Fixed node field projections when nothing is selected. (#7554)

Author: michaelstaib

src/HotChocolate/Core/src/Execution/Projections/SelectionExpressionBuilder.cs

@@ -54,7 +54,7 @@ public Expression<Func<TRoot, TRoot>> BuildNodeExpression<TRoot>(ISelection sele
 
         if (typeNode.Nodes.Count == 0)
         {
-            TryAddAnyLeafField(selection, typeNode);
+            TryAddAnyLeafField(typeNode, entityType);
         }
 
         CollectTypes(context, selection, root);
@@ -89,7 +89,7 @@ private void CollectTypes(Context context, ISelection selection, TypeContainer p
 
                 if (possibleTypeNode.Nodes.Count == 0)
                 {
-                    TryAddAnyLeafField(selection, possibleTypeNode);
+                    TryAddAnyLeafField(possibleTypeNode, possibleType);
                 }
             }
 
@@ -104,7 +104,7 @@ private void CollectTypes(Context context, ISelection selection, TypeContainer p
 
         if (typeNode.Nodes.Count == 0)
         {
-            TryAddAnyLeafField(selection, typeNode);
+            TryAddAnyLeafField(typeNode, objectType);
         }
     }
 
@@ -200,22 +200,21 @@ private void CollectSelection(
     }
 
     private static void TryAddAnyLeafField(
-        ISelection selection,
-        TypeNode parent)
+        TypeNode parent,
+        IObjectType selectionType)
     {
         // if we could not collect anything it means that either all fields
         // are skipped or that __typename is the only field that is selected.
         // in this case we will try to select the id field or if that does
         // not exist we will look for a leaf field that we can select.
-        var type = (ObjectType)selection.Type.NamedType();
-        if (type.Fields.TryGetField("id", out var idField)
+        if (selectionType.Fields.TryGetField("id", out var idField)
             && idField.Member is PropertyInfo idProperty)
         {
             parent.AddOrGetNode(idProperty);
         }
         else
         {
-            var anyProperty = type.Fields.FirstOrDefault(t => t.Type.IsLeafType() && t.Member is PropertyInfo);
+            var anyProperty = selectionType.Fields.FirstOrDefault(t => t.Type.IsLeafType() && t.Member is PropertyInfo);
             if (anyProperty?.Member is PropertyInfo anyPropertyInfo)
             {
                 parent.AddOrGetNode(anyPropertyInfo);

src/HotChocolate/Core/test/Execution.Tests/Projections/ProjectableDataLoaderTests.cs

@@ -5,6 +5,7 @@
 using HotChocolate.Execution.Processing;
 using HotChocolate.Execution.TestContext;
 using HotChocolate.Types;
+using HotChocolate.Types.Relay;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.DependencyInjection;
 using Squadron;
@@ -595,6 +596,108 @@ public async Task Brand_Only_TypeName()
             .MatchMarkdownSnapshot();
     }
 
