Improve nullability for TypeConverter.CanConvertTo (#63874)

The nullability of parameter 'destinationType' in TypeConverter.CanConvertTo(...) was changed from not-nullable to nullable during the development of .NET 6. Since a destination type supported by this TypeConverter can never be null, a NotNullWhenAttribute is added to the 'destinationType' parameter when the result value of TypeConverter.CanConvertTo(...) is 'true'. Fix #63186
dotnet · Mar 1, 2022 · ac246b1 · ac246b1
1 parent 79026a5
commit ac246b1
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Showing 39 changed files with 82 additions and 66 deletions.
diff --git a/src/libraries/System.ComponentModel.TypeConverter/ref/System.ComponentModel.TypeConverter.cs b/src/libraries/System.ComponentModel.TypeConverter/ref/System.ComponentModel.TypeConverter.cs
diff --git a/...ries/System.ComponentModel.TypeConverter/src/System/ComponentModel/BaseNumberConverter.cs b/...ries/System.ComponentModel.TypeConverter/src/System/ComponentModel/BaseNumberConverter.cs
@@ -1,6 +1,7 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 
 namespace System.ComponentModel
@@ -110,7 +111,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  return base.ConvertTo(context, culture, value, destinationType);
  }
 
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  if (destinationType != null && destinationType.IsPrimitive)
  {

diff --git a/...ies/System.ComponentModel.TypeConverter/src/System/ComponentModel/CultureInfoConverter.cs b/...ies/System.ComponentModel.TypeConverter/src/System/ComponentModel/CultureInfoConverter.cs
@@ -47,7 +47,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  /// Gets a value indicating whether this converter can convert an object to
  /// the given destination type using the context.
  /// </summary>
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/...raries/System.ComponentModel.TypeConverter/src/System/ComponentModel/DateTimeConverter.cs b/...raries/System.ComponentModel.TypeConverter/src/System/ComponentModel/DateTimeConverter.cs
@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.ComponentModel.Design.Serialization;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Reflection;
 
@@ -27,7 +28,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  /// Gets a value indicating whether this converter can convert an object
  /// to the given destination type using the context.
  /// </summary>
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/.../System.ComponentModel.TypeConverter/src/System/ComponentModel/DateTimeOffsetConverter.cs b/.../System.ComponentModel.TypeConverter/src/System/ComponentModel/DateTimeOffsetConverter.cs
@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.ComponentModel.Design.Serialization;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 
 namespace System.ComponentModel
@@ -26,7 +27,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  /// Gets a value indicating whether this converter can convert an
  /// object to the given destination type using the context.
  /// </summary>
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/...braries/System.ComponentModel.TypeConverter/src/System/ComponentModel/DecimalConverter.cs b/...braries/System.ComponentModel.TypeConverter/src/System/ComponentModel/DecimalConverter.cs
@@ -3,6 +3,7 @@
 
 using System.ComponentModel.Design.Serialization;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Reflection;
 
@@ -28,7 +29,7 @@ public class DecimalConverter : BaseNumberConverter
  /// Gets a value indicating whether this converter can convert an
  /// object to the given destination type using the context.
  /// </summary>
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/src/libraries/System.ComponentModel.TypeConverter/src/System/ComponentModel/EnumConverter.cs b/src/libraries/System.ComponentModel.TypeConverter/src/System/ComponentModel/EnumConverter.cs
@@ -47,7 +47,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  /// Gets a value indicating whether this converter can convert an object to the
  /// given destination type using the context.
  /// </summary>
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  if (destinationType == typeof(Enum[]) || destinationType == typeof(InstanceDescriptor))
  {

diff --git a/src/libraries/System.ComponentModel.TypeConverter/src/System/ComponentModel/GuidConverter.cs b/src/libraries/System.ComponentModel.TypeConverter/src/System/ComponentModel/GuidConverter.cs
@@ -3,6 +3,7 @@
 
 using System.ComponentModel.Design.Serialization;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Reflection;
 
@@ -27,7 +28,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  /// Gets a value indicating whether this converter can convert an object to
  /// the given destination type using the context.
  /// </summary>
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/...raries/System.ComponentModel.TypeConverter/src/System/ComponentModel/NullableConverter.cs b/...raries/System.ComponentModel.TypeConverter/src/System/ComponentModel/NullableConverter.cs
@@ -76,7 +76,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  /// <summary>
  /// Gets a value indicating whether this converter can convert a value object to the destination type.
  /// </summary>
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  if (destinationType == UnderlyingType)
  {

diff --git a/...raries/System.ComponentModel.TypeConverter/src/System/ComponentModel/TimeSpanConverter.cs b/...raries/System.ComponentModel.TypeConverter/src/System/ComponentModel/TimeSpanConverter.cs
@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.ComponentModel.Design.Serialization;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Reflection;
 
