[Fusion] Add onError to source schema capabilities

src/HotChocolate/Fusion/src/Fusion.Connectors.InMemory/InMemorySourceSchemaClient.cs

@@ -31,6 +31,7 @@ public sealed class InMemorySourceSchemaClient : ISourceSchemaClient
 
     private readonly RequestExecutorProxy _executor;
     private readonly JsonResultFormatter _formatter;
+    private readonly ErrorHandlingMode? _onError;
     private bool _disposed;
 
     /// <summary>
@@ -42,15 +43,20 @@ public sealed class InMemorySourceSchemaClient : ISourceSchemaClient
     /// <param name="formatter">
     /// The JSON result formatter used to serialize execution results.
     /// </param>
+    /// <param name="onError">
+    /// The error handling mode requested by the source schema.
+    /// </param>
     public InMemorySourceSchemaClient(
         RequestExecutorProxy executor,
-        JsonResultFormatter formatter)
+        JsonResultFormatter formatter,
+        ErrorHandlingMode? onError = null)
     {
         ArgumentNullException.ThrowIfNull(executor);
         ArgumentNullException.ThrowIfNull(formatter);
 
         _executor = executor;
         _formatter = formatter;
+        _onError = onError;
     }
 
     /// <inheritdoc />
@@ -68,7 +74,7 @@ public async ValueTask<SourceSchemaClientResponse> ExecuteAsync(
         ObjectDisposedException.ThrowIf(_disposed, this);
 
         ChunkedArrayWriter? buffer = null;
-        var operationRequest = BuildOperationRequest(context, request, ref buffer);
+        var operationRequest = BuildOperationRequest(context, request, _onError, ref buffer);
 
         try
         {
@@ -103,7 +109,7 @@ public async IAsyncEnumerable<BatchStreamResult> ExecuteBatchStreamAsync(
         {
             for (var i = 0; i < requests.Length; i++)
             {
-                operationRequests[i] = BuildOperationRequest(context, requests[i], ref buffer);
+                operationRequests[i] = BuildOperationRequest(context, requests[i], _onError, ref buffer);
             }
         }
         catch
@@ -221,6 +227,7 @@ public ValueTask DisposeAsync()
     private static IOperationRequest BuildOperationRequest(
         OperationPlanContext context,
         SourceSchemaClientRequest request,
+        ErrorHandlingMode? onError,
         ref ChunkedArrayWriter? buffer)
     {
         IFeatureCollection? features = null;
@@ -236,6 +243,7 @@ private static IOperationRequest BuildOperationRequest(
         {
             return OperationRequest.FromSourceText(
                 request.OperationSourceText,
+                errorHandlingMode: onError,
                 features: features);
         }
 
@@ -247,13 +255,15 @@ private static IOperationRequest BuildOperationRequest(
             {
                 return OperationRequest.FromSourceText(
                     request.OperationSourceText,
+                    errorHandlingMode: onError,
                     variableValues: JsonDocument.Parse(sequence));
             }
 
             buffer ??= new ChunkedArrayWriter();
             var cleanedJson = StripFileMarkers(buffer, sequence);
             return OperationRequest.FromSourceText(
                 request.OperationSourceText,
+                errorHandlingMode: onError,
                 variableValues: JsonDocument.Parse(cleanedJson.AsSequence()),
                 features: features);
         }
@@ -279,6 +289,7 @@ private static IOperationRequest BuildOperationRequest(
         return VariableBatchRequest.FromSourceText(
             request.OperationSourceText,
             variableValues: JsonDocument.Parse(variableSequence),
+            errorHandlingMode: onError,
             features: features);
     }
 

src/HotChocolate/Fusion/src/Fusion.Connectors.InMemory/InMemorySourceSchemaClientConfiguration.cs

@@ -1,3 +1,5 @@
+using HotChocolate.Language;
+
 namespace HotChocolate.Fusion.Execution.Clients;
 
 /// <summary>
@@ -11,19 +13,29 @@ public sealed class InMemorySourceSchemaClientConfiguration : ISourceSchemaClien
     /// </summary>
     /// <param name="name">The name of the source schema.</param>
     /// <param name="supportedOperations">The supported operation types.</param>
+    /// <param name="onError">
+    /// The error handling mode requested by the source schema.
+    /// </param>
     public InMemorySourceSchemaClientConfiguration(
         string name,
-        SupportedOperationType supportedOperations = SupportedOperationType.All)
+        SupportedOperationType supportedOperations = SupportedOperationType.All,
+        ErrorHandlingMode? onError = null)
     {
         ArgumentException.ThrowIfNullOrEmpty(name);
 
