Fixed result formatting when non-null root field becomes null.

src/CookieCrumble/src/CookieCrumble/Snapshot.cs

@@ -14,7 +14,7 @@
 
 namespace CookieCrumble;
 
-public sealed class Snapshot
+public class Snapshot
 {
     private static readonly object _sync = new();
     private static readonly UTF8Encoding _encoding = new();
@@ -49,6 +49,9 @@ public Snapshot(string? postFix = null, string? extension = null)
 
     public static Snapshot Create(string? postFix = null, string? extension = null)
         => new(postFix, extension);
+
+    public static DisposableSnapshot Start(string? postFix = null, string? extension = null)
+        => new(postFix, extension);
 
     public static void Match(
         object? value,
@@ -474,3 +477,10 @@ public SnapshotSegment(string? name, object? value, ISnapshotValueFormatter form
         public ISnapshotValueFormatter Formatter { get; }
     }
 }
+
+public sealed class DisposableSnapshot(string? postFix = null, string? extension = null)
+    : Snapshot(postFix, extension)
+    , IDisposable
+{
+    public void Dispose() => Match();
+}

src/HotChocolate/AspNetCore/test/AspNetCore.Authorization.Tests/__snapshots__/AuthorizationHandlerTests.Authorize_NoDefaultPolicy.snap

@@ -15,5 +15,6 @@
         "code": "AUTH_NO_DEFAULT_POLICY"
       }
     }
-  ]
+  ],
+  "data": null
 }

src/HotChocolate/AspNetCore/test/AspNetCore.Authorization.Tests/__snapshots__/AuthorizationHandlerTests.Authorize_NotAllowed.snap

@@ -15,5 +15,6 @@
         "code": "AUTH_NOT_AUTHORIZED"
       }
     }
-  ]
+  ],
+  "data": null
 }

src/HotChocolate/AspNetCore/test/AspNetCore.Authorization.Tests/__snapshots__/AuthorizationHandlerTests.Authorize_NotAuthenticated.snap

@@ -15,5 +15,6 @@
         "code": "AUTH_NOT_AUTHENTICATED"
       }
     }
-  ]
+  ],
+  "data": null
 }

src/HotChocolate/AspNetCore/test/AspNetCore.Authorization.Tests/__snapshots__/AuthorizationHandlerTests.Authorize_PolicyNotFound.snap

@@ -15,5 +15,6 @@
         "code": "AUTH_POLICY_NOT_FOUND"
       }
     }
-  ]
+  ],
+  "data": null
 }

src/HotChocolate/AspNetCore/test/AspNetCore.Authorization.Tests/__snapshots__/AuthorizeSchemaTests.AuthorizeOnExtension.snap

@@ -15,5 +15,6 @@
         "code": "AUTH_NOT_AUTHORIZED"
       }
     }
-  ]
+  ],
+  "data": null
 }

src/HotChocolate/Caching/test/Caching.Tests/__snapshots__/HttpCachingTests.MaxAgeAndScope_Should_Cache.snap

@@ -15,5 +15,5 @@
       ]
     }
   ],
-  "Body": "{\"data\":{\"field\":\"\"}}"
+  "Body": "{}"
 }

src/HotChocolate/Caching/test/Caching.Tests/__snapshots__/HttpCachingTests.MaxAge_NonZero_Should_Cache.snap

@@ -15,5 +15,5 @@
       ]
     }
   ],
-  "Body": "{\"data\":{\"field\":\"\"}}"
+  "Body": "{}"
 }

src/HotChocolate/Caching/test/Caching.Tests/__snapshots__/HttpCachingTests.MaxAge_Zero_Should_Cache.snap

@@ -15,5 +15,5 @@
       ]
     }
   ],
-  "Body": "{\"data\":{\"field\":\"\"}}"
+  "Body": "{}"
 }

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

@@ -62,6 +62,12 @@ public interface IQueryResult : IExecutionResult
     /// </summary>
     /// <value></value>
     bool? HasNext { get; }
+
+    /// <summary>
+    /// Specifies if data was explicitly set.
+    /// If <c>false</c> the data was not set (including null).
+    /// </summary>
+    bool IsDataSet { get; }
 
     /// <summary>
     /// Serializes this GraphQL result into a dictionary.

