Nullability annotation for scaffolding

src/EFCore.Design/Scaffolding/IModelCodeGenerator.cs

@@ -5,6 +5,8 @@
 using Microsoft.EntityFrameworkCore.Design;
 using Microsoft.EntityFrameworkCore.Metadata;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding
 {
     /// <summary>

src/EFCore.Design/Scaffolding/IModelCodeGeneratorSelector.cs

@@ -3,6 +3,8 @@
 
 using JetBrains.Annotations;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding
 {
     /// <summary>
@@ -15,6 +17,6 @@ public interface IModelCodeGeneratorSelector
         /// </summary>
         /// <param name="language"> The programming language. </param>
         /// <returns> The <see cref="IModelCodeGenerator" />. </returns>
-        IModelCodeGenerator Select([CanBeNull] string language);
+        IModelCodeGenerator Select([CanBeNull] string? language);
     }
 }

src/EFCore.Design/Scaffolding/IReverseEngineerScaffolder.cs

@@ -3,6 +3,8 @@
 
 using JetBrains.Annotations;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding
 {
     /// <summary>
@@ -33,7 +35,7 @@ ScaffoldedModel ScaffoldModel(
         /// <returns> The model files. </returns>
         SavedModelFiles Save(
             [NotNull] ScaffoldedModel scaffoldedModel,
-            [CanBeNull] string outputDir,
+            [NotNull] string outputDir,
             bool overwriteFiles);
     }
 }

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

@@ -15,6 +15,8 @@
 using Microsoft.EntityFrameworkCore.Metadata.Internal;
 using Microsoft.EntityFrameworkCore.Utilities;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding.Internal
 {
     /// <summary>
@@ -31,7 +33,7 @@ public class CSharpDbContextGenerator : ICSharpDbContextGenerator
         private readonly ICSharpHelper _code;
         private readonly IProviderConfigurationCodeGenerator _providerConfigurationCodeGenerator;
         private readonly IAnnotationCodeGenerator _annotationCodeGenerator;
-        private IndentedStringBuilder _sb;
+        private IndentedStringBuilder _sb = null!;
         private bool _entityTypeBuilderInitialized;
 
         /// <summary>
@@ -64,7 +66,7 @@ public virtual string WriteCode(
             IModel model,
             string contextName,
             string connectionString,
-            string contextNamespace,
+            string? contextNamespace,
             string modelNamespace,
             bool useDataAnnotations,
             bool suppressConnectionStringWarning)

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

@@ -14,6 +14,8 @@
 using Microsoft.EntityFrameworkCore.Metadata.Internal;
 using Microsoft.EntityFrameworkCore.Utilities;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding.Internal
 {
     /// <summary>
@@ -26,7 +28,7 @@ public class CSharpEntityTypeGenerator : ICSharpEntityTypeGenerator
     {
         private readonly ICSharpHelper _code;
 
-        private IndentedStringBuilder _sb;
+        private IndentedStringBuilder _sb = null!;
         private bool _useDataAnnotations;
 
         /// <summary>

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

@@ -1,11 +1,14 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using System.IO;
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.Metadata;
 using Microsoft.EntityFrameworkCore.Utilities;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding.Internal
 {
     /// <summary>
@@ -74,7 +77,20 @@ public override ScaffoldedModel GenerateModel(
             Check.NotNull(model, nameof(model));
             Check.NotNull(options, nameof(options));
 
-            var resultingFiles = new ScaffoldedModel();
+            if (options.ContextName == null)
+            {
+                throw new ArgumentException($"{nameof(options.ContextName)} cannot be null", nameof(options));
+            }
+
+            if (options.ConnectionString == null)
+            {
+                throw new ArgumentException($"{nameof(options.ConnectionString)} cannot be null", nameof(options));
+            }
+
+            if (options.ModelNamespace == null)
+            {
+                throw new ArgumentException($"{nameof(options.ModelNamespace)} cannot be null", nameof(options));
+            }
 
             var generatedCode = CSharpDbContextGenerator.WriteCode(
                 model,
@@ -87,13 +103,12 @@ public override ScaffoldedModel GenerateModel(
 
             // output DbContext .cs file
             var dbContextFileName = options.ContextName + FileExtension;
-            resultingFiles.ContextFile = new ScaffoldedFile
-            {
-                Path = options.ContextDir != null
-                    ? Path.Combine(options.ContextDir, dbContextFileName)
-                    : dbContextFileName,
-                Code = generatedCode
-            };
+            var resultingFiles = new ScaffoldedModel(
+                new ScaffoldedFile(
+                    options.ContextDir != null
+                        ? Path.Combine(options.ContextDir, dbContextFileName)
+                        : dbContextFileName,
+                    generatedCode));
 
             foreach (var entityType in model.GetEntityTypes())
             {
@@ -102,7 +117,7 @@ public override ScaffoldedModel GenerateModel(
                 // output EntityType poco .cs file
                 var entityTypeFileName = entityType.DisplayName() + FileExtension;
                 resultingFiles.AdditionalFiles.Add(
-                    new ScaffoldedFile { Path = entityTypeFileName, Code = generatedCode });
+                    new ScaffoldedFile(entityTypeFileName, generatedCode));
             }
 
             return resultingFiles;

