Support type-level JsonIgnoreCondition via [JsonIgnore] on classes, structs, and interfaces

docs/project/list-of-diagnostics.md

@@ -271,7 +271,7 @@ The diagnostic id values reserved for .NET Libraries analyzer warnings are `SYSL
 |  __`SYSLIB1223`__ | Attributes deriving from JsonConverterAttribute are not supported by the source generator. |
 |  __`SYSLIB1224`__ | Types annotated with JsonSerializableAttribute must be classes deriving from JsonSerializerContext. |
 |  __`SYSLIB1225`__ | Type includes ref like property, field or constructor parameter. |
-|  __`SYSLIB1226`__ | _`SYSLIB1220`-`SYSLIB1229` reserved for System.Text.Json.SourceGeneration._ |
+|  __`SYSLIB1226`__ | 'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations. |
 |  __`SYSLIB1227`__ | _`SYSLIB1220`-`SYSLIB1229` reserved for System.Text.Json.SourceGeneration._ |
 |  __`SYSLIB1228`__ | _`SYSLIB1220`-`SYSLIB1229` reserved for System.Text.Json.SourceGeneration._ |
 |  __`SYSLIB1229`__ | _`SYSLIB1220`-`SYSLIB1229` reserved for System.Text.Json.SourceGeneration._ |

src/libraries/System.Text.Json/gen/Helpers/KnownTypeSymbols.cs

@@ -225,6 +225,9 @@ public KnownTypeSymbols(Compilation compilation)
         public INamedTypeSymbol? JsonDerivedTypeAttributeType => GetOrResolveType("System.Text.Json.Serialization.JsonDerivedTypeAttribute", ref _JsonDerivedTypeAttributeType);
         private Option<INamedTypeSymbol?> _JsonDerivedTypeAttributeType;
 
+        public INamedTypeSymbol? JsonIgnoreAttributeType => GetOrResolveType("System.Text.Json.Serialization.JsonIgnoreAttribute", ref _JsonIgnoreAttributeType);
+        private Option<INamedTypeSymbol?> _JsonIgnoreAttributeType;
+
         public INamedTypeSymbol? JsonNumberHandlingAttributeType => GetOrResolveType("System.Text.Json.Serialization.JsonNumberHandlingAttribute", ref _JsonNumberHandlingAttributeType);
         private Option<INamedTypeSymbol?> _JsonNumberHandlingAttributeType;
 

src/libraries/System.Text.Json/gen/JsonSourceGenerator.DiagnosticDescriptors.cs

@@ -131,6 +131,14 @@ internal static class DiagnosticDescriptors
                 category: JsonConstants.SystemTextJsonSourceGenerationName,
                 defaultSeverity: DiagnosticSeverity.Warning,
                 isEnabledByDefault: true);
+
+            public static DiagnosticDescriptor JsonIgnoreConditionAlwaysInvalidOnType { get; } = DiagnosticDescriptorHelper.Create(
+                id: "SYSLIB1226",
+                title: new LocalizableResourceString(nameof(SR.JsonIgnoreConditionAlwaysInvalidOnTypeTitle), SR.ResourceManager, typeof(FxResources.System.Text.Json.SourceGeneration.SR)),
+                messageFormat: new LocalizableResourceString(nameof(SR.JsonIgnoreConditionAlwaysInvalidOnTypeFormat), SR.ResourceManager, typeof(FxResources.System.Text.Json.SourceGeneration.SR)),
+                category: JsonConstants.SystemTextJsonSourceGenerationName,
+                defaultSeverity: DiagnosticSeverity.Warning,
+                isEnabledByDefault: true);
         }
     }
 }

src/libraries/System.Text.Json/gen/JsonSourceGenerator.Parser.cs

@@ -587,6 +587,7 @@ private TypeGenerationSpec ParseTypeGenerationSpec(in TypeToGenerate typeToGener
                     out JsonNumberHandling? numberHandling,
                     out JsonUnmappedMemberHandling? unmappedMemberHandling,
                     out JsonObjectCreationHandling? preferredPropertyObjectCreationHandling,
+                    out JsonIgnoreCondition? typeIgnoreCondition,
                     out bool foundJsonConverterAttribute,
                     out TypeRef? customConverterType,
                     out bool isPolymorphic);
@@ -691,7 +692,7 @@ private TypeGenerationSpec ParseTypeGenerationSpec(in TypeToGenerate typeToGener
                     implementsIJsonOnSerialized = _knownSymbols.IJsonOnSerializedType.IsAssignableFrom(type);
 
