Fix deprecation of input fields / arguments

src/HotChocolate/Core/src/Types/Configuration/Validation/TypeValidationHelper.cs

@@ -31,7 +31,7 @@ public static void EnsureFieldDeprecationIsValid(
         {
             var field = type.Fields[i];
 
-            if (field.IsDeprecated && field.Type.IsNonNullType())
+            if (field.IsDeprecated && field.Type.IsNonNullType() && field.DefaultValue is null)
             {
                 errors.Add(RequiredFieldCannotBeDeprecated(type, field));
             }
@@ -49,7 +49,7 @@ public static void EnsureArgumentDeprecationIsValid(
             {
                 var argument = field.Arguments[j];
 
-                if (argument.IsDeprecated && argument.Type.IsNonNullType())
+                if (argument.IsDeprecated && argument.Type.IsNonNullType() && argument.DefaultValue is null)
                 {
                     errors.Add(RequiredArgumentCannotBeDeprecated(type, field, argument));
                 }
@@ -64,7 +64,7 @@ public static void EnsureArgumentDeprecationIsValid(
         for (var i = 0; i < type.Arguments.Count; i++)
         {
             var argument = type.Arguments[i];
-            if (argument.IsDeprecated && argument.Type.IsNonNullType())
+            if (argument.IsDeprecated && argument.Type.IsNonNullType() && argument.DefaultValue is null)
             {
                 errors.Add(RequiredArgumentCannotBeDeprecated(type, argument));
             }

src/HotChocolate/Core/src/Types/Types/Descriptors/Contracts/IArgumentDescriptor.cs

@@ -36,7 +36,7 @@ public interface IArgumentDescriptor
     /// <summary>
     /// Marks the argument as deprecated
     /// <remarks>
-    /// The argument must be nullable. Non-Nullable arguments cannot be deprecated
+    /// The argument must be nullable or have a default value. Otherwise the argument cannot be deprecated
     /// </remarks>
     /// <example>
     /// <code lang="csharp">

src/HotChocolate/Core/src/Types/Types/Descriptors/Contracts/IInputFieldDescriptor.cs

@@ -33,7 +33,7 @@ public interface IInputFieldDescriptor
     /// <summary>
     /// Marks the field as deprecated
     /// <remarks>
-    /// The field must be nullable. Non-Nullable field cannot be deprecated
+    /// The field must be nullable or have a default value. Otherwise the field cannot be deprecated
     /// </remarks>
     /// <example>
     /// <code lang="csharp">

src/HotChocolate/Utilities/src/Utilities.Introspection/IntrospectionFormatter.cs

@@ -169,7 +169,9 @@ private static IReadOnlyList<InputValueDefinitionNode> CreateInputValues(
                 CreateDescription(field.Description),
                 CreateTypeReference(field.Type),
                 ParseDefaultValue(field.DefaultValue),
-                Array.Empty<DirectiveNode>()
+                CreateDeprecatedDirective(
+                    field.IsDeprecated,
+                    field.DeprecationReason)
             ));
         }
 

src/HotChocolate/Utilities/src/Utilities.Introspection/IntrospectionQueryBuilder.cs

@@ -170,7 +170,7 @@ private static FragmentDefinitionNode BuildFullTypeFragment(bool includeDeprecat
                     new FieldNode("name"),
                     new FieldNode("description"),
                     CreateFields(includeDeprecatedArgs),
-                    CreateInputFields(),
+                    CreateInputFields(includeDeprecatedArgs),
                     CreateInterfacesField(),
                     CreateEnumValuesField(),
                     CreatePossibleTypesField(),
@@ -250,21 +250,41 @@ private static FieldNode CreateTypeField()
                         Array.Empty<DirectiveNode>()),
                 }));
 
-    private static FieldNode CreateInputFields()
-        => new FieldNode(
-            new NameNode("inputFields"),
-            null,
-            null,
-            Array.Empty<DirectiveNode>(),
-            Array.Empty<ArgumentNode>(),
-            new SelectionSetNode(
-                new ISelectionNode[]
+    private static FieldNode CreateInputFields(bool includeDeprecatedFields)
+        => includeDeprecatedFields
+            ? new FieldNode(
+                new NameNode("inputFields"),
+                null,
+                null,
+                Array.Empty<DirectiveNode>(),
+                new[]
                 {
-                    new FragmentSpreadNode(
-                        null,
-                        new NameNode("InputValue"),
-                        Array.Empty<DirectiveNode>()),
-                }));
+                    new ArgumentNode("includeDeprecated", true),
+                },
+                new SelectionSetNode(
+                    new ISelectionNode[]
+                    {
+                        new FragmentSpreadNode(
+                            null,
+                            new NameNode("InputValue"),
+                            Array.Empty<DirectiveNode>()),
+                        new FieldNode("isDeprecated"),
+                        new FieldNode("deprecationReason"),
+                    }))
+            : new FieldNode(
+                new NameNode("inputFields"),
+                null,
+                null,
+                Array.Empty<DirectiveNode>(),
+                Array.Empty<ArgumentNode>(),
+                new SelectionSetNode(
+                    new ISelectionNode[]
+                    {
+                        new FragmentSpreadNode(
+                            null,
+                            new NameNode("InputValue"),
+                            Array.Empty<DirectiveNode>()),
+                    }));
 
     private static FieldNode CreateInterfacesField()
         => new FieldNode(

src/HotChocolate/Utilities/src/Utilities.Introspection/Models/InputField.cs

@@ -9,5 +9,7 @@ internal class InputField
     public string Description { get; set; }
     public TypeRef Type { get; set; }
     public string DefaultValue { get; set; }
+    public bool IsDeprecated { get; set; }
+    public string DeprecationReason { get; set; }
 }
 #pragma warning restore CA1812

website/src/docs/hotchocolate/v13/defining-a-schema/versioning.md

@@ -17,9 +17,9 @@ type Query {
 
 ```
 
-# Deprecating fields
+# Deprecation
 
-Fields can be deprecated like the following.
+You can deprecate output fields, input fields, arguments and enum values.
 
 <ExampleTabs>
 <Annotation>
@@ -35,6 +35,8 @@ public class Query
 }
 ```
 
+> Note: .NET's `[Obsolete("reason")]` attribute is handled in the same way as  `[GraphQLDeprecated("reason")]`.
+
 </Annotation>
 <Code>
 
@@ -70,4 +72,5 @@ services
 </Schema>
 </ExampleTabs>
 
-> Note: It is currently not possible to deprecate input values, such as arguments.
+
+> Warning: You can not deprecate non-null arguments or input fields without a default value.