Aligned Fusion more with the Fusion spec.

src/HotChocolate/Fusion/src/Abstractions/FusionDirectiveArgumentNames.cs

@@ -11,9 +11,9 @@ internal static class FusionDirectiveArgumentNames
     public const string NameArg = "name";
 
     /// <summary>
-    /// Gets the name of the client name argument.
+    /// Gets the name of the client grouping argument.
     /// </summary>
-    public const string ClientNameArg = "clientName";
+    public const string ClientGroupArg = "group";
 
     /// <summary>
     /// Gets the name of the select argument.
@@ -66,7 +66,7 @@ internal static class FusionDirectiveArgumentNames
     public const string VersionArg = "version";
 
     /// <summary>
-    /// Gets the name of the base address argument.
+    /// Gets the name of the location argument.
     /// </summary>
-    public const string BaseAddressArg = "baseAddress";
+    public const string LocationArg = "location";
 }

src/HotChocolate/Fusion/src/Abstractions/FusionEnumValueNames.cs

@@ -6,22 +6,17 @@ namespace HotChocolate.Fusion;
 internal static class FusionEnumValueNames
 {
     /// <summary>
-    /// Gets the name of the query resolver kind.
+    /// Gets the name of the fetch resolver kind.
     /// </summary>
-    public const string Query = "QUERY";
+    public const string Fetch = "FETCH";
 
     /// <summary>
     /// Gets the name of the batch resolver kind.
     /// </summary>
     public const string Batch = "BATCH";
 
     /// <summary>
-    /// Gets the name of the batch by key resolver kind.
+    /// Gets the name of the subscribe resolver kind.
     /// </summary>
-    public const string BatchByKey = "BATCH_BY_KEY";
-
-    /// <summary>
-    /// Gets the name of the subscription resolver kind.
-    /// </summary>
-    public const string Subscription = "SUBSCRIPTION";
+    public const string Subscribe = "SUBSCRIBE";
 }

src/HotChocolate/Fusion/src/Abstractions/FusionTypeBaseNames.cs

@@ -36,14 +36,9 @@ internal static class FusionTypeBaseNames
     public static string ReEncodeIdDirective = "reEncodeId";
 
     /// <summary>
-    /// The base name of the HTTP directive.
+    /// The base name of the transport directive.
     /// </summary>
-    public const string HttpDirective = "httpClient";
-
-    /// <summary>
-    /// The base name of the HTTP directive.
-    /// </summary>
-    public const string WebSocketDirective = "webSocketClient";
+    public const string TransportDirective = "transport";
 
     /// <summary>
     /// The base name of the fusion directive.

src/HotChocolate/Fusion/src/Abstractions/FusionTypeNames.cs

@@ -1,4 +1,3 @@
-using System.Data;
 using System.Diagnostics.CodeAnalysis;
 using HotChocolate.Language;
 using HotChocolate.Utilities;
@@ -21,8 +20,7 @@ private FusionTypeNames(
         string isDirective,
         string nodeDirective,
         string reEncodeIdDirective,
-        string httpDirective,
-        string webSocketDirective,
+        string transportDirective,
         string fusionDirective,
         string selectionScalar,
         string selectionSetScalar,
@@ -39,8 +37,7 @@ private FusionTypeNames(
         IsDirective = isDirective;
         NodeDirective = nodeDirective;
         ReEncodeIdDirective = reEncodeIdDirective;
-        HttpDirective = httpDirective;
-        WebSocketDirective = webSocketDirective;
+        TransportDirective = transportDirective;
         FusionDirective = fusionDirective;
         SelectionScalar = selectionScalar;
         SelectionSetScalar = selectionSetScalar;
@@ -56,8 +53,7 @@ private FusionTypeNames(
         _fusionDirectives.Add(isDirective);
         _fusionDirectives.Add(nodeDirective);
         _fusionDirectives.Add(reEncodeIdDirective);
-        _fusionDirectives.Add(httpDirective);
-        _fusionDirectives.Add(webSocketDirective);
+        _fusionDirectives.Add(transportDirective);
         _fusionDirectives.Add(fusionDirective);
 
         _fusionTypes.Add(selectionScalar);
@@ -106,14 +102,9 @@ private FusionTypeNames(
 
 
     /// <summary>
-    /// Gets the name of the http directive.
+    /// Gets the name of the transport directive.
     /// </summary>
-    public string HttpDirective { get; }
-
-    /// <summary>
-    /// Gets the name of the http directive.
-    /// </summary>
-    public string WebSocketDirective { get; }
+    public string TransportDirective { get; }
 