                     ctorParamSpecs = ParseConstructorParameters(typeToGenerate, constructor, out constructionStrategy, out constructorSetsRequiredMembers);
-                    propertySpecs = ParsePropertyGenerationSpecs(contextType, typeToGenerate, options, out hasExtensionDataProperty, out fastPathPropertyIndices);
+                    propertySpecs = ParsePropertyGenerationSpecs(contextType, typeToGenerate, typeIgnoreCondition, options, out hasExtensionDataProperty, out fastPathPropertyIndices);
                     propertyInitializerSpecs = ParsePropertyInitializers(ctorParamSpecs, propertySpecs, constructorSetsRequiredMembers, ref constructionStrategy);
                 }
 
@@ -748,13 +749,15 @@ private void ProcessTypeCustomAttributes(
                 out JsonNumberHandling? numberHandling,
                 out JsonUnmappedMemberHandling? unmappedMemberHandling,
                 out JsonObjectCreationHandling? objectCreationHandling,
+                out JsonIgnoreCondition? typeIgnoreCondition,
                 out bool foundJsonConverterAttribute,
                 out TypeRef? customConverterType,
                 out bool isPolymorphic)
             {
                 numberHandling = null;
                 unmappedMemberHandling = null;
                 objectCreationHandling = null;
+                typeIgnoreCondition = null;
                 customConverterType = null;
                 foundJsonConverterAttribute = false;
                 isPolymorphic = false;
@@ -784,6 +787,27 @@ private void ProcessTypeCustomAttributes(
                         foundJsonConverterAttribute = true;
                     }
 
+                    if (SymbolEqualityComparer.Default.Equals(attributeType, _knownSymbols.JsonIgnoreAttributeType))
+                    {
+                        ImmutableArray<KeyValuePair<string, TypedConstant>> namedArgs = attributeData.NamedArguments;
+
+                        if (namedArgs.Length == 0)
+                        {
+                            typeIgnoreCondition = JsonIgnoreCondition.Always;
+                        }
+                        else if (namedArgs.Length == 1 &&
+                            namedArgs[0].Value.Type?.ToDisplayString() == JsonIgnoreConditionFullName)
+                        {
+                            typeIgnoreCondition = (JsonIgnoreCondition)namedArgs[0].Value.Value!;
+                        }
+
+                        if (typeIgnoreCondition == JsonIgnoreCondition.Always)
+                        {
+                            ReportDiagnostic(DiagnosticDescriptors.JsonIgnoreConditionAlwaysInvalidOnType, typeToGenerate.Location, typeToGenerate.Type.ToDisplayString());
+                            typeIgnoreCondition = null; // Reset so it doesn't affect properties
+                        }
+                    }
+
                     if (SymbolEqualityComparer.Default.Equals(attributeType, _knownSymbols.JsonDerivedTypeAttributeType))
                     {
                         Debug.Assert(attributeData.ConstructorArguments.Length > 0);
@@ -978,6 +1002,7 @@ private bool TryResolveCollectionType(
             private List<PropertyGenerationSpec> ParsePropertyGenerationSpecs(
                 INamedTypeSymbol contextType,
                 in TypeToGenerate typeToGenerate,
+                JsonIgnoreCondition? typeIgnoreCondition,
                 SourceGenerationOptionsSpec? options,
                 out bool hasExtensionDataProperty,
                 out List<int>? fastPathPropertyIndices)
@@ -1060,6 +1085,7 @@ void AddMember(
                         typeLocation,
                         memberType,
                         memberInfo,
+                        typeIgnoreCondition,
                         ref hasExtensionDataProperty,
                         generationMode,
                         options);
@@ -1208,6 +1234,7 @@ private bool IsValidDataExtensionPropertyType(ITypeSymbol type)
                 Location? typeLocation,
                 ITypeSymbol memberType,
                 ISymbol memberInfo,
+                JsonIgnoreCondition? typeIgnoreCondition,
                 ref bool typeHasExtensionDataProperty,
                 JsonSourceGenerationMode? generationMode,
                 SourceGenerationOptionsSpec? options)
@@ -1227,6 +1254,16 @@ private bool IsValidDataExtensionPropertyType(ITypeSymbol type)
                     out bool isExtensionData,
                     out bool hasJsonRequiredAttribute);
 
