod]
+	public void Check_All_DP_Default_Value_Types()
+	{
+		var getOwnerType = GetOwnerGetter();
+		var asm = typeof(FrameworkElement).Assembly;
+		foreach (var dependencyObject in asm.DefinedTypes.Where(t => t.ImplementedInterfaces.Contains(typeof(DependencyObject))))
+		{
+			var dependencyProperties = dependencyObject.DeclaredProperties
+				.Where(p => p.PropertyType == typeof(DependencyProperty) &&
+					p.GetCustomAttributes(typeof(NotImplementedAttribute), true).Length == 0 &&
+					(p.GetGetMethod()?.IsStatic ?? false)
+				);
+
+			foreach (var dpInfo in dependencyProperties)
+			{
+				var dp = (DependencyProperty)dpInfo.GetValue(null);
+				CheckDefaultValue(dp);
+			}
+		}
+	}
+
+	private void CheckDefaultValue(DependencyProperty property)
+	{
+		var dpSpecifiedType = property.Type;
+		var dpDefaultValue = property.GetDefaultValue(null, property.OwnerType);
+		if (dpDefaultValue is null)
+		{
+			// type needs to be a reference type
+			Assert.IsFalse(dpSpecifiedType.IsValueType);
+		}
+		else
+		{
+			// type needs to be same type or derived from it
+			Assert.IsTrue(dpSpecifiedType.IsAssignableFrom(dpDefaultValue.GetType()));
+		}
+	}
+
+	private static void CheckType(DependencyProperty dp, Type expectedType)
+	{
+		var dpSpecifiedType = dp.Type;
+
+		if (expectedType != typeof(PasswordRevealMode))
+		{
+			Assert.AreEqual(expectedType, dpSpecifiedType, $"Type mismatch for {dp.Name} on {dp.OwnerType}");
+		}
+	}
+
+	private static Func<DependencyProperty, Type> GetOwnerGetter()
+	{
+		var all = typeof(DependencyProperty).GetProperties();
+		var all2 = typeof(DependencyProperty).GetProperties(BindingFlags.NonPublic | BindingFlags.Instance);
+		var p = typeof(DependencyProperty).GetProperty("OwnerType", BindingFlags.NonPublic | BindingFlags.Instance);
+
+		return o => (Type)p.GetValue(o);
+	}
+}