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

@@ -6,6 +6,8 @@
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.Utilities;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding.Internal
 {
     /// <summary>
@@ -18,7 +20,7 @@ public class CSharpNamer<T>
     {
         private readonly Func<T, string> _nameGetter;
         private readonly ICSharpUtilities _cSharpUtilities;
-        private readonly Func<string, string> _singularizePluralizer;
+        private readonly Func<string, string>? _singularizePluralizer;
 
         /// <summary>
         ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
@@ -37,7 +39,7 @@ public class CSharpNamer<T>
         public CSharpNamer(
             [NotNull] Func<T, string> nameGetter,
             [NotNull] ICSharpUtilities cSharpUtilities,
-            [CanBeNull] Func<string, string> singularizePluralizer)
+            [CanBeNull] Func<string, string>? singularizePluralizer)
         {
             Check.NotNull(nameGetter, nameof(nameGetter));
             Check.NotNull(cSharpUtilities, nameof(cSharpUtilities));

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

@@ -5,6 +5,8 @@
 using System.Collections.Generic;
 using JetBrains.Annotations;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding.Internal
 {
     /// <summary>
@@ -26,7 +28,7 @@ public class CSharpUniqueNamer<T> : CSharpNamer<T>
         public CSharpUniqueNamer(
             [NotNull] Func<T, string> nameGetter,
             [NotNull] ICSharpUtilities cSharpUtilities,
-            [CanBeNull] Func<string, string> singularizePluralizer)
+            [CanBeNull] Func<string, string>? singularizePluralizer)
             : this(nameGetter, null, cSharpUtilities, singularizePluralizer)
         {
         }
@@ -39,9 +41,9 @@ public CSharpUniqueNamer(
         /// </summary>
         public CSharpUniqueNamer(
             [NotNull] Func<T, string> nameGetter,
-            [CanBeNull] IEnumerable<string> usedNames,
+            [CanBeNull] IEnumerable<string>? usedNames,
             [NotNull] ICSharpUtilities cSharpUtilities,
-            [CanBeNull] Func<string, string> singularizePluralizer)
+            [CanBeNull] Func<string, string>? singularizePluralizer)
             : base(nameGetter, cSharpUtilities, singularizePluralizer)
         {
             if (usedNames != null)

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

@@ -8,6 +8,8 @@
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.Utilities;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding.Internal
 {
     /// <summary>
@@ -122,8 +124,8 @@ public virtual bool IsCSharpKeyword(string identifier)
         /// </summary>
         public virtual string GenerateCSharpIdentifier(
             string identifier,
-            ICollection<string> existingIdentifiers,
-            Func<string, string> singularizePluralizer)
+            ICollection<string>? existingIdentifiers,
+            Func<string, string>? singularizePluralizer)
             => GenerateCSharpIdentifier(identifier, existingIdentifiers, singularizePluralizer, Uniquifier);
 
         /// <summary>
@@ -134,9 +136,9 @@ public virtual string GenerateCSharpIdentifier(
         /// </summary>
         public virtual string GenerateCSharpIdentifier(
             string identifier,
-            ICollection<string> existingIdentifiers,
-            Func<string, string> singularizePluralizer,
-            Func<string, ICollection<string>, string> uniquifier)
+            ICollection<string>? existingIdentifiers,
+            Func<string, string>? singularizePluralizer,
+            Func<string, ICollection<string>?, string> uniquifier)
         {
             Check.NotNull(identifier, nameof(identifier));
             Check.NotNull(uniquifier, nameof(uniquifier));
@@ -177,7 +179,7 @@ public virtual string GenerateCSharpIdentifier(
         ///     doing so can result in application failures when updating to a new Entity Framework Core release.
         /// </summary>
         public virtual string Uniquifier(
-            [NotNull] string proposedIdentifier, [CanBeNull] ICollection<string> existingIdentifiers)
+            [NotNull] string proposedIdentifier, [CanBeNull] ICollection<string>? existingIdentifiers)
         {
             Check.NotEmpty(proposedIdentifier, nameof(proposedIdentifier));
 