+                // Fall back to the type-level [JsonIgnore] if no member-level attribute is specified.
+                // WhenWritingNull is invalid for non-nullable value types; treat as Never in that case
+                // so that the type-level annotation still overrides the global JSO DefaultIgnoreCondition.
+                if (ignoreCondition is null && typeIgnoreCondition is not null)
+                {
+                    ignoreCondition = typeIgnoreCondition == JsonIgnoreCondition.WhenWritingNull && !memberType.IsNullableType()
+                        ? JsonIgnoreCondition.Never
+                        : typeIgnoreCondition;
+                }
+
                 ProcessMember(
                     contextType,
                     memberInfo,

src/libraries/System.Text.Json/gen/Resources/Strings.resx

@@ -213,4 +213,10 @@
   <data name="TypeContainsRefLikeMemberFormat" xml:space="preserve">
     <value>The type '{0}' includes the ref like property, field or constructor parameter '{1}'. No source code will be generated for the property, field or constructor.</value>
   </data>
+  <data name="JsonIgnoreConditionAlwaysInvalidOnTypeTitle" xml:space="preserve">
+    <value>'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</value>
+  </data>
+  <data name="JsonIgnoreConditionAlwaysInvalidOnTypeFormat" xml:space="preserve">
+    <value>The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</value>
+  </data>
 </root>

src/libraries/System.Text.Json/gen/Resources/xlf/Strings.cs.xlf

@@ -92,6 +92,16 @@
         <target state="translated">JsonConverterAttribute.Type obsahuje neplatný nebo nepřístupný argument.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonIgnoreConditionAlwaysInvalidOnTypeFormat">
+        <source>The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</source>
+        <target state="new">The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonIgnoreConditionAlwaysInvalidOnTypeTitle">
+        <source>'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</source>
+        <target state="new">'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="JsonSerializableAttributeOnNonContextTypeMessageFormat">
         <source>The type '{0}' has been annotated with JsonSerializableAttribute but does not derive from JsonSerializerContext. No source code will be generated.</source>
         <target state="translated">Typ „{0}“ byl anotován atributem JsonSerializableAttribute, ale není odvozen od třídy JsonSerializerContext. Nebude vygenerován žádný zdrojový kód.</target>

src/libraries/System.Text.Json/gen/Resources/xlf/Strings.de.xlf

@@ -92,6 +92,16 @@
         <target state="translated">"JsonConverterAttribute.Type" enthält ein ungültiges oder nicht zugängliches Argument.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonIgnoreConditionAlwaysInvalidOnTypeFormat">
+        <source>The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</source>
+        <target state="new">The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonIgnoreConditionAlwaysInvalidOnTypeTitle">
+        <source>'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</source>
+        <target state="new">'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="JsonSerializableAttributeOnNonContextTypeMessageFormat">
         <source>The type '{0}' has been annotated with JsonSerializableAttribute but does not derive from JsonSerializerContext. No source code will be generated.</source>
         <target state="translated">Der Typ "{0}" wurde mit JsonSerializableAttribute kommentiert, ist aber nicht von JsonSerializerContext abgeleitet. Es wird kein Quellcode generiert.</target>

src/libraries/System.Text.Json/gen/Resources/xlf/Strings.es.xlf

@@ -92,6 +92,16 @@
         <target state="translated">“JsonConverterAttribute.Type” contiene un argumento no válido o inaccesible.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonIgnoreConditionAlwaysInvalidOnTypeFormat">
+        <source>The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</source>
+        <target state="new">The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonIgnoreConditionAlwaysInvalidOnTypeTitle">
+        <source>'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</source>
+        <target state="new">'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="JsonSerializableAttributeOnNonContextTypeMessageFormat">
         <source>The type '{0}' has been annotated with JsonSerializableAttribute but does not derive from JsonSerializerContext. No source code will be generated.</source>
         <target state="translated">El tipo "{0}" se ha anotado con JsonSerializableAttribute, pero no se deriva de JsonSerializerContext. No se generará ningún código fuente.</target>

