Scaffold with nullable reference types

src/EFCore.Design/Design/Internal/DatabaseOperations.cs

@@ -111,7 +111,7 @@ public virtual SavedModelFiles ScaffoldContext(
                     ModelNamespace = finalModelNamespace,
                     ContextNamespace = finalContextNamespace,
                     Language = _language,
-                    Nullable = _nullable,
+                    UseNullableReferenceTypes = _nullable,
                     ContextDir = MakeDirRelative(outputDir, outputContextDir),
                     ContextName = dbContextClassName,
                     SuppressOnConfiguring = suppressOnConfiguring

src/EFCore.Design/Scaffolding/Internal/CSharpDbContextGenerator.cs

@@ -30,6 +30,8 @@ public class CSharpDbContextGenerator : ICSharpDbContextGenerator
         private readonly IAnnotationCodeGenerator _annotationCodeGenerator;
         private IndentedStringBuilder _sb = null!;
         private bool _entityTypeBuilderInitialized;
+        private bool _useDataAnnotations;
+        private bool _useNullableReferenceTypes;
 
         /// <summary>
         ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
@@ -64,11 +66,15 @@ public virtual string WriteCode(
             string? contextNamespace,
             string? modelNamespace,
             bool useDataAnnotations,
+            bool useNullableReferenceTypes,
             bool suppressConnectionStringWarning,
             bool suppressOnConfiguring)
         {
             Check.NotNull(model, nameof(model));
 
+            _useDataAnnotations = useDataAnnotations;
+            _useNullableReferenceTypes = useNullableReferenceTypes;
+
             _sb = new IndentedStringBuilder();
 
             _sb.AppendLine("using System;"); // Guid default values require new Guid() which requires this using
@@ -84,9 +90,6 @@ public virtual string WriteCode(
 
             _sb.AppendLine();
 
-            _sb.AppendLine("#nullable disable");
-            _sb.AppendLine();
-
             if (!string.IsNullOrEmpty(finalContextNamespace))
             {
                 _sb.AppendLine($"namespace {finalContextNamespace}");
@@ -98,7 +101,6 @@ public virtual string WriteCode(
                 model,
                 contextName,
                 connectionString,
-                useDataAnnotations,
                 suppressConnectionStringWarning,
                 suppressOnConfiguring);
 
@@ -121,7 +123,6 @@ protected virtual void GenerateClass(
             IModel model,
             string contextName,
             string connectionString,
-            bool useDataAnnotations,
             bool suppressConnectionStringWarning,
             bool suppressOnConfiguring)
         {
@@ -142,7 +143,7 @@ protected virtual void GenerateClass(
                     GenerateOnConfiguring(connectionString, suppressConnectionStringWarning);
                 }
 
-                GenerateOnModelCreating(model, useDataAnnotations);
+                GenerateOnModelCreating(model);
             }
 
             _sb.AppendLine();
@@ -175,8 +176,14 @@ private void GenerateDbSets(IModel model)
         {
             foreach (var entityType in model.GetEntityTypes())
             {
-                _sb.AppendLine(
-                    $"public virtual DbSet<{entityType.Name}> {entityType.GetDbSetName()} {{ get; set; }}");
+                _sb.Append($"public virtual DbSet<{entityType.Name}> {entityType.GetDbSetName()} {{ get; set; }}");
+
+                if (_useNullableReferenceTypes)
+                {
+                    _sb.Append(" = null!;");
+                }
+
+                _sb.AppendLine();
             }
 
             if (model.GetEntityTypes().Any())
@@ -258,9 +265,7 @@ protected virtual void GenerateOnConfiguring(
         ///     any release. You should only use it directly in your code with extreme caution and knowing that
         ///     doing so can result in application failures when updating to a new Entity Framework Core release.
         /// </summary>
-        protected virtual void GenerateOnModelCreating(
-            IModel model,
-            bool useDataAnnotations)
+        protected virtual void GenerateOnModelCreating(IModel model)
         {
             Check.NotNull(model, nameof(model));
 
@@ -310,7 +315,7 @@ protected virtual void GenerateOnModelCreating(
                 {
                     _entityTypeBuilderInitialized = false;
 