@@ -27,7 +28,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  /// Gets a value indicating whether this converter can convert an object to the given
  /// destination type using the context.
  /// </summary>
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/src/libraries/System.ComponentModel.TypeConverter/src/System/ComponentModel/TypeConverter.cs b/src/libraries/System.ComponentModel.TypeConverter/src/System/ComponentModel/TypeConverter.cs
@@ -32,13 +32,13 @@ public virtual bool CanConvertFrom(ITypeDescriptorContext? context, Type sourceT
  /// Gets a value indicating whether this converter can convert an object to the given
  /// destination type using the context.
  /// </summary>
- public bool CanConvertTo(Type destinationType) => CanConvertTo(null, destinationType);
+ public bool CanConvertTo([NotNullWhen(true)] Type? destinationType) => CanConvertTo(null, destinationType);
 
  /// <summary>
  /// Gets a value indicating whether this converter can convert an object to the given
  /// destination type using the context.
  /// </summary>
- public virtual bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public virtual bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(string);
  }

diff --git a/...raries/System.ComponentModel.TypeConverter/src/System/ComponentModel/TypeListConverter.cs b/...raries/System.ComponentModel.TypeConverter/src/System/ComponentModel/TypeListConverter.cs
@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.ComponentModel.Design.Serialization;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 
 namespace System.ComponentModel
@@ -37,7 +38,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  /// Gets a value indicating whether this converter can convert an object
  /// to the given destination type using the context.
  /// </summary>
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/...braries/System.ComponentModel.TypeConverter/src/System/ComponentModel/UriTypeConverter.cs b/...braries/System.ComponentModel.TypeConverter/src/System/ComponentModel/UriTypeConverter.cs
@@ -4,6 +4,7 @@
 using System.ComponentModel;
 using System.ComponentModel.Design.Serialization;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Reflection;
 
@@ -28,7 +29,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  /// Gets a value indicating whether this converter can
  /// convert an object to the given destination type using the context.
  /// </summary>
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(Uri) || destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/...braries/System.ComponentModel.TypeConverter/src/System/ComponentModel/VersionConverter.cs b/...braries/System.ComponentModel.TypeConverter/src/System/ComponentModel/VersionConverter.cs
@@ -3,6 +3,7 @@
 
 using System.ComponentModel.Design.Serialization;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Reflection;
 
@@ -27,7 +28,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  /// <para>Gets a value indicating whether this converter can
  /// convert an object to the given destination type using the context.</para>
  /// </summary>
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(Version) || destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/src/libraries/System.ComponentModel.TypeConverter/src/System/Drawing/ColorConverter.cs b/src/libraries/System.ComponentModel.TypeConverter/src/System/Drawing/ColorConverter.cs
@@ -30,7 +30,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  return sourceType == typeof(string) || base.CanConvertFrom(context, sourceType);
  }
 
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/src/libraries/System.ComponentModel.TypeConverter/src/System/Drawing/PointConverter.cs b/src/libraries/System.ComponentModel.TypeConverter/src/System/Drawing/PointConverter.cs
@@ -17,7 +17,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  return sourceType == typeof(string) || base.CanConvertFrom(context, sourceType);
  }
 
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/src/libraries/System.ComponentModel.TypeConverter/src/System/Drawing/RectangleConverter.cs b/src/libraries/System.ComponentModel.TypeConverter/src/System/Drawing/RectangleConverter.cs
@@ -17,7 +17,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  return sourceType == typeof(string) || base.CanConvertFrom(context, sourceType);
  }
 
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/src/libraries/System.ComponentModel.TypeConverter/src/System/Drawing/SizeConverter.cs b/src/libraries/System.ComponentModel.TypeConverter/src/System/Drawing/SizeConverter.cs
@@ -17,7 +17,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  return sourceType == typeof(string) || base.CanConvertFrom(context, sourceType);
  }
 
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/src/libraries/System.ComponentModel.TypeConverter/src/System/Drawing/SizeFConverter.cs b/src/libraries/System.ComponentModel.TypeConverter/src/System/Drawing/SizeFConverter.cs
@@ -17,7 +17,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  return sourceType == typeof(string) || base.CanConvertFrom(context, sourceType);
  }
 
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/...ystem/Security/Authentication/ExtendedProtection/ExtendedProtectionPolicyTypeConverter.cs b/...ystem/Security/Authentication/ExtendedProtection/ExtendedProtectionPolicyTypeConverter.cs
@@ -4,6 +4,7 @@
 using System.Collections;
 using System.ComponentModel;
 using System.ComponentModel.Design.Serialization;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Reflection;
 using System.Runtime.Versioning;
@@ -12,7 +13,7 @@ namespace System.Security.Authentication.ExtendedProtection
 {
  public class ExtendedProtectionPolicyTypeConverter : TypeConverter
  {
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  return destinationType == typeof(InstanceDescriptor) || base.CanConvertTo(context, destinationType);
  }

diff --git a/src/libraries/System.ComponentModel.TypeConverter/tests/SampleClasses.cs b/src/libraries/System.ComponentModel.TypeConverter/tests/SampleClasses.cs
@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Collections;
+using System.Diagnostics.CodeAnalysis;
 
