Use NullabilityInfoContext for nullability information

Author: maurei

src/JsonApiDotNetCore.OpenApi/MemberInfoExtensions.cs

@@ -1,21 +1,40 @@
 using System.ComponentModel.DataAnnotations;
+using System.Reflection;
 using JsonApiDotNetCore.Resources.Annotations;
 using Swashbuckle.AspNetCore.SwaggerGen;
 
 namespace JsonApiDotNetCore.OpenApi;
 
 internal static class ResourceFieldAttributeExtensions
 {
+    private static readonly NullabilityInfoContext NullabilityInfoContext = new();
+
     public static bool IsNullable(this ResourceFieldAttribute source)
     {
-        TypeCategory fieldTypeCategory = source.Property.GetTypeCategory();
         bool hasRequiredAttribute = source.Property.HasAttribute<RequiredAttribute>();
 
-        return fieldTypeCategory switch
+        if (hasRequiredAttribute)
         {
-            TypeCategory.NonNullableReferenceType or TypeCategory.ValueType => false,
-            TypeCategory.NullableReferenceType or TypeCategory.NullableValueType => !hasRequiredAttribute,
-            _ => throw new UnreachableCodeException()
-        };
+            // Reflects the following cases, independent of NRT setting
+            //      `[Required] int? Number` => not nullable
+            //      `[Required] int Number` => not nullable
+            //      `[Required] string Text` => not nullable
+            //      `[Required] string? Text` => not nullable
+            //      `[Required] string Text` => not nullable
+            return false;
+        }
+
+        NullabilityInfo nullabilityInfo = NullabilityInfoContext.Create(source.Property);
+
+        //  Reflects the following cases:
+        //    Independent of NRT:
+        //      `int? Number` => nullable
+        //      `int Number` => not nullable
+        //    If NRT is enabled:
+        //      `string? Text` => nullable
+        //      `string Text` => not nullable
+        //    If NRT is disabled:
+        //      `string Text` => nullable
+        return nullabilityInfo.ReadState is not NullabilityState.NotNull;
     }
 }

src/JsonApiDotNetCore.OpenApi/ResourceFieldAttributeExtensions.cs

@@ -26,6 +26,13 @@ internal sealed class JsonApiSchemaGenerator : ISchemaGenerator
         typeof(NullableToOneRelationshipInRequest<>)
     };
 
+    private static readonly Type[] JsonApiDocumentWithNullableDataOpenTypes =
+    {
+        typeof(NullableSecondaryResourceResponseDocument<>),
+        typeof(NullableResourceIdentifierResponseDocument<>),
+        typeof(NullableToOneRelationshipInRequest<>)
+    };
+
     private readonly ISchemaGenerator _defaultSchemaGenerator;
     private readonly ResourceObjectSchemaGenerator _resourceObjectSchemaGenerator;
     private readonly NullableReferenceSchemaGenerator _nullableReferenceSchemaGenerator;
@@ -58,7 +65,7 @@ public OpenApiSchema GenerateSchema(Type type, SchemaRepository schemaRepository
         {
             OpenApiSchema schema = GenerateJsonApiDocumentSchema(type);
 
-            if (IsDataPropertyNullable(type))
+            if (IsDataPropertyNullableInDocument(type))
             {
                 SetDataObjectSchemaToNullable(schema);
             }
@@ -98,18 +105,11 @@ private static bool IsManyDataDocument(Type documentType)
         return documentType.BaseType!.GetGenericTypeDefinition() == typeof(ManyData<>);
     }
 
-    private static bool IsDataPropertyNullable(Type type)
+    private static bool IsDataPropertyNullableInDocument(Type documentType)
     {
-        PropertyInfo? dataProperty = type.GetProperty(nameof(JsonApiObjectPropertyName.Data));
-
-        if (dataProperty == null)
-        {
-            throw new UnreachableCodeException();
-        }
-
-        TypeCategory typeCategory = dataProperty.GetTypeCategory();
+        Type documentOpenType = documentType.GetGenericTypeDefinition();
 
-        return typeCategory == TypeCategory.NullableReferenceType;
+        return JsonApiDocumentWithNullableDataOpenTypes.Contains(documentOpenType);
     }
 
     private void SetDataObjectSchemaToNullable(OpenApiSchema referenceSchemaForDocument)

src/JsonApiDotNetCore.OpenApi/SwaggerComponents/JsonApiSchemaGenerator.cs

@@ -12,13 +12,21 @@ namespace JsonApiDotNetCore.OpenApi.SwaggerComponents;
 
 internal sealed class ResourceFieldObjectSchemaBuilder
 {
-    private static readonly Type[] RelationshipInResponseOpenTypes =
+    private static readonly NullabilityInfoContext NullabilityInfoContext = new();
+
+    private static readonly Type[] RelationshipSchemaInResponseOpenTypes =
     {
         typeof(ToOneRelationshipInResponse<>),
         typeof(ToManyRelationshipInResponse<>),
         typeof(NullableToOneRelationshipInResponse<>)
     };
 
+    private static readonly Type[] NullableRelationshipSchemaOpenTypes =
+    {
+        typeof(NullableToOneRelationshipInRequest<>),
+        typeof(NullableToOneRelationshipInResponse<>)
+    };
+
     private readonly ResourceTypeInfo _resourceTypeInfo;
     private readonly ISchemaRepositoryAccessor _schemaRepositoryAccessor;
     private readonly SchemaGenerator _defaultSchemaGenerator;
@@ -111,15 +119,14 @@ private bool IsFieldRequired(ResourceFieldAttribute field)
             return false;
         }
 