-                    GenerateEntityType(entityType, useDataAnnotations);
+                    GenerateEntityType(entityType);
 
                     if (_entityTypeBuilderInitialized)
                     {
@@ -346,9 +351,9 @@ private void InitializeEntityTypeBuilder(IEntityType entityType)
             _entityTypeBuilderInitialized = true;
         }
 
-        private void GenerateEntityType(IEntityType entityType, bool useDataAnnotations)
+        private void GenerateEntityType(IEntityType entityType)
         {
-            GenerateKey(entityType.FindPrimaryKey(), entityType, useDataAnnotations);
+            GenerateKey(entityType.FindPrimaryKey(), entityType);
 
             var annotations = _annotationCodeGenerator
                 .FilterIgnoredAnnotations(entityType.GetAnnotations())
@@ -362,14 +367,14 @@ private void GenerateEntityType(IEntityType entityType, bool useDataAnnotations)
             annotations.Remove(ScaffoldingAnnotationNames.DbSetName);
             annotations.Remove(RelationalAnnotationNames.ViewDefinitionSql);
 
-            if (useDataAnnotations)
+            if (_useDataAnnotations)
             {
                 // Strip out any annotations handled as attributes - these are already handled when generating
                 // the entity's properties
                 _ = _annotationCodeGenerator.GenerateDataAnnotationAttributes(entityType, annotations);
             }
 
-            if (!useDataAnnotations || entityType.GetViewName() != null)
+            if (!_useDataAnnotations || entityType.GetViewName() != null)
             {
                 GenerateTableName(entityType);
             }
@@ -389,20 +394,20 @@ private void GenerateEntityType(IEntityType entityType, bool useDataAnnotations)
                     .ToDictionary(a => a.Name, a => a);
                 _annotationCodeGenerator.RemoveAnnotationsHandledByConventions(index, indexAnnotations);
 
-                if (!useDataAnnotations || indexAnnotations.Count > 0)
+                if (!_useDataAnnotations || indexAnnotations.Count > 0)
                 {
                     GenerateIndex(index);
                 }
             }
 
             foreach (var property in entityType.GetProperties())
             {
-                GenerateProperty(property, useDataAnnotations);
+                GenerateProperty(property);
             }
 
             foreach (var foreignKey in entityType.GetForeignKeys())
             {
-                GenerateRelationship(foreignKey, useDataAnnotations);
+                GenerateRelationship(foreignKey);
             }
         }
 
@@ -434,11 +439,11 @@ private void AppendMultiLineFluentApi(IEntityType entityType, IList<string> line
             }
         }
 
-        private void GenerateKey(IKey? key, IEntityType entityType, bool useDataAnnotations)
+        private void GenerateKey(IKey? key, IEntityType entityType)
         {
             if (key == null)
             {
-                if (!useDataAnnotations)
+                if (!_useDataAnnotations)
                 {
                     var line = new List<string> { $".{nameof(EntityTypeBuilder.HasNoKey)}()" };
 
@@ -469,7 +474,7 @@ private void GenerateKey(IKey? key, IEntityType entityType, bool useDataAnnotati
                 }
 
                 if (!explicitName
-                    && useDataAnnotations)
+                    && _useDataAnnotations)
                 {
                     return;
                 }
@@ -557,7 +562,7 @@ private void GenerateIndex(IIndex index)
             AppendMultiLineFluentApi(index.DeclaringEntityType, lines);
         }
 
-        private void GenerateProperty(IProperty property, bool useDataAnnotations)
+        private void GenerateProperty(IProperty property)
         {
             var lines = new List<string> { $".{nameof(EntityTypeBuilder.Property)}({_code.Lambda(new[] { property.Name }, "e")})" };
 
@@ -567,7 +572,7 @@ private void GenerateProperty(IProperty property, bool useDataAnnotations)
             _annotationCodeGenerator.RemoveAnnotationsHandledByConventions(property, annotations);
             annotations.Remove(ScaffoldingAnnotationNames.ColumnOrdinal);
 