         Name = name;
         SupportedOperations = supportedOperations;
+        OnError = onError;
     }
 
     /// <inheritdoc />
     public string Name { get; }
 
     /// <inheritdoc />
     public SupportedOperationType SupportedOperations { get; }
+
+    /// <summary>
+    /// Gets the error handling mode requested by the source schema.
+    /// </summary>
+    public ErrorHandlingMode? OnError { get; }
 }

src/HotChocolate/Fusion/src/Fusion.Connectors.InMemory/InMemorySourceSchemaClientFactory.cs

@@ -39,6 +39,6 @@ protected override ISourceSchemaClient CreateClient(
         InMemorySourceSchemaClientConfiguration configuration)
     {
         var proxy = new RequestExecutorProxy(_executorProvider, _executorEvents, configuration.Name);
-        return new InMemorySourceSchemaClient(proxy, _formatter);
+        return new InMemorySourceSchemaClient(proxy, _formatter, configuration.OnError);
     }
 }

src/HotChocolate/Fusion/src/Fusion.Execution/Configuration/Parsers/HttpSourceSchemaClientConfigurationParser.cs

@@ -3,12 +3,13 @@
 using System.Net.Http.Headers;
 using System.Text.Json;
 using HotChocolate.Fusion.Execution.Clients;
+using HotChocolate.Language;
 
 namespace HotChocolate.Fusion.Configuration.Parsers;
 
 /// <summary>
 /// Built-in parser that claims the <c>http</c> transport and produces a
-/// <see cref="SourceSchemaHttpClientConfiguration"/>.
+/// <see cref="HttpSourceSchemaClientConfiguration"/>.
 /// </summary>
 internal sealed class HttpSourceSchemaClientConfigurationParser : ISourceSchemaClientConfigurationParser
 {
@@ -27,16 +28,17 @@ public bool TryParse(
         return false;
     }
 
-    private static SourceSchemaHttpClientConfiguration CreateHttpClientConfiguration(
+    private static HttpSourceSchemaClientConfiguration CreateHttpClientConfiguration(
         string schemaName,
         JsonElement http)
     {
-        var clientName = SourceSchemaHttpClientConfiguration.DefaultClientName;
+        var clientName = HttpSourceSchemaClientConfiguration.DefaultClientName;
         var capabilities = SourceSchemaClientCapabilities.All;
         var supportedOperations = SupportedOperationType.All;
         ImmutableArray<MediaTypeWithQualityHeaderValue>? defaultAcceptHeaderValues = null;
         ImmutableArray<MediaTypeWithQualityHeaderValue>? batchingAcceptHeaderValues = null;
         ImmutableArray<MediaTypeWithQualityHeaderValue>? subscriptionAcceptHeaderValues = null;
+        ErrorHandlingMode? onError = null;
 
         if (http.TryGetProperty("clientName", out var clientNameProperty)
             && clientNameProperty.ValueKind is JsonValueKind.String
@@ -90,6 +92,14 @@ private static SourceSchemaHttpClientConfiguration CreateHttpClientConfiguration
                 }
             }
 
+            if (capabilitiesElement.TryGetProperty("onError", out var onErrorElement)
+                && onErrorElement.ValueKind is JsonValueKind.String
+                && onErrorElement.GetString() is { } onErrorValue
+                && Enum.TryParse<ErrorHandlingMode>(onErrorValue, ignoreCase: true, out var parsedOnError))
+            {
+                onError = parsedOnError;
+            }
+
             if (capabilitiesElement.TryGetProperty("subscriptions", out var subscriptionsElement))
             {
                 if (subscriptionsElement.TryGetProperty("supported", out var supported)
@@ -112,12 +122,13 @@ private static SourceSchemaHttpClientConfiguration CreateHttpClientConfiguration
             }
         }
 
-        return new SourceSchemaHttpClientConfiguration(
+        return new HttpSourceSchemaClientConfiguration(
             name: schemaName,
             httpClientName: clientName,
             baseAddress: new Uri(http.GetProperty("url").GetString()!),
             supportedOperations: supportedOperations,
             capabilities: capabilities,
+            onError: onError,
             defaultAcceptHeaderValues: defaultAcceptHeaderValues,
             batchingAcceptHeaderValues: batchingAcceptHeaderValues,
             subscriptionAcceptHeaderValues: subscriptionAcceptHeaderValues);

src/HotChocolate/Fusion/src/Fusion.Execution/DependencyInjection/CoreFusionGatewayBuilderExtensions.SourceSchemaClients.cs

