fix!: Always use strict search (#12135)

BREAKING CHANGE: Xaml generator now always uses strict search

GitHub Issue (If applicable): Part of #8339
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## What is the current behavior?

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## What is the new behavior?

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Internal Issue (If applicable):
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src/SourceGenerators/Uno.UI.SourceGenerators/XamlGenerator/XamlFileGenerator.Reflection.cs

@@ -14,7 +14,7 @@ namespace Uno.UI.SourceGenerators.XamlGenerator
 	internal partial class XamlFileGenerator
 	{
 		private Func<string, INamedTypeSymbol?>? _findType;
-		private Func<XamlType, bool, INamedTypeSymbol?>? _findTypeByXamlType;
+		private Func<XamlType, INamedTypeSymbol?>? _findTypeByXamlType;
 		private Func<INamedTypeSymbol?, string, INamedTypeSymbol?>? _findPropertyTypeByOwnerSymbol;
 		private Func<XamlMember, INamedTypeSymbol?>? _findPropertyTypeByXamlMember;
 		private Func<XamlMember, IEventSymbol?>? _findEventType;
@@ -34,7 +34,7 @@ private void InitCaches()
 			_findPropertyTypeByXamlMember = Funcs.Create<XamlMember, INamedTypeSymbol?>(SourceFindPropertyType).AsLockedMemoized();
 			_findEventType = Funcs.Create<XamlMember, IEventSymbol?>(SourceFindEventType).AsLockedMemoized();
 			_findPropertyTypeByOwnerSymbol = Funcs.Create<INamedTypeSymbol?, string, INamedTypeSymbol?>(SourceFindPropertyTypeByOwnerSymbol).AsLockedMemoized();
-			_findTypeByXamlType = Funcs.Create<XamlType, bool, INamedTypeSymbol?>(SourceFindTypeByXamlType).AsLockedMemoized();
+			_findTypeByXamlType = Funcs.Create<XamlType, INamedTypeSymbol?>(SourceFindTypeByXamlType).AsLockedMemoized();
 			_findLocalizableDeclaredProperties = Funcs.Create<INamedTypeSymbol, string[]>(SourceFindLocalizableDeclaredProperties).AsLockedMemoized();
 
 			var defaultXmlNamespace = _fileDefinition
@@ -592,10 +592,10 @@ private static void ThrowOnErrorSymbol(ISymbol symbol)
 		private INamedTypeSymbol? FindType(string name)
 			=> _findType!(name);
 
-		private INamedTypeSymbol? FindType(XamlType? type, bool strictSearch = false)
-			=> type != null ? _findTypeByXamlType!(type, strictSearch) : null;
+		private INamedTypeSymbol? FindType(XamlType? type)
+			=> type != null ? _findTypeByXamlType!(type) : null;
 
-		private INamedTypeSymbol? SourceFindTypeByXamlType(XamlType type, bool strictSearch)
+		private INamedTypeSymbol? SourceFindTypeByXamlType(XamlType type)
 		{
 			if (type != null)
 			{
@@ -627,18 +627,14 @@ private static void ThrowOnErrorSymbol(ISymbol symbol)
 					return namedType;
 				}
 
-				if (!strictSearch)
+				var ns = _fileDefinition
+					.Namespaces
+					// Ensure that prefixless declaration (generally xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation") is considered first, otherwise PreferredXamlNamespace matching can go awry
+					.OrderByDescending(n => n.Prefix.IsNullOrEmpty())
+					.FirstOrDefault(n => n.Namespace == type.PreferredXamlNamespace);
+				if (ns?.Prefix is { Length: > 0 } nsPrefix)
 				{
-					// Then use fuzzy lookup
-					var ns = _fileDefinition
-						.Namespaces
-						// Ensure that prefixless declaration (generally xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation") is considered first, otherwise PreferredXamlNamespace matching can go awry
-						.OrderByDescending(n => n.Prefix.IsNullOrEmpty())
-						.FirstOrDefault(n => n.Namespace == type.PreferredXamlNamespace);
-					var isKnownNamespace = ns?.Prefix is { Length: > 0 };
-					var fullName = isKnownNamespace && ns != null ? ns.Prefix + ":" + type.Name : type.Name;
-
-					return _findType!(fullName);
+					return _findType!($"{nsPrefix}:{type.Name}");
 				}
 			}
 

src/SourceGenerators/Uno.UI.SourceGenerators/XamlGenerator/XamlFileGenerator.cs

@@ -4519,7 +4519,7 @@ private bool IsStaticMember(string fullMemberName)
 				{
 					var typeName = fullMemberName.Substring(0, lastDotIndex);
 					return _metadataHelper.FindTypeByFullName(typeName) as INamedTypeSymbol
-						?? FindType(new XamlType(_defaultXmlNamespace.Namespace, typeName, new List<XamlType>(), new XamlSchemaContext()), true);
+						?? FindType(new XamlType(_defaultXmlNamespace.Namespace, typeName, new List<XamlType>(), new XamlSchemaContext()));
 				}
 			}
 
@@ -6265,7 +6265,7 @@ private IEnumerable<XamlObjectDefinition> EnumerateSubElements(IEnumerable<XamlO
 						string closureName;
 						using (var innerWriter = CreateApplyBlock(writer, Generation.ElementStubSymbol.Value, out closureName))
 						{
-							var elementStubType = new XamlType("", "ElementStub", new List<XamlType>(), new XamlSchemaContext());
+							var elementStubType = new XamlType(XamlConstants.BaseXamlNamespace, "ElementStub", new List<XamlType>(), new XamlSchemaContext());
 
 							if (hasDataContextMarkup)
 							{