[release/6.0] Emit diagnostics & exceptions for sourcegen handling init-only properties & JsonInclude attributes

src/libraries/System.Text.Json/gen/JsonSourceGenerator.Emitter.ExceptionMessages.cs

@@ -0,0 +1,36 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace System.Text.Json.SourceGeneration
+{
+    public sealed partial class JsonSourceGenerator
+    {
+        private sealed partial class Emitter
+        {
+            /// <summary>
+            /// Unlike sourcegen warnings, exception messages should not be localized so we keep them in source.
+            /// </summary>
+            private static class ExceptionMessages
+            {
+                public const string InaccessibleJsonIncludePropertiesNotSupported =
+                    "The member '{0}.{1}' has been annotated with the JsonIncludeAttribute but is not visible to the source generator.";
+
+                public const string IncompatibleConverterType =
+                    "The converter '{0}' is not compatible with the type '{1}'.";
+
+                public const string InitOnlyPropertyDeserializationNotSupported =
+                    "Deserialization of init-only properties is currently not supported in source generation mode.";
+
+                public const string InvalidJsonConverterFactoryOutput =
+                    "The converter '{0}' cannot return null or a JsonConverterFactory instance.";
+
+                public const string InvalidSerializablePropertyConfiguration =
+                    "Invalid serializable-property configuration specified for type '{0}'. For more information, see 'JsonSourceGenerationMode.Serialization'.";
+            };
+        }
+    }
+}

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

@@ -324,7 +324,7 @@ private string GenerateForTypeWithUnknownConverter(TypeGenerationSpec typeMetada
                             }}
                             else
                             {{
-                                throw new {InvalidOperationExceptionTypeRef}($""The converter '{{converter.GetType()}}' is not compatible with the type '{{typeToConvert}}'."");
+                                throw new {InvalidOperationExceptionTypeRef}(string.Format(""{ExceptionMessages.IncompatibleConverterType}"", converter.GetType(), typeToConvert));
                             }}
                         }}");
                 }
@@ -333,7 +333,7 @@ private string GenerateForTypeWithUnknownConverter(TypeGenerationSpec typeMetada
                     metadataInitSource.Append($@"
                         if (!converter.CanConvert(typeToConvert))
                         {{
-                            throw new {InvalidOperationExceptionTypeRef}($""The converter '{{converter.GetType()}}' is not compatible with the type '{{typeToConvert}}'."");
+                            throw new {InvalidOperationExceptionTypeRef}(string.Format(""{ExceptionMessages.IncompatibleConverterType}"", converter.GetType(), typeToConvert));
                         }}");
                 }
 
@@ -711,25 +711,28 @@ private string GeneratePropMetadataInitFunc(TypeGenerationSpec typeGenerationSpe
                         ? @$"jsonPropertyName: ""{memberMetadata.JsonPropertyName}"""
                         : "jsonPropertyName: null";
 
-                    string getterNamedArg = memberMetadata.CanUseGetter &&
-                        memberMetadata.DefaultIgnoreCondition != JsonIgnoreCondition.Always
-                        ? $"getter: static (obj) => (({declaringTypeCompilableName})obj).{clrPropertyName}"
-                        : "getter: null";
-
-                    string setterNamedArg;
-                    if (memberMetadata.CanUseSetter &&
-                        memberMetadata.DefaultIgnoreCondition != JsonIgnoreCondition.Always)
+                    string getterNamedArg = memberMetadata switch
                     {
-                        string propMutation = typeGenerationSpec.IsValueType
-                            ? @$"{UnsafeTypeRef}.Unbox<{declaringTypeCompilableName}>(obj).{clrPropertyName} = value!"
-                            : $@"(({declaringTypeCompilableName})obj).{clrPropertyName} = value!";
-
-                        setterNamedArg = $"setter: static (obj, value) => {propMutation}";
-                    }
-                    else
+                        { DefaultIgnoreCondition: JsonIgnoreCondition.Always } => "getter: null",
+                        { CanUseGetter: true } => $"getter: static (obj) => (({declaringTypeCompilableName})obj).{clrPropertyName}",
+                        { CanUseGetter: false, HasJsonInclude: true }
+                            => @$"getter: static (obj) => throw new {InvalidOperationExceptionTypeRef}(""{string.Format(ExceptionMessages.InaccessibleJsonIncludePropertiesNotSupported, typeGenerationSpec.Type.Name, memberMetadata.ClrName)}"")",
+                        _ => "getter: null"
+                    };
+
+                    string setterNamedArg = memberMetadata switch
                     {
-                        setterNamedArg = "setter: null";
-                    }
+                        { DefaultIgnoreCondition: JsonIgnoreCondition.Always } => "setter: null",
+                        { CanUseSetter: true, IsInitOnlySetter: true }
+                            => @$"setter: static (obj, value) => throw new {InvalidOperationExceptionTypeRef}(""{ExceptionMessages.InitOnlyPropertyDeserializationNotSupported}"")",
+                        { CanUseSetter: true } when typeGenerationSpec.IsValueType
+                            => $@"setter: static (obj, value) => {UnsafeTypeRef}.Unbox<{declaringTypeCompilableName}>(obj).{clrPropertyName} = value!",
+                        { CanUseSetter: true }
+                            => @$"setter: static (obj, value) => (({declaringTypeCompilableName})obj).{clrPropertyName} = value!",
+                        { CanUseSetter: false, HasJsonInclude: true }
+                            => @$"setter: static (obj, value) => throw new {InvalidOperationExceptionTypeRef}(""{string.Format(ExceptionMessages.InaccessibleJsonIncludePropertiesNotSupported, typeGenerationSpec.Type.Name, memberMetadata.ClrName)}"")",
+                        _ => "setter: null",
+                    };
 
