Adds @serializeAs for scalar serialization. (#8867)

Author: michaelstaib

src/HotChocolate/Core/src/Execution.Abstractions/Execution/OperationRequestBuilder.cs

@@ -1,4 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
+using System.Runtime.CompilerServices;
+using System.Text.Json;
 using HotChocolate.Features;
 using HotChocolate.Language;
 
@@ -175,6 +177,66 @@ public OperationRequestBuilder SetVariableValues(
         return this;
     }
 
+    /// <summary>
+    /// Sets the variable values for the GraphQL request.
+    /// </summary>
+    /// <param name="variableValues">
+    /// The variable values for the GraphQL request.
+    /// </param>
+    /// <returns>
+    /// Returns this instance of <see cref="OperationRequestBuilder" /> for configuration chaining.
+    /// </returns>
+    public OperationRequestBuilder SetVariableValuesJson(
+        [StringSyntax("json")] string variableValues)
+    {
+        ArgumentException.ThrowIfNullOrEmpty(variableValues);
+
+        using var document = JsonDocument.Parse(variableValues);
+        return SetVariableValuesJson(document);
+    }
+
+    /// <summary>
+    /// Sets the variable values for the GraphQL request.
+    /// </summary>
+    /// <param name="variableValues">
+    /// The variable values for the GraphQL request.
+    /// </param>
+    /// <returns>
+    /// Returns this instance of <see cref="OperationRequestBuilder" /> for configuration chaining.
+    /// </returns>
+    public OperationRequestBuilder SetVariableValuesJson(
+        JsonDocument variableValues)
+    {
+        ArgumentNullException.ThrowIfNull(variableValues);
+
+        if (variableValues.RootElement.ValueKind is not (JsonValueKind.Null or JsonValueKind.Object))
+        {
+            throw new ArgumentException(
+                "The JSON document must be either null or an array of variable sets.",
+                nameof(variableValues));
+        }
+
+        if (variableValues.RootElement.ValueKind is JsonValueKind.Null)
+        {
+            _variableValues = null;
+            _readOnlyVariableValues = null;
+            return this;
+        }
+
+        var parser = new JsonValueParser();
+        var objectValue = (ObjectValueNode)parser.Parse(variableValues.RootElement);
+        var values = new Dictionary<string, object?>();
+
+        foreach (var field in objectValue.Fields)
+        {
+            values[field.Name.Value] = field.Value;
+        }
+
+        _variableValues = [values];
+        _readOnlyVariableValues = null;
+        return this;
+    }
+
     /// <summary>
     /// Sets the variable values for the GraphQL request.
     /// </summary>
@@ -200,6 +262,78 @@ public OperationRequestBuilder SetVariableValuesSet(
         return this;
     }
 
+    /// <summary>
+    /// Sets the variable values for the GraphQL request.
+    /// </summary>
+    /// <param name="variableValues">
+    /// The variable values for the GraphQL request.
+    /// </param>
+    /// <returns>
+    /// Returns this instance of <see cref="OperationRequestBuilder" /> for configuration chaining.
+    /// </returns>
+    public OperationRequestBuilder SetVariableValuesSetJson([StringSyntax("json")] string variableValues)
+    {
+        ArgumentException.ThrowIfNullOrEmpty(variableValues);
+
+        using var document = JsonDocument.Parse(variableValues);
+        return SetVariableValuesSetJson(document);
+    }
+
+    /// <summary>
+    /// Sets the variable values for the GraphQL request.
+    /// </summary>
+    /// <param name="variableValues">
+    /// The variable values for the GraphQL request.
+    /// </param>
+    /// <returns>
+    /// Returns this instance of <see cref="OperationRequestBuilder" /> for configuration chaining.
+    /// </returns>
+    public OperationRequestBuilder SetVariableValuesSetJson(JsonDocument variableValues)
+    {
+        ArgumentNullException.ThrowIfNull(variableValues);
+
+        if (variableValues.RootElement.ValueKind is not (JsonValueKind.Null or JsonValueKind.Array))
+        {
+            throw new ArgumentException(
+                "The JSON document must be either null or an array of variable sets.",
+                nameof(variableValues));
+        }
+
+        if (variableValues.RootElement.ValueKind is JsonValueKind.Null)
+        {
+            _variableValues = null;
+            _readOnlyVariableValues = null;
+            return this;
+        }
+
+        var parser = new JsonValueParser();
+        var sets = new List<IReadOnlyDictionary<string, object?>>();
+
+        foreach (var element in variableValues.RootElement.EnumerateArray())
+        {
+            if (element.ValueKind != JsonValueKind.Object)
+            {
+                throw new ArgumentException(
+                    "Each variable set must be a JSON object.",
+                    nameof(variableValues));
+            }
+
+            var objectValue = (ObjectValueNode)parser.Parse(element);
+            var values = new Dictionary<string, object?>();
+
+            foreach (var field in objectValue.Fields)
+            {
+                values[field.Name.Value] = field.Value;
+            }
+
+            sets.Add(values);
+        }
+
+        _variableValues = sets;
+        _readOnlyVariableValues = null;
+        return this;
+    }
+
     /// <summary>
     /// Sets the GraphQL request extension data.
     /// </summary>