@@ -4,6 +4,7 @@
 using HotChocolate.Fusion.Execution;
 using HotChocolate.Fusion.Execution.Clients;
 using HotChocolate.Fusion.Execution.Nodes;
+using HotChocolate.Language;
 
 namespace Microsoft.Extensions.DependencyInjection;
 
@@ -27,6 +28,9 @@ public static partial class CoreFusionGatewayBuilderExtensions
     /// <param name="capabilities">
     /// The client capabilities.
     /// </param>
+    /// <param name="onError">
+    /// The error handling mode requested by the source schema.
+    /// </param>
     /// <param name="defaultAcceptHeaderValues">
     /// The <c>Accept</c> header values sent in case of a single, non-Subscription GraphQL request.
     /// </param>
@@ -54,6 +58,7 @@ public static IFusionGatewayBuilder AddHttpClientConfiguration(
         Uri baseAddress,
         SupportedOperationType supportedOperations = SupportedOperationType.All,
         SourceSchemaClientCapabilities capabilities = SourceSchemaClientCapabilities.All,
+        ErrorHandlingMode? onError = null,
         ImmutableArray<MediaTypeWithQualityHeaderValue>? defaultAcceptHeaderValues = null,
         ImmutableArray<MediaTypeWithQualityHeaderValue>? batchingAcceptHeaderValues = null,
         ImmutableArray<MediaTypeWithQualityHeaderValue>? subscriptionAcceptHeaderValues = null,
@@ -67,6 +72,7 @@ public static IFusionGatewayBuilder AddHttpClientConfiguration(
             baseAddress,
             supportedOperations,
             capabilities,
+            onError,
             defaultAcceptHeaderValues,
             batchingAcceptHeaderValues,
             subscriptionAcceptHeaderValues,
@@ -95,6 +101,9 @@ public static IFusionGatewayBuilder AddHttpClientConfiguration(
     /// <param name="capabilities">
     /// The client capabilities.
     /// </param>
+    /// <param name="onError">
+    /// The error handling mode requested by the source schema.
+    /// </param>
     /// <param name="defaultAcceptHeaderValues">
     /// The <c>Accept</c> header values sent in case of a single, non-Subscription GraphQL request.
     /// </param>
@@ -123,6 +132,7 @@ public static IFusionGatewayBuilder AddHttpClientConfiguration(
         Uri baseAddress,
         SupportedOperationType supportedOperations = SupportedOperationType.All,
         SourceSchemaClientCapabilities capabilities = SourceSchemaClientCapabilities.All,
+        ErrorHandlingMode? onError = null,
         ImmutableArray<MediaTypeWithQualityHeaderValue>? defaultAcceptHeaderValues = null,
         ImmutableArray<MediaTypeWithQualityHeaderValue>? batchingAcceptHeaderValues = null,
         ImmutableArray<MediaTypeWithQualityHeaderValue>? subscriptionAcceptHeaderValues = null,
@@ -137,12 +147,13 @@ public static IFusionGatewayBuilder AddHttpClientConfiguration(
 
         return AddHttpClientConfiguration(
             builder,
-            new SourceSchemaHttpClientConfiguration(
+            new HttpSourceSchemaClientConfiguration(
                 name,
                 httpClientName,
                 baseAddress,
                 supportedOperations,
                 capabilities,
+                onError,
                 defaultAcceptHeaderValues,
                 batchingAcceptHeaderValues,
                 subscriptionAcceptHeaderValues,
@@ -165,7 +176,7 @@ public static IFusionGatewayBuilder AddHttpClientConfiguration(
     /// </returns>
     public static IFusionGatewayBuilder AddHttpClientConfiguration(
         this IFusionGatewayBuilder builder,
-        SourceSchemaHttpClientConfiguration configuration)
+        HttpSourceSchemaClientConfiguration configuration)
     {
         ArgumentNullException.ThrowIfNull(builder);
         ArgumentNullException.ThrowIfNull(configuration);
@@ -187,7 +198,7 @@ public static IFusionGatewayBuilder AddHttpClientConfiguration(
     /// </returns>
     public static IFusionGatewayBuilder AddHttpClientConfiguration(
         this IFusionGatewayBuilder builder,
-        Func<IServiceProvider, SourceSchemaHttpClientConfiguration> create)
+        Func<IServiceProvider, HttpSourceSchemaClientConfiguration> create)
     {
         ArgumentNullException.ThrowIfNull(builder);
         ArgumentNullException.ThrowIfNull(create);