API Review: revert scaffolding nullability breaking changes

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

@@ -104,12 +104,16 @@ public override ScaffoldedModel GenerateModel(
 
             // output DbContext .cs file
             var dbContextFileName = options.ContextName + FileExtension;
-            var resultingFiles = new ScaffoldedModel(
-                new ScaffoldedFile(
-                    options.ContextDir != null
+            var resultingFiles = new ScaffoldedModel
+            {
+                ContextFile = new ScaffoldedFile
+                {
+                    Path = options.ContextDir != null
                         ? Path.Combine(options.ContextDir, dbContextFileName)
                         : dbContextFileName,
-                    generatedCode));
+                    Code = generatedCode
+                }
+            };
 
             foreach (var entityType in model.GetEntityTypes())
             {
@@ -118,7 +122,7 @@ public override ScaffoldedModel GenerateModel(
                 // output EntityType poco .cs file
                 var entityTypeFileName = entityType.DisplayName() + FileExtension;
                 resultingFiles.AdditionalFiles.Add(
-                    new ScaffoldedFile(entityTypeFileName, generatedCode));
+                    new ScaffoldedFile { Path = entityTypeFileName, Code = generatedCode });
             }
 
             return resultingFiles;

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

@@ -28,7 +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)
-            => GenerateCandidateIdentifier(originalTable.Name);
+            => GenerateCandidateIdentifier(originalTable.Name!);
 
         /// <summary>
         ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
@@ -37,7 +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)
-            => 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/RelationalScaffoldingModelFactory.cs

@@ -36,6 +36,7 @@ public class RelationalScaffoldingModelFactory : IScaffoldingModelFactory
         private readonly ICandidateNamingService _candidateNamingService;
         private Dictionary<DatabaseTable, CSharpUniqueNamer<DatabaseColumn>> _columnNamers;
         private bool _useDatabaseNames;
+        private readonly DatabaseTable _nullTable = new DatabaseTable();
         private CSharpUniqueNamer<DatabaseTable> _tableNamer;
         private CSharpUniqueNamer<DatabaseTable> _dbSetNamer;
         private readonly HashSet<DatabaseColumn> _unmappedColumns = new HashSet<DatabaseColumn>();
@@ -137,8 +138,12 @@ protected virtual string GetPropertyName([NotNull] DatabaseColumn column)
         {
             Check.NotNull(column, nameof(column));
 
-            var table = column.Table;
-            var usedNames = new List<string> { GetEntityTypeName(table) };
+            var table = column.Table ?? _nullTable;
+            var usedNames = new List<string>();
+            if (column.Table != null)
+            {
+                usedNames.Add(GetEntityTypeName(table));
+            }
 
             if (!_columnNamers.ContainsKey(table))
             {

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

@@ -153,7 +153,7 @@ public virtual SavedModelFiles Save(
 
             Directory.CreateDirectory(outputDir);
 
-            var contextPath = Path.GetFullPath(Path.Combine(outputDir, scaffoldedModel.ContextFile.Path));
+            var contextPath = Path.GetFullPath(Path.Combine(outputDir, scaffoldedModel.ContextFile!.Path));
             Directory.CreateDirectory(Path.GetDirectoryName(contextPath));
             File.WriteAllText(contextPath, scaffoldedModel.ContextFile.Code, Encoding.UTF8);
 
@@ -174,7 +174,7 @@ private static void CheckOutputFiles(
             bool overwriteFiles)
         {
             var paths = scaffoldedModel.AdditionalFiles.Select(f => f.Path).ToList();
-            paths.Insert(0, scaffoldedModel.ContextFile.Path);
+            paths.Insert(0, scaffoldedModel.ContextFile!.Path);
 
             var existingFiles = new List<string>();
             var readOnlyFiles = new List<string>();
@@ -184,11 +184,11 @@ private static void CheckOutputFiles(
 
                 if (File.Exists(fullPath))
                 {
-                    existingFiles.Add(path);
+                    existingFiles.Add(path!);
 