src/HotChocolate/Core/src/Execution/DependencyInjection/RequestExecutorBuilderExtensions.Composite.cs

@@ -23,5 +23,6 @@ public static IRequestExecutorBuilder AddSourceSchemaDefaults(
             o.ApplyShareableToConnections = true;
             o.ApplyShareableToPageInfo = true;
             o.ApplyShareableToNodeFields = true;
+            o.ApplySerializeAsToScalars = true;
         });
 }

src/HotChocolate/Core/src/Types.Abstractions/Types/IScalarTypeDefinition.cs

@@ -2,13 +2,30 @@
 
 namespace HotChocolate.Types;
 
+/// <summary>
+/// Represents a scalar type definition in the GraphQL schema.
+/// </summary>
 public interface IScalarTypeDefinition
     : IOutputTypeDefinition
     , IInputTypeDefinition
     , ISyntaxNodeProvider<ScalarTypeDefinitionNode>
 {
+    /// <summary>
+    /// Gets the URI that specifies the behavior and constraints of this scalar type.
+    /// </summary>
     Uri? SpecifiedBy { get; }
 
+    /// <summary>
+    /// Gets the possible types that this scalar can serialize to.
+    /// </summary>
+    ScalarSerializationType SerializationType { get; }
+
+    /// <summary>
+    /// Gets the ECMA-262 regex pattern that the serialized scalar value conforms
+    /// to if its of the serialization type <see cref="ScalarSerializationType.String"/>.
+    /// </summary>
+    string? Pattern { get; }
+
     /// <summary>
     /// Checks if the value is an instance of this type.
     /// </summary>

src/HotChocolate/Core/src/Types.Abstractions/Types/ScalarSerializationType.cs

@@ -0,0 +1,48 @@
+namespace HotChocolate.Types;
+
+/// <summary>
+/// Defines the possible serialization types for GraphQL scalar values.
+/// </summary>
+[Flags]
+public enum ScalarSerializationType
+{
+    /// <summary>
+    /// No serialization type is defined.
+    /// </summary>
+    Undefined = 0,
+
+    /// <summary>
+    /// The scalar serializes to a string value.
+    /// </summary>
+    String = 1,
+
+    /// <summary>
+    /// The scalar serializes to a boolean value.
+    /// </summary>
+    Boolean = 2,
+
+    /// <summary>
+    /// The scalar serializes to an integer value.
+    /// </summary>
+    Int = 4,
+
+    /// <summary>
+    /// The scalar serializes to a floating-point value.
+    /// </summary>
+    Float = 8,
+
+    /// <summary>
+    /// The scalar serializes to an object value.
+    /// </summary>
+    Object = 16,
+
+    /// <summary>
+    /// The scalar serializes to a list value.
+    /// </summary>
+    List = 32,
+
+    /// <summary>
+    /// The scalar can serialize as any possible primitive type.
+    /// </summary>
+    Any = String | Boolean | Int | Float | Object | List
+}

src/HotChocolate/Core/src/Types/IReadOnlySchemaOptions.cs

@@ -222,4 +222,9 @@ public interface IReadOnlySchemaOptions
     /// field when Global Object Identification is turned on.
     /// </summary>
     bool ApplyShareableToNodeFields { get; }
+
+    /// <summary>
+    /// Applies the @serializeAs directive to scalar types that specify a serialization format.
+    /// </summary>
+    bool ApplySerializeAsToScalars { get; }
 }