Fix nullability check for nested record types. fixes domaindrivendev/…

…Swashbuckle.AspNetCore#2758 for Havunen/DotSwashbuckle#3

src/DotSwashbuckle.AspNetCore.SwaggerGen/SchemaGenerator/MemberInfoExtensions.cs

@@ -2,17 +2,13 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
+using System.Runtime.CompilerServices;
 using Microsoft.AspNetCore.Mvc;
 
 namespace DotSwashbuckle.AspNetCore.SwaggerGen
 {
     public static class MemberInfoExtensions
     {
-        private const string NullableAttributeFullTypeName = "System.Runtime.CompilerServices.NullableAttribute";
-        private const string NullableFlagsFieldName = "NullableFlags";
-        private const string NullableContextAttributeFullTypeName = "System.Runtime.CompilerServices.NullableContextAttribute";
-        private const string FlagFieldName = "Flag";
-
         public static ICollection<object> GetInlineAndMetadataAttributes(this MemberInfo memberInfo)
         {
             var attributes = memberInfo.GetCustomAttributes(true)
@@ -48,9 +44,7 @@ public static bool IsNonNullableReferenceType(this MemberInfo memberInfo)
                 return memberInfo.GetNullableFallbackValue();
             }
 
-            if (nullableAttribute.GetType().GetField(NullableFlagsFieldName) is FieldInfo field &&
-                field.GetValue(nullableAttribute) is byte[] flags &&
-                flags.Length >= 1 && flags[0] == 1)
+            if (nullableAttribute.NullableFlags.Length >= 1 && nullableAttribute.NullableFlags[0] == 1)
             {
                 return true;
             }
@@ -73,23 +67,17 @@ public static bool IsDictionaryValueNonNullable(this MemberInfo memberInfo)
                 return memberInfo.GetNullableFallbackValue();
             }
 
-            if (nullableAttribute.GetType().GetField(NullableFlagsFieldName) is FieldInfo field &&
-                field.GetValue(nullableAttribute) is byte[] flags &&
-                flags.Length == 3 && flags[2] == 1)
+            if (nullableAttribute.NullableFlags.Length == 3 && nullableAttribute.NullableFlags[2] == 1)
             {
                 return true;
             }
 
             return false;
         }
 
-        private static object GetNullableAttribute(this MemberInfo memberInfo)
+        private static NullableAttribute GetNullableAttribute(this MemberInfo memberInfo)
         {
-            var nullableAttribute = memberInfo.GetCustomAttributes()
-                .Where(attr => string.Equals(attr.GetType().FullName, NullableAttributeFullTypeName, StringComparison.Ordinal))
-                .FirstOrDefault();
-
-            return nullableAttribute;
+            return memberInfo.GetCustomAttribute<NullableAttribute>();
         }
 
         private static bool GetNullableFallbackValue(this MemberInfo memberInfo)
@@ -98,25 +86,30 @@ private static bool GetNullableFallbackValue(this MemberInfo memberInfo)
                 ? new Type[] { memberInfo.DeclaringType, memberInfo.DeclaringType.DeclaringType }
                 : new Type[] { memberInfo.DeclaringType };
 
+            // https://github.com/dotnet/roslyn/blob/main/docs/features/nullable-metadata.md
+            // Check NullableContextAttribute first
             foreach (var declaringType in declaringTypes)
             {
-                var attributes = (IEnumerable<object>)declaringType.GetCustomAttributes(false);
+                var attributes = declaringType.GetCustomAttributes(true);
 
-                var nullableContext = attributes
-                .Where(attr => string.Equals(attr.GetType().FullName, NullableContextAttributeFullTypeName, StringComparison.Ordinal))
-                .FirstOrDefault();
+                // NullableContextAttribute is optional
+                var nullableContextAttribute = (NullableContextAttribute)attributes.FirstOrDefault(a => a is NullableContextAttribute);
+
+                if (nullableContextAttribute != null)
+                {
+                    return nullableContextAttribute.Flag == 1;
+                }
+            }
+
+            // Next check NullableAttribute
+            foreach (var declaringType in declaringTypes)
+            {
+                var attributes = declaringType.GetCustomAttributes(true);
+                var nullableAttribute = (NullableAttribute)attributes.FirstOrDefault(a => a is NullableAttribute);
 
