Added '@' prefix when exporting directives in Apollo.

src/HotChocolate/ApolloFederation/src/ApolloFederation/FederationTypeInterceptor.cs

@@ -294,7 +294,7 @@ private void RegisterExportedDirectives()
             var typeReference = _typeInspector.GetTypeRef(exportedDirective);
             if (_typeRegistry.TryGetType(typeReference, out var exportedDirectiveType))
             {
-                composeDirectives.Add(new ComposeDirective(exportedDirectiveType.Type.Name));
+                composeDirectives.Add(new ComposeDirective($"@{exportedDirectiveType.Type.Name}"));
             }
         }
 

src/HotChocolate/ApolloFederation/test/ApolloFederation.Tests/Directives/ComposeDirectiveTests.cs

@@ -10,7 +10,7 @@ namespace HotChocolate.ApolloFederation;
 public class ComposeDirectiveTests
 {
     [Fact]
-    public async Task TestServiceTypeEmptyQueryTypePureCodeFirst()
+    public async Task ExportDirectiveUsingTypeCodeFirst()
     {
         // arrange
         var schema = await new ServiceCollection()
@@ -32,6 +32,29 @@ public async Task TestServiceTypeEmptyQueryTypePureCodeFirst()
             .MatchSnapshot();
     }
 
+    [Fact]
+    public async Task ExportDirectiveUsingNameCodeFirst()
+    {
+        // arrange
+        var schema = await new ServiceCollection()
+            .AddGraphQL()
+            .AddApolloFederation()
+            .AddQueryType()
+            .AddType<Address>()
+            .ExportDirective("@custom")
+            .BuildSchemaAsync();
+
+        var entityType = schema.GetType<ObjectType>(FederationTypeNames.ServiceType_Name);
+        var sdlResolver = entityType.Fields[WellKnownFieldNames.Sdl].Resolver!;
+
+        // act
+        var value = await sdlResolver(TestHelper.CreateResolverContext(schema));
+
+        Utf8GraphQLParser
+            .Parse((string)value!)
+            .MatchSnapshot();
+    }
+
     [Key("field")]
     public class Address
     {

src/HotChocolate/ApolloFederation/test/ApolloFederation.Tests/Directives/__snapshots__/ComposeDirectiveTests.TestServiceTypeEmptyQueryTypePureCodeFirst.graphql → src/HotChocolate/ApolloFederation/test/ApolloFederation.Tests/Directives/__snapshots__/ComposeDirectiveTests.ExportDirectiveUsingNameCodeFirst.graphql

@@ -1,4 +1,4 @@
-schema @composeDirective(name: "custom") @link(url: "https:\/\/specs.apollo.dev\/federation\/v2.6", import: [ "@key", "@tag", "FieldSet", "@composeDirective" ]) @link(url: "https:\/\/specs.custom.dev\/custom\/v1.0", import: [ "@custom" ]) {
+schema @composeDirective(name: "@custom") @link(url: "https:\/\/specs.apollo.dev\/federation\/v2.6", import: [ "@key", "@tag", "FieldSet", "@composeDirective" ]) @link(url: "https:\/\/specs.custom.dev\/custom\/v1.0", import: [ "@custom" ]) {
   query: Query
 }
 

src/HotChocolate/ApolloFederation/test/ApolloFederation.Tests/Directives/__snapshots__/ComposeDirectiveTests.ExportDirectiveUsingTypeCodeFirst.graphql

@@ -0,0 +1,37 @@
+schema @composeDirective(name: "@custom") @link(url: "https:\/\/specs.apollo.dev\/federation\/v2.6", import: [ "@key", "@tag", "FieldSet", "@composeDirective" ]) @link(url: "https:\/\/specs.custom.dev\/custom\/v1.0", import: [ "@custom" ]) {
+  query: Query
+}
+
+type Address @key(fields: "field") {
+  field: String! @custom
+}
+
+type Query {
+  _service: _Service!
+  _entities(representations: [_Any!]!): [_Entity]!
+}
+
+"This type provides a field named sdl: String! which exposes the SDL of the service's schema. This SDL (schema definition language) is a printed version of the service's schema including the annotations of federation directives. This SDL does not include the additions of the federation spec."
+type _Service {
+  sdl: String!
+}
+
+"Union of all types that key directive applied. This information is needed by the Apollo federation gateway."
+union _Entity = Address
+
+"Marks underlying custom directive to be included in the Supergraph schema."
+directive @composeDirective(name: String!) repeatable on SCHEMA
+
+directive @custom on FIELD_DEFINITION
+
+"Used to indicate a combination of fields that can be used to uniquely identify and fetch an object or interface."
+directive @key(fields: FieldSet! resolvable: Boolean = true) repeatable on OBJECT | INTERFACE
+
+"Links definitions within the document to external schemas."
+directive @link("Gets imported specification url." url: String! "Gets optional list of imported element names." import: [String!]) repeatable on SCHEMA
+
+"Scalar representing a set of fields."
+scalar FieldSet
+
+"The _Any scalar is used to pass representations of entities from external services into the root _entities field for execution. Validation of the _Any scalar is done by matching the __typename and @external fields defined in the schema."
+scalar _Any