src/libraries/System.Text.Json/gen/Resources/xlf/Strings.fr.xlf

@@ -92,6 +92,16 @@
         <target state="translated">'JsonConverterAttribute.Type' contient un argument non valide ou inaccessible.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonIgnoreConditionAlwaysInvalidOnTypeFormat">
+        <source>The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</source>
+        <target state="new">The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonIgnoreConditionAlwaysInvalidOnTypeTitle">
+        <source>'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</source>
+        <target state="new">'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="JsonSerializableAttributeOnNonContextTypeMessageFormat">
         <source>The type '{0}' has been annotated with JsonSerializableAttribute but does not derive from JsonSerializerContext. No source code will be generated.</source>
         <target state="translated">Le type '{0}' a été annoté avec l'attribut JsonSerializable mais ne dérive pas de JsonSerializerContext. Aucun code source ne sera généré.</target>

src/libraries/System.Text.Json/gen/Resources/xlf/Strings.it.xlf

@@ -92,6 +92,16 @@
         <target state="translated">'JsonConverterAttribute.Type' contiene un argomento non valido o inaccessibile.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonIgnoreConditionAlwaysInvalidOnTypeFormat">
+        <source>The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</source>
+        <target state="new">The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonIgnoreConditionAlwaysInvalidOnTypeTitle">
+        <source>'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</source>
+        <target state="new">'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="JsonSerializableAttributeOnNonContextTypeMessageFormat">
         <source>The type '{0}' has been annotated with JsonSerializableAttribute but does not derive from JsonSerializerContext. No source code will be generated.</source>
         <target state="translated">Il tipo '{0}' è stato annotato con JsonSerializableAttribute ma non deriva da JsonSerializerContext. Non verrà generato alcun codice sorgente.</target>

src/libraries/System.Text.Json/gen/Resources/xlf/Strings.ja.xlf

@@ -92,6 +92,16 @@
         <target state="translated">'JsonConverterAttribute.Type' に無効な、またはアクセスできない引数が含まれています。</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonIgnoreConditionAlwaysInvalidOnTypeFormat">
+        <source>The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</source>
+        <target state="new">The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonIgnoreConditionAlwaysInvalidOnTypeTitle">
+        <source>'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</source>
+        <target state="new">'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="JsonSerializableAttributeOnNonContextTypeMessageFormat">
         <source>The type '{0}' has been annotated with JsonSerializableAttribute but does not derive from JsonSerializerContext. No source code will be generated.</source>
         <target state="translated">型 '{0}' は JsonSerializableAttribute で注釈が付けられていますが、JsonSerializerContext から派生したものではありません。ソース コードは生成されません。</target>

src/libraries/System.Text.Json/gen/Resources/xlf/Strings.ko.xlf

@@ -92,6 +92,16 @@
         <target state="translated">'JsonConverterAttribute.Type'에 잘못되었거나 액세스할 수 없는 인수가 포함되어 있습니다.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonIgnoreConditionAlwaysInvalidOnTypeFormat">
+        <source>The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</source>
+        <target state="new">The type '{0}' has been annotated with 'JsonIgnoreAttribute' using 'JsonIgnoreCondition.Always' which is not valid on type declarations. The attribute will be ignored.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonIgnoreConditionAlwaysInvalidOnTypeTitle">
+        <source>'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</source>
+        <target state="new">'JsonIgnoreCondition.Always' is not valid on type-level 'JsonIgnoreAttribute' annotations.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="JsonSerializableAttributeOnNonContextTypeMessageFormat">
         <source>The type '{0}' has been annotated with JsonSerializableAttribute but does not derive from JsonSerializerContext. No source code will be generated.</source>
         <target state="translated">'{0}' 형식에 JsonSerializableAttribute 주석이 추가되었지만 JsonSerializerContext에서 파생되지 않았습니다. 소스 코드가 생성되지 않습니다.</target>