Do not coerce field value for Optional<T> with default value

src/HotChocolate/AspNetCore/src/Transport.Abstractions/OperationRequest.cs

@@ -89,11 +89,6 @@ public OperationRequest(
         Extensions = extensions;
     }
 
-    /// <summary>
-    /// Empty Operation Request.
-    /// </summary>
-    public static OperationRequest Empty { get; } = new();
-
     /// <summary>
     /// Gets the ID of a previously persisted operation that should be executed.
     /// </summary>

src/HotChocolate/AspNetCore/src/Transport.Abstractions/VariableBatchRequest.cs

@@ -89,11 +89,6 @@ public VariableBatchRequest(
         Extensions = extensions;
     }
 
-    /// <summary>
-    /// Empty Operation Request.
-    /// </summary>
-    public static OperationRequest Empty { get; } = new();
-
     /// <summary>
     /// Gets the ID of a previously persisted operation that should be executed.
     /// </summary>

src/HotChocolate/AspNetCore/test/Transport.Http.Tests/VariableBatchRequestTests.cs

@@ -5,7 +5,7 @@
 
 namespace HotChocolate.Transport.Http;
 
-public class VariableBatchRequestTestss(TestServerFactory serverFactory) : ServerTestBase(serverFactory)
+public class VariableBatchRequestTests(TestServerFactory serverFactory) : ServerTestBase(serverFactory)
 {
     [Fact]
     public async Task Should_WriteNullValues()

src/HotChocolate/Core/src/Types/Execution/Processing/VariableCoercionHelper.cs

@@ -213,7 +213,7 @@ private IValueNode CoerceInputLiteral(
 
                     foreach (var field in inputObjectType.Fields)
                     {
-                        if (field.DefaultValue is not (null or NullValueNode) && !processedFields.Contains(field.Name))
+                        if (field is { IsOptional: false, DefaultValue: not (null or NullValueNode) } && !processedFields.Contains(field.Name))
                         {
                             fields.Add(new ObjectFieldNode(field.Name, field.DefaultValue));
                         }

src/HotChocolate/Core/test/Execution.Tests/Processing/VariableCoercionHelperTests.cs

@@ -298,6 +298,61 @@ public void Coerce_Nullable_ReviewInput_Variable_With_Object()
             });
     }
 
+    [Fact]
+    public void Coerce_Empty_Input_Object_With_Optional_And_Default_Value()
+    {
+        // arrange
+        var schema = SchemaBuilder.New().AddQueryType<SomeQuery>().Create();
+
+        var variableDefinitions = new List<VariableDefinitionNode>
+        {
+            new VariableDefinitionNode(
+                null,
+                new VariableNode("input"),
+                description: null,
+                new NamedTypeNode("SomeInput"),
+                null,
+                [])
+        };
+
+        var variableValues = JsonDocument.Parse("""{"input": { }}""");
+        var coercedValues = new Dictionary<string, VariableValue>();
+        var featureProvider = new MockFeatureProvider();
+        var helper = new VariableCoercionHelper(new());
+
+        // act
+        helper.CoerceVariableValues(
+            schema,
+            variableDefinitions,
+            variableValues.RootElement,
+            coercedValues,
+            featureProvider);
+
+        // assert
+        Assert.Collection(coercedValues,
+            t =>
+            {
+                Assert.Equal("input", t.Key);
+                Assert.IsType<InputObjectType<SomeInput>>(t.Value.Type);
+                Assert.False(Assert.IsType<SomeInput>(t.Value.RuntimeValue).OptionalField.HasValue);
+                t.Value.ValueLiteral.MatchInlineSnapshot(
+                    """
+                    {
+                      field: true
+                    }
+                    """);
+            });
+    }
+
+    public sealed class SomeQuery
+    {
+        public bool HasOptionalValue(SomeInput input) => input.OptionalField.HasValue;
+    }
+
+    public sealed record SomeInput(
+        [property: DefaultValue(true)] Optional<bool> OptionalField,
+        [property: DefaultValue(true)] bool Field);
+
     [Fact]
     public void Error_When_Value_Is_Null_On_Non_Null_Variable()
     {