-            if (useDataAnnotations)
+            if (_useDataAnnotations)
             {
                 // Strip out any annotations handled as attributes - these are already handled when generating
                 // the entity's properties
@@ -579,7 +584,8 @@ private void GenerateProperty(IProperty property, bool useDataAnnotations)
             }
             else
             {
-                if (!property.IsNullable
+                if ((!_useNullableReferenceTypes || property.ClrType.IsValueType)
+                    && !property.IsNullable
                     && property.ClrType.IsNullableType()
                     && !property.IsPrimaryKey())
                 {
@@ -679,7 +685,7 @@ private void GenerateProperty(IProperty property, bool useDataAnnotations)
             AppendMultiLineFluentApi(property.DeclaringEntityType, lines);
         }
 
-        private void GenerateRelationship(IForeignKey foreignKey, bool useDataAnnotations)
+        private void GenerateRelationship(IForeignKey foreignKey)
         {
             var canUseDataAnnotations = true;
             var annotations = _annotationCodeGenerator
@@ -732,7 +738,7 @@ private void GenerateRelationship(IForeignKey foreignKey, bool useDataAnnotation
                 _annotationCodeGenerator.GenerateFluentApiCalls(foreignKey, annotations).Select(m => _code.Fragment(m))
                     .Concat(GenerateAnnotations(annotations.Values)));
 
-            if (!useDataAnnotations
+            if (!_useDataAnnotations
                 || !canUseDataAnnotations)
             {
                 AppendMultiLineFluentApi(foreignKey.DeclaringEntityType, lines);

src/EFCore.Design/Scaffolding/Internal/CSharpEntityTypeGenerator.cs

@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
+using System.Globalization;
 using System.Linq;
 using Microsoft.EntityFrameworkCore.Design;
 using Microsoft.EntityFrameworkCore.Design.Internal;
@@ -28,6 +29,7 @@ public class CSharpEntityTypeGenerator : ICSharpEntityTypeGenerator
 
         private IndentedStringBuilder _sb = null!;
         private bool _useDataAnnotations;
+        private bool _useNullableReferenceTypes;
 
         /// <summary>
         ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
@@ -51,12 +53,14 @@ public CSharpEntityTypeGenerator(
         ///     any release. You should only use it directly in your code with extreme caution and knowing that
         ///     doing so can result in application failures when updating to a new Entity Framework Core release.
         /// </summary>
-        public virtual string WriteCode(IEntityType entityType, string? @namespace, bool useDataAnnotations)
+        public virtual string WriteCode(IEntityType entityType, string? @namespace, bool useDataAnnotations, bool useNullableReferenceTypes)
         {
             Check.NotNull(entityType, nameof(entityType));
 
-            _sb = new IndentedStringBuilder();
             _useDataAnnotations = useDataAnnotations;
+            _useNullableReferenceTypes = useNullableReferenceTypes;
+
+            _sb = new IndentedStringBuilder();
 
             _sb.AppendLine("using System;");
             _sb.AppendLine("using System.Collections.Generic;");
@@ -77,9 +81,6 @@ public virtual string WriteCode(IEntityType entityType, string? @namespace, bool
                 _sb.AppendLine($"using {ns};");
             }
 
-            _sb.AppendLine();
-            _sb.AppendLine("#nullable disable");
-
             _sb.AppendLine();
 
             if (!string.IsNullOrEmpty(@namespace))
@@ -277,7 +278,12 @@ protected virtual void GenerateProperties(IEntityType entityType)
                     GeneratePropertyDataAnnotations(property);
                 }
 
-                _sb.AppendLine($"public {_code.Reference(property.ClrType)} {property.Name} {{ get; set; }}");
+                _sb.AppendLine(
+                    !_useNullableReferenceTypes || property.ClrType.IsValueType
+                        ? $"public {_code.Reference(property.ClrType)} {property.Name} {{ get; set; }}"
+                        : property.IsNullable
+                            ? $"public {_code.Reference(property.ClrType)}? {property.Name} {{ get; set; }}"
+                            : $"public {_code.Reference(property.ClrType)} {property.Name} {{ get; set; }} = null!;");
             }
         }
 