 namespace System.ComponentModel.Tests
 {
@@ -112,7 +113,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceT
  }
  return base.CanConvertFrom(context, sourceType);
  }
- public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext context, [NotNullWhen(true)] Type? destinationType)
  {
  if (destinationType == typeof(int))
  {
@@ -189,7 +190,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceT
  }
  return base.CanConvertFrom(context, sourceType);
  }
- public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext context, [NotNullWhen(true)] Type? destinationType)
  {
  if (destinationType == typeof(int))
  {
@@ -255,7 +256,7 @@ public ClassIDerived()
 
  public class IBaseConverter : TypeConverter
  {
- public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext context, [NotNullWhen(true)] Type? destinationType)
  {
  if (destinationType == typeof(string) || destinationType == typeof(int))
  {

diff --git a/src/libraries/System.Data.Common/src/System/Data/ColumnTypeConverter.cs b/src/libraries/System.Data.Common/src/System/Data/ColumnTypeConverter.cs
@@ -59,7 +59,7 @@ public ColumnTypeConverter() { }
  /// <summary>
  /// Gets a value indicating whether this converter can convert an object to the given destination type using the context.
  /// </summary>
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType) =>
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType) =>
  destinationType == typeof(InstanceDescriptor) ||
  base.CanConvertTo(context, destinationType);
 

diff --git a/src/libraries/System.Data.Common/src/System/Data/Common/DataColumnMapping.cs b/src/libraries/System.Data.Common/src/System/Data/Common/DataColumnMapping.cs
@@ -147,7 +147,7 @@ public DataColumnMappingConverter()
  {
  }
 
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  if (typeof(InstanceDescriptor) == destinationType)
  {

diff --git a/src/libraries/System.Data.Common/src/System/Data/Common/DataTableMapping.cs b/src/libraries/System.Data.Common/src/System/Data/Common/DataTableMapping.cs
@@ -169,7 +169,7 @@ public DataTableMappingConverter()
  {
  }
 
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  if (typeof(InstanceDescriptor) == destinationType)
  {

diff --git a/src/libraries/System.Data.Common/src/System/Data/ConstraintConverter.cs b/src/libraries/System.Data.Common/src/System/Data/ConstraintConverter.cs
@@ -3,6 +3,7 @@
 
 using System.ComponentModel;
 using System.ComponentModel.Design.Serialization;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 
 namespace System.Data
@@ -16,7 +17,7 @@ public ConstraintConverter() { }
  /// Gets a value indicating whether this converter can
  /// convert an object to the given destination type using the context.
  /// </summary>
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType) =>
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType) =>
  destinationType == typeof(InstanceDescriptor) ||
  base.CanConvertTo(context, destinationType);
 

diff --git a/src/libraries/System.Data.Common/src/System/Data/PrimaryKeyTypeConverter.cs b/src/libraries/System.Data.Common/src/System/Data/PrimaryKeyTypeConverter.cs
@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.ComponentModel;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 
 namespace System.Data
@@ -15,7 +16,7 @@ public PrimaryKeyTypeConverter() : base(typeof(DataColumn[]))
 
  public override bool GetPropertiesSupported(ITypeDescriptorContext? context) => false;
 
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType) =>
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType) =>
  destinationType == typeof(string) ||
  base.CanConvertTo(context, destinationType);
 

diff --git a/src/libraries/System.Data.Common/src/System/Data/RelationshipConverter.cs b/src/libraries/System.Data.Common/src/System/Data/RelationshipConverter.cs
@@ -3,6 +3,7 @@
 
 using System.ComponentModel;
 using System.ComponentModel.Design.Serialization;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 
 namespace System.Data
@@ -18,7 +19,7 @@ public RelationshipConverter()
  /// Gets a value indicating whether this converter can
  /// convert an object to the given destination type using the context.
  /// </summary>
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  if (destinationType == typeof(InstanceDescriptor))
  {

diff --git a/src/libraries/System.Data.OleDb/src/OleDbConnectionStringBuilder.cs b/src/libraries/System.Data.OleDb/src/OleDbConnectionStringBuilder.cs
@@ -645,7 +645,7 @@ public override bool CanConvertFrom(ITypeDescriptorContext? context, Type source
  return base.ConvertFrom(context, culture, value);
  }
 
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  // Only know how to convert to the NetworkLibrary enumeration
  return ((typeof(string) == destinationType) || base.CanConvertTo(context, destinationType));
@@ -697,7 +697,7 @@ public OleDbConnectionStringBuilderConverter()
  {
  }
 
- public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
+ public override bool CanConvertTo(ITypeDescriptorContext? context, [NotNullWhen(true)] Type? destinationType)
  {
  if (typeof(System.ComponentModel.Design.Serialization.InstanceDescriptor) == destinationType)
  {