                     JsonIgnoreCondition? ignoreCondition = memberMetadata.DefaultIgnoreCondition;
                     string ignoreConditionNamedArg = ignoreCondition.HasValue
@@ -821,12 +824,12 @@ private string GenerateFastPathFuncForObject(TypeGenerationSpec typeGenSpec)
                     out Dictionary<string, PropertyGenerationSpec>? serializableProperties,
                     out bool castingRequiredForProps))
                 {
-                    string exceptionMessage = @$"""Invalid serializable-property configuration specified for type '{typeRef}'. For more information, see 'JsonSourceGenerationMode.Serialization'.""";
+                    string exceptionMessage = string.Format(ExceptionMessages.InvalidSerializablePropertyConfiguration, typeRef);
 
                     return GenerateFastPathFuncForType(
                         serializeMethodName,
                         typeRef,
-                        $@"throw new {InvalidOperationExceptionTypeRef}({exceptionMessage});",
+                        $@"throw new {InvalidOperationExceptionTypeRef}(""{exceptionMessage}"");",
                         canBeNull: false); // Skip null check since we want to throw an exception straightaway.
                 }
 
@@ -1202,7 +1205,7 @@ private string GetFetchLogicForRuntimeSpecifiedCustomConverter()
                 converter = factory.CreateConverter(type, {OptionsInstanceVariableName});
                 if (converter == null || converter is {JsonConverterFactoryTypeRef})
                 {{
-                    throw new {InvalidOperationExceptionTypeRef}($""The converter '{{factory.GetType()}}' cannot return null or a JsonConverterFactory instance."");
+                    throw new {InvalidOperationExceptionTypeRef}(string.Format(""{ExceptionMessages.InvalidJsonConverterFactoryOutput}"", factory.GetType()));
                 }}
             }}
 
@@ -1233,7 +1236,7 @@ private string GetFetchLogicForGetCustomConverter_TypesWithFactories()
     {JsonConverterTypeRef}? converter = factory.CreateConverter(type, {Emitter.OptionsInstanceVariableName});
     if (converter == null || converter is {JsonConverterFactoryTypeRef})
     {{
-        throw new {InvalidOperationExceptionTypeRef}($""The converter '{{factory.GetType()}}' cannot return null or a JsonConverterFactory instance."");
+        throw new {InvalidOperationExceptionTypeRef}(string.Format(""{ExceptionMessages.InvalidJsonConverterFactoryOutput}"", factory.GetType()));
     }}
 
     return converter;

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

@@ -139,6 +139,22 @@ private sealed class Parser
                 defaultSeverity: DiagnosticSeverity.Error,
                 isEnabledByDefault: true);
 