@@ -350,7 +356,8 @@ private void GenerateColumnAttribute(IProperty property)
 
         private void GenerateRequiredAttribute(IProperty property)
         {
-            if (!property.IsNullable
+            if ((!_useNullableReferenceTypes || property.ClrType.IsValueType)
+                && !property.IsNullable
                 && property.ClrType.IsNullableType()
                 && !property.IsPrimaryKey())
             {
@@ -440,7 +447,13 @@ protected virtual void GenerateNavigationProperties(IEntityType entityType)
 
                     var referencedTypeName = navigation.TargetEntityType.Name;
                     var navigationType = navigation.IsCollection ? $"ICollection<{referencedTypeName}>" : referencedTypeName;
-                    _sb.AppendLine($"public virtual {navigationType} {navigation.Name} {{ get; set; }}");
+
+                    _sb.AppendLine(
+                        !_useNullableReferenceTypes || navigation.IsCollection
+                            ? $"public virtual {navigationType} {navigation.Name} {{ get; set; }}"
+                            : navigation.ForeignKey.IsRequired
+                                ? $"public virtual {navigationType} {navigation.Name} {{ get; set; }} = null!;"
+                                : $"public virtual {navigationType}? {navigation.Name} {{ get; set; }}");
                 }
             }
         }

src/EFCore.Design/Scaffolding/Internal/CSharpModelGenerator.cs

@@ -88,14 +88,14 @@ public override ScaffoldedModel GenerateModel(
                     CoreStrings.ArgumentPropertyNull(nameof(options.ConnectionString), nameof(options)), nameof(options));
             }
 
-            // TODO: Honor options.Nullable (issue #15520)
             var generatedCode = CSharpDbContextGenerator.WriteCode(
                 model,
                 options.ContextName,
                 options.ConnectionString,
                 options.ContextNamespace,
                 options.ModelNamespace,
                 options.UseDataAnnotations,
+                options.UseNullableReferenceTypes,
                 options.SuppressConnectionStringWarning,
                 options.SuppressOnConfiguring);
 
@@ -114,8 +114,11 @@ public override ScaffoldedModel GenerateModel(
 
             foreach (var entityType in model.GetEntityTypes())
             {
-                // TODO: Honor options.Nullable (issue #15520)
-                generatedCode = CSharpEntityTypeGenerator.WriteCode(entityType, options.ModelNamespace, options.UseDataAnnotations);
+                generatedCode = CSharpEntityTypeGenerator.WriteCode(
+                    entityType,
+                    options.ModelNamespace,
+                    options.UseDataAnnotations,
+                    options.UseNullableReferenceTypes);
 
                 // output EntityType poco .cs file
                 var entityTypeFileName = entityType.Name + FileExtension;

src/EFCore.Design/Scaffolding/Internal/ICSharpDbContextGenerator.cs

@@ -26,6 +26,7 @@ string WriteCode(
             string? contextNamespace,
             string? modelNamespace,
             bool useDataAnnotations,
+            bool useNullableReferenceTypes,
             bool suppressConnectionStringWarning,
             bool suppressOnConfiguring);
     }

src/EFCore.Design/Scaffolding/Internal/ICSharpEntityTypeGenerator.cs

@@ -19,6 +19,6 @@ public interface ICSharpEntityTypeGenerator
         ///     any release. You should only use it directly in your code with extreme caution and knowing that
         ///     doing so can result in application failures when updating to a new Entity Framework Core release.
         /// </summary>
-        string WriteCode(IEntityType entityType, string? @namespace, bool useDataAnnotations);
+        string WriteCode(IEntityType entityType, string? @namespace, bool useDataAnnotations, bool useNullableReferenceTypes);
     }
 }

src/EFCore.Design/Scaffolding/ModelCodeGenerationOptions.cs

@@ -54,7 +54,7 @@ public class ModelCodeGenerationOptions
         ///     Gets or sets a value indicating whether nullable reference types are enabled.
         /// </summary>
         /// <value> A value indicating whether nullable reference types are enabled. </value>
-        public virtual bool Nullable { get; set; }
+        public virtual bool UseNullableReferenceTypes { get; set; }
 
         /// <summary>
         ///     Gets or sets the DbContext output directory.