@@ -203,7 +205,7 @@ public virtual string Uniquifier(
         ///     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 bool IsValidIdentifier(string name)
+        public virtual bool IsValidIdentifier(string? name)
         {
             if (string.IsNullOrEmpty(name))
             {

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

@@ -9,6 +9,8 @@
 using Microsoft.EntityFrameworkCore.Scaffolding.Metadata;
 using Microsoft.EntityFrameworkCore.Utilities;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding.Internal
 {
     /// <summary>
@@ -26,9 +28,7 @@ public class CandidateNamingService : ICandidateNamingService
         ///     doing so can result in application failures when updating to a new Entity Framework Core release.
         /// </summary>
         public virtual string GenerateCandidateIdentifier(DatabaseTable originalTable)
-        {
-            return GenerateCandidateIdentifier(originalTable.Name);
-        }
+            => GenerateCandidateIdentifier(originalTable.Name);
 
         /// <summary>
         ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
@@ -37,9 +37,7 @@ public virtual string GenerateCandidateIdentifier(DatabaseTable originalTable)
         ///     doing so can result in application failures when updating to a new Entity Framework Core release.
         /// </summary>
         public virtual string GenerateCandidateIdentifier(DatabaseColumn originalColumn)
-        {
-            return GenerateCandidateIdentifier(originalColumn.Name);
-        }
+            => GenerateCandidateIdentifier(originalColumn.Name);
 
         /// <summary>
         ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to

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

@@ -4,6 +4,8 @@
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.Metadata;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding.Internal
 {
     /// <summary>
@@ -24,7 +26,7 @@ string WriteCode(
             [NotNull] IModel model,
             [NotNull] string contextName,
             [NotNull] string connectionString,
-            [NotNull] string contextNamespace,
+            [CanBeNull] string? contextNamespace,
             [NotNull] string modelNamespace,
             bool useDataAnnotations,
             bool suppressConnectionStringWarning);

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

@@ -4,6 +4,8 @@
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.Metadata;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding.Internal
 {
     /// <summary>

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

@@ -5,6 +5,8 @@
 using System.Collections.Generic;
 using JetBrains.Annotations;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding.Internal
 {
     /// <summary>
@@ -22,8 +24,8 @@ public interface ICSharpUtilities
         ///     doing so can result in application failures when updating to a new Entity Framework Core release.
         /// </summary>
         string GenerateCSharpIdentifier(
-            [NotNull] string identifier, [CanBeNull] ICollection<string> existingIdentifiers,
-            [CanBeNull] Func<string, string> singularizePluralizer);
+            [NotNull] string identifier, [CanBeNull] ICollection<string>? existingIdentifiers,
+            [CanBeNull] Func<string, string>? singularizePluralizer);
 
         /// <summary>
         ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
@@ -32,8 +34,8 @@ string GenerateCSharpIdentifier(
         ///     doing so can result in application failures when updating to a new Entity Framework Core release.
         /// </summary>
         string GenerateCSharpIdentifier(
-            [NotNull] string identifier, [CanBeNull] ICollection<string> existingIdentifiers,
-            [CanBeNull] Func<string, string> singularizePluralizer, [NotNull] Func<string, ICollection<string>, string> uniquifier);
+            [NotNull] string identifier, [CanBeNull] ICollection<string>? existingIdentifiers,
+            [CanBeNull] Func<string, string>? singularizePluralizer, [NotNull] Func<string, ICollection<string>?, string> uniquifier);
 
         /// <summary>
         ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
@@ -49,6 +51,6 @@ string GenerateCSharpIdentifier(
         ///     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>
-        bool IsValidIdentifier([CanBeNull] string name);
+        bool IsValidIdentifier([CanBeNull] string? name);
     }
 }

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

@@ -5,6 +5,8 @@
 using Microsoft.EntityFrameworkCore.Metadata;
 using Microsoft.EntityFrameworkCore.Scaffolding.Metadata;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding.Internal
 {
     /// <summary>

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

@@ -5,6 +5,8 @@
 using Microsoft.EntityFrameworkCore.Metadata;
 using Microsoft.EntityFrameworkCore.Scaffolding.Metadata;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding.Internal
 {
     /// <summary>

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

@@ -3,6 +3,8 @@
 
 using JetBrains.Annotations;
 
+#nullable enable
+
 namespace Microsoft.EntityFrameworkCore.Scaffolding.Internal
 {
     /// <summary>
@@ -19,6 +21,6 @@ public interface IScaffoldingTypeMapper
         ///     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>
-        TypeScaffoldingInfo FindMapping([NotNull] string storeType, bool keyOrIndex, bool rowVersion);
+        TypeScaffoldingInfo? FindMapping([NotNull] string storeType, bool keyOrIndex, bool rowVersion);
     }
 }