+            private static DiagnosticDescriptor InitOnlyPropertyDeserializationNotSupported { get; } = new DiagnosticDescriptor(
+                id: "SYSLIB1037",
+                title: new LocalizableResourceString(nameof(SR.InitOnlyPropertyDeserializationNotSupportedTitle), SR.ResourceManager, typeof(FxResources.System.Text.Json.SourceGeneration.SR)),
+                messageFormat: new LocalizableResourceString(nameof(SR.InitOnlyPropertyDeserializationNotSupportedFormat), SR.ResourceManager, typeof(FxResources.System.Text.Json.SourceGeneration.SR)),
+                category: JsonConstants.SystemTextJsonSourceGenerationName,
+                defaultSeverity: DiagnosticSeverity.Warning,
+                isEnabledByDefault: true);
+
+            private static DiagnosticDescriptor InaccessibleJsonIncludePropertiesNotSupported { get; } = new DiagnosticDescriptor(
+                id: "SYSLIB1038",
+                title: new LocalizableResourceString(nameof(SR.InaccessibleJsonIncludePropertiesNotSupportedTitle), SR.ResourceManager, typeof(FxResources.System.Text.Json.SourceGeneration.SR)),
+                messageFormat: new LocalizableResourceString(nameof(SR.InaccessibleJsonIncludePropertiesNotSupportedFormat), SR.ResourceManager, typeof(FxResources.System.Text.Json.SourceGeneration.SR)),
+                category: JsonConstants.SystemTextJsonSourceGenerationName,
+                defaultSeverity: DiagnosticSeverity.Warning,
+                isEnabledByDefault: true);
+
             public Parser(Compilation compilation, in JsonSourceGenerationContext sourceGenerationContext)
             {
                 _compilation = compilation;
@@ -624,6 +640,7 @@ private TypeGenerationSpec GetOrAddTypeGenerationSpec(Type type, JsonSourceGener
                 string? converterInstatiationLogic = null;
                 bool implementsIJsonOnSerialized = false;
                 bool implementsIJsonOnSerializing = false;
+                bool hasEncounteredInitOnlyProperties = false;
                 bool hasTypeFactoryConverter = false;
                 bool hasPropertyFactoryConverters = false;
 
@@ -954,6 +971,17 @@ void CacheMemberHelper()
                                     dataExtensionPropGenSpec = GetOrAddTypeGenerationSpec(propType, generationMode);
                                     _implicitlyRegisteredTypes.Add(dataExtensionPropGenSpec);
                                 }
+
+                                if (!hasEncounteredInitOnlyProperties && spec.CanUseSetter && spec.IsInitOnlySetter)
+                                {
+                                    _sourceGenerationContext.ReportDiagnostic(Diagnostic.Create(InitOnlyPropertyDeserializationNotSupported, Location.None, new string[] { type.Name }));
+                                    hasEncounteredInitOnlyProperties = true;
+                                }
+
+                                if (spec.HasJsonInclude && (!spec.CanUseGetter || !spec.CanUseSetter || !spec.IsPublic))
+                                {
+                                    _sourceGenerationContext.ReportDiagnostic(Diagnostic.Create(InaccessibleJsonIncludePropertiesNotSupported, Location.None, new string[] { type.Name, spec.ClrName }));
+                                }
                             }
                         }
 
@@ -1079,7 +1107,8 @@ private PropertyGenerationSpec GetPropertyGenerationSpec(
                     out bool canUseGetter,
                     out bool canUseSetter,
                     out bool getterIsVirtual,
-                    out bool setterIsVirtual);
+                    out bool setterIsVirtual,
+                    out bool setterIsInitOnly);
 
                 string clrName = memberInfo.Name;
                 string runtimePropertyName = DetermineRuntimePropName(clrName, jsonPropertyName, _currentContextNamingPolicy);
@@ -1095,6 +1124,7 @@ private PropertyGenerationSpec GetPropertyGenerationSpec(
                     RuntimePropertyName = runtimePropertyName,
                     PropertyNameVarName = propertyNameVarName,
                     IsReadOnly = isReadOnly,
+                    IsInitOnlySetter = setterIsInitOnly,
                     CanUseGetter = canUseGetter,
                     CanUseSetter = canUseSetter,
                     GetterIsVirtual = getterIsVirtual,
@@ -1227,13 +1257,15 @@ private static void ProcessMember(
                 out bool canUseGetter,
                 out bool canUseSetter,
                 out bool getterIsVirtual,
-                out bool setterIsVirtual)
+                out bool setterIsVirtual,
+                out bool setterIsInitOnly)
             {
                 isPublic = false;
                 canUseGetter = false;
                 canUseSetter = false;
                 getterIsVirtual = false;
                 setterIsVirtual = false;
+                setterIsInitOnly = false;
 
                 switch (memberInfo)
                 {
@@ -1260,15 +1292,16 @@ private static void ProcessMember(
                             if (setMethod != null)
                             {
                                 isReadOnly = false;
+                                setterIsInitOnly = setMethod.IsInitOnly();
 