     /// <summary>
     /// Gets the name of the fusion directive.
@@ -205,8 +196,7 @@ public static FusionTypeNames Create(string? prefix = null, bool prefixSelf = fa
                 $"{prefix}_{FusionTypeBaseNames.IsDirective}",
                 $"{prefix}_{FusionTypeBaseNames.NodeDirective}",
                 $"{prefix}_{FusionTypeBaseNames.ReEncodeIdDirective}",
-                $"{prefix}_{FusionTypeBaseNames.HttpDirective}",
-                $"{prefix}_{FusionTypeBaseNames.WebSocketDirective}",
+                $"{prefix}_{FusionTypeBaseNames.TransportDirective}",
                 prefixSelf
                     ? $"{prefix}_{FusionTypeBaseNames.FusionDirective}"
                     : FusionTypeBaseNames.FusionDirective,
@@ -227,8 +217,7 @@ public static FusionTypeNames Create(string? prefix = null, bool prefixSelf = fa
             FusionTypeBaseNames.IsDirective,
             FusionTypeBaseNames.NodeDirective,
             FusionTypeBaseNames.ReEncodeIdDirective,
-            FusionTypeBaseNames.HttpDirective,
-            FusionTypeBaseNames.WebSocketDirective,
+            FusionTypeBaseNames.TransportDirective,
             FusionTypeBaseNames.FusionDirective,
             $"_{FusionTypeBaseNames.Selection}",
             $"_{FusionTypeBaseNames.SelectionSet}",

src/HotChocolate/Fusion/src/Composition/Entities/EntityResolverKind.cs

@@ -4,6 +4,5 @@ public enum EntityResolverKind
 {
     Single = 0,
     Batch = 1,
-    BatchWithKey = 2,
-    Subscription = 3
+    Subscribe = 2
 }

src/HotChocolate/Fusion/src/Composition/FusionTypes.cs

@@ -36,16 +36,22 @@ public FusionTypes(Schema fusionGraph, string? prefix = null, bool prefixSelf =
                 nameof(fusionGraph));
         }
 
-        if (!_fusionGraph.Types.TryGetType<ScalarType>(SpecScalarTypes.Boolean, out var boolean))
+        if (!_fusionGraph.Types.TryGetType<ScalarType>(SpecScalarTypes.Boolean, out var booleanType))
         {
-            boolean = new ScalarType(SpecScalarTypes.Boolean) { IsSpecScalar = true };
-            _fusionGraph.Types.Add(boolean);
+            booleanType = new ScalarType(SpecScalarTypes.Boolean) { IsSpecScalar = true };
+            _fusionGraph.Types.Add(booleanType);
         }
 
-        if (!_fusionGraph.Types.TryGetType<ScalarType>(SpecScalarTypes.Int, out var integer))
+        if (!_fusionGraph.Types.TryGetType<ScalarType>(SpecScalarTypes.Int, out var intType))
         {
-            integer = new ScalarType(SpecScalarTypes.Int) { IsSpecScalar = true };
-            _fusionGraph.Types.Add(integer);
+            intType = new ScalarType(SpecScalarTypes.Int) { IsSpecScalar = true };
+            _fusionGraph.Types.Add(intType);
+        }
+
+        if (!_fusionGraph.Types.TryGetType<ScalarType>(SpecScalarTypes.String, out var stringType))
+        {
+            stringType = new ScalarType(SpecScalarTypes.String) { IsSpecScalar = true };
+            _fusionGraph.Types.Add(stringType);
         }
 
         Selection = RegisterScalarType(names.SelectionScalar);
@@ -76,14 +82,11 @@ public FusionTypes(Schema fusionGraph, string? prefix = null, bool prefixSelf =
         Fusion = RegisterFusionDirectiveType(
             names.FusionDirective,
             TypeName,
-            boolean,
-            integer);
-        HttpClient = RegisterHttpDirectiveType(
-            names.HttpDirective,
-            TypeName,
-            Uri);
-        WebSocketClient = RegisterWebSocketDirectiveType(
-            names.WebSocketDirective,
+            booleanType,
+            intType);
+        Transport = RegisterTransportDirectiveType(
+            names.TransportDirective,
+            stringType,
             TypeName,
             Uri);
     }
@@ -114,9 +117,7 @@ public FusionTypes(Schema fusionGraph, string? prefix = null, bool prefixSelf =
 
     public DirectiveType ReEncodeId { get; }
 
-    public DirectiveType HttpClient { get; }
-
-    public DirectiveType WebSocketClient { get; }
+    public DirectiveType Transport { get; }
 