-                if (nullableContext != null)
+                if (nullableAttribute != null)
                 {
-                    if (nullableContext.GetType().GetField(FlagFieldName) is FieldInfo field &&
-                    field.GetValue(nullableContext) is byte flag && flag == 1)
-                    {
-                        return true;
-                    }
-                    else
-                    {
-                        return false;
-                    }
+                    return nullableAttribute.NullableFlags.Length >= 1 && nullableAttribute.NullableFlags[0] == 1;
                 }
             }
 

test/DotSwashbuckle.AspNetCore.Newtonsoft.Test/SchemaGenerator/NewtonsoftSchemaGeneratorTests.cs

@@ -353,6 +353,36 @@ public void GenerateSchema_SetsValidationProperties_IfComplexTypeHasValidationAt
             Assert.Equal(new[] { "StringWithRequired", "StringWithRequiredAllowEmptyTrue", "StringWithRequiredModifier" }, schema.Required.ToArray());
         }
 
+        [Fact]
+        public void GenerateSchema_NestedRecords_RecordTypeWithNonNestedChild_NullableCheck()
+        {
+            var schemaRepository = new SchemaRepository();
+
+            Subject(
+                (options) => options.SupportNonNullableReferenceTypes = true
+            ).GenerateSchema(typeof(RecordTypeWithNonNestedChild), schemaRepository);
+
+            var schema = schemaRepository.Schemas[nameof(RecordChild)];
+
+            Assert.False(schema.Properties[nameof(RecordChild.NonNullable)].Nullable);
+            Assert.True(schema.Properties[nameof(RecordChild.Nullable)].Nullable);
+        }
+
+        [Fact]
+        public void GenerateSchema_NestedRecords_RecordTypeWithNestedChild_NullableCheck()
+        {
+            var schemaRepository = new SchemaRepository();
+
+            Subject(
+                (options) => options.SupportNonNullableReferenceTypes = true
+            ).GenerateSchema(typeof(RecordTypeWithNestedChild), schemaRepository);
+
+            var schema = schemaRepository.Schemas[nameof(RecordTypeWithNestedChild.NestedChild)];
+
+            Assert.False(schema.Properties[nameof(RecordTypeWithNestedChild.NestedChild.NonNullable)].Nullable);
+            Assert.True(schema.Properties[nameof(RecordTypeWithNestedChild.NestedChild.Nullable)].Nullable);
+        }
+
         [Fact]
         public void GenerateSchema_SetsReadOnlyAndWriteOnlyFlags_IfPropertyIsRestricted()
         {

test/DotSwashbuckle.AspNetCore.TestSupport/DotSwashbuckle.AspNetCore.TestSupport.csproj

@@ -8,6 +8,7 @@
     <IsUnitTestProject>false</IsUnitTestProject>
     <IsTestProject>false</IsTestProject>
     <DefineTrace>true</DefineTrace>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>

test/DotSwashbuckle.AspNetCore.TestSupport/Fixtures/NestedRecords.cs

@@ -0,0 +1,10 @@
+namespace DotSwashbuckle.AspNetCore.TestSupport.Fixtures
+{
+    public record RecordTypeWithNestedChild(RecordTypeWithNestedChild.NestedChild Child)
+    {
+        public record NestedChild(string NonNullable, string? Nullable);
+    }
+
+    public record RecordTypeWithNonNestedChild(RecordChild RecordChild);
+    public record RecordChild(string NonNullable, string? Nullable);
+}

test/WebSites/Basic/Basic.csproj

@@ -4,6 +4,7 @@
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <NoWarn>$(NoWarn);1591</NoWarn>
     <TargetFrameworks>net8.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>

test/WebSites/Basic/Startup.cs

@@ -28,6 +28,7 @@ public void ConfigureServices(IServiceCollection services)
 
             services.AddSwaggerGen(c =>
             {
+                c.SupportNonNullableReferenceTypes();
                 c.SwaggerDoc("v1",
                     new OpenApiInfo
                     {
@@ -78,8 +79,11 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
                 {
                     c.SerializeAsV2 = true;
                 });
+                endpoints.MapPost("/requestWithNestedChild", (Requests.RequestWithNestedChild request) => "ok");
+                endpoints.MapPost("/requestWithNonNestedChild", (Requests.RequestWithNonNestedChild request) => "ok");
             });
 
+
             var supportedCultures = new[]
             {
                 new CultureInfo("en-US"),
@@ -102,5 +106,16 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
                 c.SwaggerEndpoint("/swagger/v1/swagger.json", "V1 Docs");
             });
         }
+
+        public class Requests
+        {
+            public record RequestWithNestedChild(RequestWithNestedChild.NestedChild Child)
+            {
+                public record NestedChild(string NonNullable, string? Nullable);
+            }
+
+            public record RequestWithNonNestedChild(Child Child);
+            public record Child(string NonNullable, string? Nullable);
+        }
     }
 }