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

@@ -22,7 +22,8 @@
         string? label,
         Path? path,
         bool? hasNext,
-        Func<ValueTask>[] cleanupTasks)
+        Func<ValueTask>[] cleanupTasks,
+        bool isDataSet)
         : base(cleanupTasks)
     {
         if (data is null &&
@@ -45,6 +46,7 @@
         Label = label;
         Path = path;
         HasNext = hasNext;
+        IsDataSet = isDataSet;
     }
 
     /// <summary>
@@ -113,6 +115,9 @@
     /// <inheritdoc />
     public bool? HasNext { get; }
 
+    /// <inheritdoc />
+    public bool IsDataSet { get; }
+
     /// <inheritdoc />
     public IReadOnlyDictionary<string, object?> ToDictionary()
         => QueryResultHelper.ToDictionary(this);

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

@@ -15,12 +15,14 @@ public sealed class QueryResultBuilder : IQueryResultBuilder
     private string? _label;
     private Path? _path;
     private bool? _hasNext;
+    private bool? _isDataSet;
     private Func<ValueTask>[] _cleanupTasks = Array.Empty<Func<ValueTask>>();
 
     public IQueryResultBuilder SetData(IReadOnlyDictionary<string, object?>? data)
     {
         _data = data;
         _items = null;
+        _isDataSet = true;
         return this;
     }
 
@@ -176,7 +178,8 @@ public IQueryResult Create()
             _label,
             _path,
             _hasNext,
-            _cleanupTasks);
+            _cleanupTasks,
+            _isDataSet ?? false);
 
     public static QueryResultBuilder New() => new();
 
@@ -210,6 +213,7 @@ public static QueryResultBuilder FromResult(IQueryResult result)
         builder._label = result.Label;
         builder._path = result.Path;
         builder._hasNext = result.HasNext;
+        builder._isDataSet = result.IsDataSet;
 
         return builder;
     }

src/HotChocolate/Core/src/Execution/Processing/Result/ResultBuilder.cs

@@ -221,7 +221,7 @@ public IQueryResult BuildResult()
             throw new InvalidOperationException(Resources.ResultHelper_BuildResult_InvalidResult);
         }
 
-        if (_errors.Count > 0)
+        if (_errors.Count > 1)
         {
             _errors.Sort(ErrorComparer.Default);
         }
@@ -252,7 +252,8 @@ public IQueryResult BuildResult()
             hasNext: _hasNext,
             cleanupTasks: _cleanupTasks.Count == 0 
                 ? _emptyCleanupTasks 
-                : _cleanupTasks.ToArray());
+                : _cleanupTasks.ToArray(),
+            isDataSet: true);
 
         if (_data is not null)
         {

src/HotChocolate/Core/src/Execution/Serialization/JsonResultFormatter.cs

@@ -244,7 +244,7 @@
         writer.WriteStartObject();
 
         WriteErrors(writer, result.Errors);
-        WriteData(writer, result.Data);
+        WriteData(writer, result);
         WriteItems(writer, result.Items);
         WriteIncremental(writer, result.Incremental);
         WriteExtensions(writer, result.Extensions);
@@ -281,20 +281,28 @@
 
     private void WriteData(
         Utf8JsonWriter writer,
-        IReadOnlyDictionary<string, object?>? data)
+        IQueryResult result)
     {
-        if (data is not null)
+        if (!result.IsDataSet)
         {
-            writer.WritePropertyName(Data);
+            return;
+        }
 
-            if (data is ObjectResult resultMap)
-            {
-                WriteObjectResult(writer, resultMap);
-            }
-            else
-            {
-                WriteDictionary(writer, data);
-            }
+        if (result.Data is null)
+        {
+            writer.WriteNull(Data);
+            return;
+        }
+
+        writer.WritePropertyName(Data);
+
+        if (result.Data is ObjectResult resultMap)
+        {
+            WriteObjectResult(writer, resultMap);
+        }
+        else
+        {
+            WriteDictionary(writer, result.Data);
         }
     }
 

src/HotChocolate/Core/test/Abstractions.Tests/Execution/__snapshots__/QueryResultBuilderTests.Create_Result_Set_Data.snap

@@ -10,5 +10,6 @@
   "Extensions": null,
   "Incremental": null,
   "ContextData": null,
-  "HasNext": null
+  "HasNext": null,
+  "IsDataSet": true
 }

src/HotChocolate/Core/test/Abstractions.Tests/Execution/__snapshots__/QueryResultBuilderTests.Create_Result_Set_Items.snap

@@ -10,5 +10,6 @@
   "Extensions": null,
   "Incremental": null,
   "ContextData": null,
-  "HasNext": null
+  "HasNext": null,
+  "IsDataSet": false
 }

src/HotChocolate/Core/test/Authorization.Tests/AnnotationBasedAuthorizationTests.cs

@@ -897,7 +897,8 @@ public async Task Assert_UserState_Exists()
                         "originalValue": "abc"
                       }
                     }
-                  ]
+                  ],
+                  "data": null
                 }
                 """);
     }