     public DirectiveType Fusion { get; }
 
@@ -144,10 +145,9 @@ private InputObjectType RegisterArgumentDefType(
     private EnumType RegisterResolverKindType(string name)
     {
         var resolverKind = new EnumType(name);
-        resolverKind.Values.Add(new EnumValue(FusionEnumValueNames.Query));
+        resolverKind.Values.Add(new EnumValue(FusionEnumValueNames.Fetch));
         resolverKind.Values.Add(new EnumValue(FusionEnumValueNames.Batch));
-        resolverKind.Values.Add(new EnumValue(FusionEnumValueNames.BatchByKey));
-        resolverKind.Values.Add(new EnumValue(FusionEnumValueNames.Subscription));
+        resolverKind.Values.Add(new EnumValue(FusionEnumValueNames.Subscribe));
         resolverKind.ContextData.Add(WellKnownContextData.IsFusionType, true);
         _fusionGraph.Types.Add(resolverKind);
         return resolverKind;
@@ -237,8 +237,7 @@ public Directive CreateResolverDirective(
             var kindValue = kind switch
             {
                 EntityResolverKind.Batch => FusionEnumValueNames.Batch,
-                EntityResolverKind.BatchWithKey => FusionEnumValueNames.BatchByKey,
-                EntityResolverKind.Subscription => FusionEnumValueNames.Subscription,
+                EntityResolverKind.Subscribe => FusionEnumValueNames.Subscribe,
                 _ => throw new NotSupportedException()
             };
 
@@ -256,12 +255,11 @@ private DirectiveType RegisterResolverDirectiveType(
         EnumType resolverKind)
     {
         var directiveType = new DirectiveType(name);
+        directiveType.Locations |= DirectiveLocation.Object;
         directiveType.Arguments.Add(new InputField(SelectArg, new NonNullType(selectionSet)));
         directiveType.Arguments.Add(new InputField(SubgraphArg, new NonNullType(typeName)));
-        directiveType.Arguments.Add(
-            new InputField(ArgumentsArg, new ListType(new NonNullType(argumentDef))));
+        directiveType.Arguments.Add(new InputField(ArgumentsArg, new ListType(new NonNullType(argumentDef))));
         directiveType.Arguments.Add(new InputField(KindArg, resolverKind));
-        directiveType.Locations |= DirectiveLocation.Object;
         directiveType.ContextData.Add(WellKnownContextData.IsFusionType, true);
         _fusionGraph.DirectiveTypes.Add(directiveType);
         return directiveType;
@@ -279,11 +277,25 @@ public Directive CreateSourceDirective(string subgraphName, string? originalName
 
     private DirectiveType RegisterSourceDirectiveType(string name, ScalarType typeName)
     {
-        var directiveType = new DirectiveType(name);
-        directiveType.Locations = DirectiveLocation.FieldDefinition;
-        directiveType.Arguments.Add(new InputField(SubgraphArg, new NonNullType(typeName)));
-        directiveType.Arguments.Add(new InputField(NameArg, typeName));
-        directiveType.ContextData.Add(WellKnownContextData.IsFusionType, true);
+        var directiveType = new DirectiveType(name)
+        {
+            Locations = DirectiveLocation.Object |
+                DirectiveLocation.FieldDefinition |
+                DirectiveLocation.Enum |
+                DirectiveLocation.EnumValue |
+                DirectiveLocation.InputObject |
+                DirectiveLocation.InputFieldDefinition |
+                DirectiveLocation.Scalar,
+            Arguments =
+            {
+                new InputField(SubgraphArg, new NonNullType(typeName)),
+                new InputField(NameArg, typeName)
+            },
+            ContextData =
+            {
+                [WellKnownContextData.IsFusionType] = true
+            }
+        };
         _fusionGraph.DirectiveTypes.Add(directiveType);
         return directiveType;
     }
@@ -310,59 +322,50 @@ private DirectiveType RegisterNodeDirectiveType(string name, ScalarType typeName
         return directiveType;
     }
 
-    public Directive CreateHttpDirective(string subgraphName, string? clientName, Uri baseAddress)
+    public Directive CreateHttpDirective(string subgraphName, string? clientName, Uri location)
         =>  clientName is null 
             ? new Directive(
-                HttpClient,
+                Transport,
                 new Argument(SubgraphArg, subgraphName),
-                new Argument(BaseAddressArg, baseAddress.ToString()))
+                new Argument(LocationArg, location.ToString()),
+                new Argument(KindArg, "HTTP"))
             : new Directive(
-                HttpClient,
+                Transport,
                 new Argument(SubgraphArg, subgraphName),
-                new Argument(ClientNameArg, clientName),
-                new Argument(BaseAddressArg, baseAddress.ToString()));
+                new Argument(ClientGroupArg, clientName),
+                new Argument(LocationArg, location.ToString()),
+                new Argument(KindArg, "HTTP"));
 