                                 if (setMethod.IsPublic)
                                 {
                                     isPublic = true;
-                                    canUseSetter = !setMethod.IsInitOnly();
+                                    canUseSetter = true;
                                 }
                                 else if (setMethod.IsAssembly)
                                 {
-                                    canUseSetter = hasJsonInclude && !setMethod.IsInitOnly();
+                                    canUseSetter = hasJsonInclude;
                                 }
 
                                 setterIsVirtual = setMethod.IsVirtual;

src/libraries/System.Text.Json/gen/PropertyGenerationSpec.cs

@@ -16,6 +16,9 @@ internal sealed class PropertyGenerationSpec
         /// </summary>
         public bool IsProperty { get; init; }
 
+        /// <summary>
+        /// If representing a property, returns true if either the getter or setter are public.
+        /// </summary>
         public bool IsPublic { get; init; }
 
         public bool IsVirtual { get; init; }
@@ -39,6 +42,11 @@ internal sealed class PropertyGenerationSpec
         /// </summary>
         public bool IsReadOnly { get; init; }
 
+        /// <summary>
+        /// Whether the property has an init-only set method.
+        /// </summary>
+        public bool IsInitOnlySetter { get; init; }
+
         /// <summary>
         /// Whether the property has a public or internal (only usable when JsonIncludeAttribute is specified)
         /// getter that can be referenced in generated source code.

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

@@ -153,4 +153,16 @@
   <data name="DataExtensionPropertyInvalidTitle" xml:space="preserve">
     <value>Data extension property type invalid.</value>
   </data>
-</root>
+  <data name="InitOnlyPropertyDeserializationNotSupportedTitle" xml:space="preserve">
+    <value>Deserialization of init-only properties is currently not supported in source generation mode.</value>
+  </data>
+  <data name="InitOnlyPropertyDeserializationNotSupportedFormat" xml:space="preserve">
+    <value>The type '{0}' defines init-only properties, deserialization of which is currently not supported in source generation mode.</value>
+  </data>
+  <data name="InaccessibleJsonIncludePropertiesNotSupportedTitle" xml:space="preserve">
+    <value>Inaccessible properties annotated with the JsonIncludeAttribute are not supported in source generation mode.</value>
+  </data>
+  <data name="InaccessibleJsonIncludePropertiesNotSupportedFormat" xml:space="preserve">
+    <value>The member '{0}.{1}' has been annotated with the JsonIncludeAttribute but is not visible to the source generator.</value>
+  </data>
+</root>

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

@@ -32,6 +32,26 @@
         <target state="translated">Duplicitní název typu</target>
         <note />
       </trans-unit>
+      <trans-unit id="InaccessibleJsonIncludePropertiesNotSupportedFormat">
+        <source>The member '{0}.{1}' has been annotated with the JsonIncludeAttribute but is not visible to the source generator.</source>
+        <target state="new">The member '{0}.{1}' has been annotated with the JsonIncludeAttribute but is not visible to the source generator.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="InaccessibleJsonIncludePropertiesNotSupportedTitle">
+        <source>Inaccessible properties annotated with the JsonIncludeAttribute are not supported in source generation mode.</source>
+        <target state="new">Inaccessible properties annotated with the JsonIncludeAttribute are not supported in source generation mode.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="InitOnlyPropertyDeserializationNotSupportedFormat">
+        <source>The type '{0}' defines init-only properties, deserialization of which is currently not supported in source generation mode.</source>
+        <target state="new">The type '{0}' defines init-only properties, deserialization of which is currently not supported in source generation mode.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="InitOnlyPropertyDeserializationNotSupportedTitle">
+        <source>Deserialization of init-only properties is currently not supported in source generation mode.</source>
+        <target state="new">Deserialization of init-only properties is currently not supported in source generation mode.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="MultipleJsonConstructorAttributeFormat">
         <source>Type '{0}' has multiple constructors annotated with 'JsonConstructorAttribute'.</source>
         <target state="translated">Typ {0} má více konstruktorů anotovaných s JsonConstructorAttribute. </target>