-        TypeCategory fieldTypeCategory = field.Property.GetTypeCategory();
         bool hasRequiredAttribute = field.Property.HasAttribute<RequiredAttribute>();
 
-        return fieldTypeCategory switch
+        NullabilityInfo nullabilityInfo = NullabilityInfoContext.Create(field.Property);
+
+        return field.Property.PropertyType.IsValueType switch
         {
-            TypeCategory.NonNullableReferenceType => hasRequiredAttribute || _options.ValidateModelState,
-            TypeCategory.ValueType => hasRequiredAttribute,
-            TypeCategory.NullableReferenceType or TypeCategory.NullableValueType => hasRequiredAttribute,
-            _ => throw new UnreachableCodeException()
+            true => hasRequiredAttribute,
+            false => _options.ValidateModelState ? nullabilityInfo.ReadState == NullabilityState.NotNull || hasRequiredAttribute : hasRequiredAttribute
         };
     }
 
@@ -197,7 +204,9 @@ private OpenApiSchema CreateRelationshipSchema(Type relationshipSchemaType)
 
         OpenApiSchema fullSchema = _schemaRepositoryAccessor.Current.Schemas[referenceSchema.Reference.Id];
 
-        if (IsDataPropertyNullable(relationshipSchemaType))
+        Console.WriteLine(relationshipSchemaType.FullName);
+
+        if (IsDataPropertyNullableInRelationshipSchemaType(relationshipSchemaType))
         {
             fullSchema.Properties[JsonApiObjectPropertyName.Data] =
                 _nullableReferenceSchemaGenerator.GenerateSchema(fullSchema.Properties[JsonApiObjectPropertyName.Data]);
@@ -215,18 +224,12 @@ private static bool IsRelationshipInResponseType(Type relationshipSchemaType)
     {
         Type relationshipSchemaOpenType = relationshipSchemaType.GetGenericTypeDefinition();
 
-        return RelationshipInResponseOpenTypes.Contains(relationshipSchemaOpenType);
+        return RelationshipSchemaInResponseOpenTypes.Contains(relationshipSchemaOpenType);
     }
 
-    private static bool IsDataPropertyNullable(Type type)
+    private static bool IsDataPropertyNullableInRelationshipSchemaType(Type relationshipSchemaType)
     {
-        PropertyInfo? dataProperty = type.GetProperty(nameof(JsonApiObjectPropertyName.Data));
-
-        if (dataProperty == null)
-        {
-            throw new UnreachableCodeException();
-        }
-
-        return dataProperty.GetTypeCategory() == TypeCategory.NullableReferenceType;
+        Type relationshipSchemaOpenType = relationshipSchemaType.GetGenericTypeDefinition();
+        return NullableRelationshipSchemaOpenTypes.Contains(relationshipSchemaOpenType);
     }
 }

src/JsonApiDotNetCore.OpenApi/SwaggerComponents/ResourceFieldObjectSchemaBuilder.cs

@@ -6,24 +6,25 @@ namespace OpenApiClientTests;
 
 internal static class PropertyInfoAssertionsExtensions
 {
+    private static readonly NullabilityInfoContext NullabilityInfoContext = new();
+
     [CustomAssertion]
     public static void BeNullable(this PropertyInfoAssertions source, string because = "", params object[] becauseArgs)
     {
-        MemberInfo memberInfo = source.Subject;
+        PropertyInfo propertyInfo = source.Subject;
 
-        TypeCategory typeCategory = memberInfo.GetTypeCategory();
+        NullabilityInfo nullabilityInfo = NullabilityInfoContext.Create(propertyInfo);
 
-        typeCategory.Should().Match(category => category == TypeCategory.NullableReferenceType || category == TypeCategory.NullableValueType, because,
-            becauseArgs);
+        nullabilityInfo.ReadState.Should().NotBe(NullabilityState.NotNull, because, becauseArgs);
     }
 
     [CustomAssertion]
     public static void BeNonNullable(this PropertyInfoAssertions source, string because = "", params object[] becauseArgs)
     {
-        MemberInfo memberInfo = source.Subject;
+        PropertyInfo propertyInfo = source.Subject;
 
-        TypeCategory typeCategory = memberInfo.GetTypeCategory();
+        NullabilityInfo nullabilityInfo = NullabilityInfoContext.Create(propertyInfo);
 
-        typeCategory.Should().Match(category => category == TypeCategory.NonNullableReferenceType || category == TypeCategory.ValueType, because, becauseArgs);
+        nullabilityInfo.ReadState.Should().Be(NullabilityState.NotNull, because, becauseArgs);
     }
 }

src/JsonApiDotNetCore.OpenApi/TypeCategory.cs

@@ -7,7 +7,6 @@
 using OpenApiClientTests.SchemaProperties.NullableReferenceTypesDisabled.GeneratedCode;
 using TestBuildingBlocks;
 using Xunit;
-using NullableReferenceTypesDisabledClient = OpenApiClientTests.SchemaProperties.NullableReferenceTypesDisabled.GeneratedCode.NullableReferenceTypesDisabledClient;
 
 namespace OpenApiClientTests.SchemaProperties.NullableReferenceTypesDisabled;