-    private DirectiveType RegisterHttpDirectiveType(
+    private DirectiveType RegisterTransportDirectiveType(
         string name,
+        ScalarType stringType,
         ScalarType typeName,
         ScalarType uri)
     {
         var directiveType = new DirectiveType(name);
         directiveType.Locations = DirectiveLocation.FieldDefinition;
         directiveType.Arguments.Add(new InputField(SubgraphArg, new NonNullType(typeName)));
-        directiveType.Arguments.Add(new InputField(ClientNameArg, typeName));
-        directiveType.Arguments.Add(new InputField(BaseAddressArg, uri));
+        directiveType.Arguments.Add(new InputField(ClientGroupArg, typeName));
+        directiveType.Arguments.Add(new InputField(LocationArg, uri));
+        directiveType.Arguments.Add(new InputField(KindArg, new NonNullType(stringType)));
         directiveType.ContextData.Add(WellKnownContextData.IsFusionType, true);
         _fusionGraph.DirectiveTypes.Add(directiveType);
         return directiveType;
     }
 
-    public Directive CreateWebSocketDirective(string subgraphName, string? clientName, Uri baseAddress)
+    public Directive CreateWebSocketDirective(string subgraphName, string? clientName, Uri location)
         =>  clientName is null 
             ? new Directive(
-                WebSocketClient,
+                Transport,
                 new Argument(SubgraphArg, subgraphName),
-                new Argument(BaseAddressArg, baseAddress.ToString()))
+                new Argument(LocationArg, location.ToString()),
+                new Argument(KindArg, "WebSocket"))
             : new Directive(
-                WebSocketClient,
+                Transport,
                 new Argument(SubgraphArg, subgraphName),
-                new Argument(ClientNameArg, clientName),
-                new Argument(BaseAddressArg, baseAddress.ToString()));
-
-    private DirectiveType RegisterWebSocketDirectiveType(
-        string name,
-        ScalarType typeName,
-        ScalarType uri)
-    {
-        var directiveType = new DirectiveType(name);
-        directiveType.Locations = DirectiveLocation.FieldDefinition;
-        directiveType.Arguments.Add(new InputField(SubgraphArg, new NonNullType(typeName)));
-        directiveType.Arguments.Add(new InputField(ClientNameArg, typeName));
-        directiveType.Arguments.Add(new InputField(BaseAddressArg, uri));
-        directiveType.ContextData.Add(WellKnownContextData.IsFusionType, true);
-        _fusionGraph.DirectiveTypes.Add(directiveType);
-        return directiveType;
-    }
+                new Argument(ClientGroupArg, clientName),
+                new Argument(LocationArg, location.ToString()),
+                new Argument(KindArg, "WebSocket"));
 
     private DirectiveType RegisterFusionDirectiveType(
         string name,

src/HotChocolate/Fusion/src/Composition/Pipeline/Enrichers/NodeEntityEnricher.cs

@@ -142,7 +142,7 @@ private static void ResolveWithNodes(
 
         // Create a new EntityResolver for the entity
         var resolver = new EntityResolver(
-            EntityResolverKind.BatchWithKey,
+            EntityResolverKind.Batch,
             selectionSet,
             sourceType.Name,
             sourceSchema.Name);

src/HotChocolate/Fusion/src/Composition/Pipeline/Enrichers/PatternEntityEnricher.cs

@@ -213,7 +213,7 @@ private static void TryRegisterBatchEntityResolver(
 
             // Create a new EntityResolver for the entity
             var resolver = new EntityResolver(
-                EntityResolverKind.BatchWithKey,
+                EntityResolverKind.Batch,
                 selectionSet,
                 entityType.Name,
                 schema.Name);

src/HotChocolate/Fusion/src/Composition/Pipeline/Enrichers/RefResolverEntityEnricher.cs

@@ -54,7 +54,7 @@ public ValueTask EnrichAsync(
 
                         // Create a new EntityResolver for the entity
                         var resolver = new EntityResolver(
-                            EntityResolverKind.BatchWithKey,
+                            EntityResolverKind.Batch,
                             selectionSet,
                             type.Name,
                             schema.Name);
@@ -92,6 +92,7 @@ private static void TryRegisterEntityResolver(
         if ((entityResolverField.Type == entityType ||
                 (entityResolverField.Type.Kind is TypeKind.NonNull &&
                     entityResolverField.Type.InnerType() == entityType)) &&
+            entityResolverField.Arguments.Count > 0 &&
             entityResolverField.Arguments.All(t => t.ContainsIsDirective()))
         {
             var arguments = new List<ArgumentNode>();

src/HotChocolate/Fusion/src/Composition/Pipeline/MergeSubscriptionTypeMiddleware.cs

@@ -108,7 +108,7 @@ private static Directive CreateResolverDirective(
             subgraphName,
             selectionSet,
             arguments,
-            EntityResolverKind.Subscription);
+            EntityResolverKind.Subscribe);
 
     private static Directive CreateVariableDirective(
         CompositionContext context,