+
+    [Fact]
+    public async Task Brand_With_Id_And_Name_Over_Node()
+    {
+        // Arrange
+        var queries = new List<string>();
+        var connectionString = CreateConnectionString();
+        await CatalogContext.SeedAsync(connectionString);
+
+        // Act
+        var result = await new ServiceCollection()
+            .AddScoped(_ => queries)
+            .AddTransient(_ => new CatalogContext(connectionString))
+            .AddGraphQL()
+            .AddQueryType<NodeQuery>()
+            .AddGlobalObjectIdentification()
+            .AddPagingArguments()
+            .ModifyRequestOptions(o => o.IncludeExceptionDetails = true)
+            .ExecuteRequestAsync(
+                """
+                {
+                    node(id: "QnJhbmQ6MQ==") {
+                        id
+                        ... on Brand {
+                            name
+                        }
+                    }
+                }
+                """);
+
+        Snapshot.Create()
+            .AddSql(queries)
+            .AddResult(result)
+            .MatchMarkdownSnapshot();
+    }
+
+    [Fact]
+    public async Task Brand_With_Name_Over_Node()
+    {
+        // Arrange
+        var queries = new List<string>();
+        var connectionString = CreateConnectionString();
+        await CatalogContext.SeedAsync(connectionString);
+
+        // Act
+        var result = await new ServiceCollection()
+            .AddScoped(_ => queries)
+            .AddTransient(_ => new CatalogContext(connectionString))
+            .AddGraphQL()
+            .AddQueryType<NodeQuery>()
+            .AddGlobalObjectIdentification()
+            .AddPagingArguments()
+            .ModifyRequestOptions(o => o.IncludeExceptionDetails = true)
+            .ExecuteRequestAsync(
+                """
+                {
+                    node(id: "QnJhbmQ6MQ==") {
+                        ... on Brand {
+                            name
+                        }
+                    }
+                }
+                """);
+
+        Snapshot.Create()
+            .AddSql(queries)
+            .AddResult(result)
+            .MatchMarkdownSnapshot();
+    }
+
+    [Fact]
+    public async Task Brand_With_Default_Field_Over_Node()
+    {
+        // Arrange
+        var queries = new List<string>();
+        var connectionString = CreateConnectionString();
+        await CatalogContext.SeedAsync(connectionString);
+
+        // Act
+        var result = await new ServiceCollection()
+            .AddScoped(_ => queries)
+            .AddTransient(_ => new CatalogContext(connectionString))
+            .AddGraphQL()
+            .AddQueryType<NodeQuery>()
+            .AddGlobalObjectIdentification()
+            .AddPagingArguments()
+            .ModifyRequestOptions(o => o.IncludeExceptionDetails = true)
+            .ExecuteRequestAsync(
+                """
+                {
+                    node(id: "QnJhbmQ6MQ==") {
+                        __typename
+                    }
+                }
+                """);
+
+        Snapshot.Create()
+            .AddSql(queries)
+            .AddResult(result)
+            .MatchMarkdownSnapshot();
+    }
+
     public class Query
     {
         public async Task<Brand?> GetBrandByIdAsync(
@@ -639,6 +742,17 @@ public class Query
             => await brandById.Select(default(Expression<Func<Brand, Brand>>)).LoadAsync(id, cancellationToken);
     }
 
+    public class NodeQuery
+    {
+        [NodeResolver]
+        public async Task<Brand?> GetBrandByIdAsync(
+            int id,
+            ISelection selection,
+            BrandByIdDataLoader brandById,
+            CancellationToken cancellationToken)
+            => await brandById.Select(selection).LoadAsync(id, cancellationToken);
+    }
+
     [ExtendObjectType<Brand>]
     public class BrandExtensions
     {

src/HotChocolate/Core/test/Execution.Tests/Projections/__snapshots__/ProjectableDataLoaderTests.Brand_With_Default_Field_Over_Node.md

@@ -0,0 +1,23 @@
+# Brand_With_Default_Field_Over_Node
+
+## SQL
+
+```text
+-- @__keys_0={ '1' } (DbType = Object)
+SELECT b."Id"
+FROM "Brands" AS b
+WHERE b."Id" = ANY (@__keys_0)
+```
+
+## Result
+
+```json
+{
+  "data": {
+    "node": {
+      "__typename": "Brand"
+    }
+  }
+}
+```
+

src/HotChocolate/Core/test/Execution.Tests/Projections/__snapshots__/ProjectableDataLoaderTests.Brand_With_Id_And_Name_Over_Node.md

@@ -0,0 +1,24 @@
+# Brand_With_Id_And_Name_Over_Node
+
+## SQL
+
+```text
+-- @__keys_0={ '1' } (DbType = Object)
+SELECT b."Id", b."Name"
+FROM "Brands" AS b
+WHERE b."Id" = ANY (@__keys_0)
+```
+
+## Result
+
+```json
+{
+  "data": {
+    "node": {
+      "id": "QnJhbmQ6MQ==",
+      "name": "Brand0"
+    }
+  }
+}
+```
+

src/HotChocolate/Core/test/Execution.Tests/Projections/__snapshots__/ProjectableDataLoaderTests.Brand_With_Name_Over_Node.md

@@ -4,7 +4,7 @@
 
 ```text
 -- @__keys_0={ '1' } (DbType = Object)
-SELECT b."Id", b."Name"
+SELECT b."Name", b."Id"
 FROM "Brands" AS b
 WHERE b."Id" = ANY (@__keys_0)
 ```
@@ -15,7 +15,6 @@ WHERE b."Id" = ANY (@__keys_0)
 {
   "data": {
     "node": {
-      "id": "QnJhbmQ6MQ==",
       "name": "Brand0"
     }
   }