                     if (File.GetAttributes(fullPath).HasFlag(FileAttributes.ReadOnly))
                     {
-                        readOnlyFiles.Add(path);
+                        readOnlyFiles.Add(path!);
                     }
                 }
             }

src/EFCore.Design/Scaffolding/Metadata/Internal/DatabaseColumnExtensions.cs

@@ -25,7 +25,10 @@ public static class DatabaseColumnExtensions
         ///     doing so can result in application failures when updating to a new Entity Framework Core release.
         /// </summary>
         public static string DisplayName([NotNull] this DatabaseColumn column)
-            => column.Table.DisplayName() + "." + column.Name;
+        {
+            var tablePrefix = column.Table?.DisplayName();
+            return (!string.IsNullOrEmpty(tablePrefix) ? tablePrefix + "." : "") + column.Name;
+        }
 
         /// <summary>
         ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
@@ -35,7 +38,7 @@ public static string DisplayName([NotNull] this DatabaseColumn column)
         /// </summary>
         public static bool IsKeyOrIndex([NotNull] this DatabaseColumn column)
         {
-            var table = column.Table;
+            var table = column.Table!;
 
             if (table.PrimaryKey?.Columns.Contains(column) == true)
             {

src/EFCore.Design/Scaffolding/Metadata/Internal/DatabaseForeignKeyExtensions.cs

@@ -23,6 +23,6 @@ public static class DatabaseForeignKeyExtensions
         ///     doing so can result in application failures when updating to a new Entity Framework Core release.
         /// </summary>
         public static string DisplayName([NotNull] this DatabaseForeignKey foreignKey)
-            => foreignKey.Table.DisplayName() + "(" + string.Join(",", foreignKey.Columns.Select(f => f.Name)) + ")";
+            => foreignKey.Table?.DisplayName() + "(" + string.Join(",", foreignKey.Columns.Select(f => f.Name)) + ")";
     }
 }

src/EFCore.Design/Scaffolding/Metadata/Internal/DatabaseTableExtensions.cs

@@ -22,6 +22,6 @@ public static class DatabaseTableExtensions
         ///     doing so can result in application failures when updating to a new Entity Framework Core release.
         /// </summary>
         public static string DisplayName([NotNull] this DatabaseTable table)
-            => !string.IsNullOrEmpty(table.Schema) ? table.Schema + "." + table.Name : table.Name;
+            => !string.IsNullOrEmpty(table.Schema) ? table.Schema + "." + table.Name : (table.Name ?? "<UNKNOWN>");
     }
 }

src/EFCore.Design/Scaffolding/ScaffoldedFile.cs

@@ -12,27 +12,16 @@ namespace Microsoft.EntityFrameworkCore.Scaffolding
     /// </summary>
     public class ScaffoldedFile
     {
-        /// <summary>
-        ///     Creates a new instance of <see cref="ScaffoldedFile" />.
-        /// </summary>
-        /// <param name="path"> The path of the scaffolded file. </param>
-        /// <param name="code">  The scaffolded code. </param>
-        public ScaffoldedFile([NotNull] string path, [NotNull] string code)
-        {
-            Path = path;
-            Code = code;
-        }
-
         /// <summary>
         ///     Gets or sets the path.
         /// </summary>
         /// <value> The path. </value>
-        public virtual string Path { get; [param: NotNull] set; }
+        public virtual string? Path { get; [param: NotNull] set; }
 
         /// <summary>
         ///     Gets or sets the scaffolded code.
         /// </summary>
         /// <value> The scaffolded code. </value>
-        public virtual string Code { get; [param: NotNull] set; }
+        public virtual string? Code { get; [param: NotNull] set; }
     }
 }

src/EFCore.Design/Scaffolding/ScaffoldedModel.cs

@@ -13,20 +13,11 @@ namespace Microsoft.EntityFrameworkCore.Scaffolding
     /// </summary>
     public class ScaffoldedModel
     {
-        /// <summary>
-        ///     Creates a new instance of <see cref="ScaffoldedModel" />.
-        /// </summary>
-        /// <param name="contextFile"> The scaffolded context file. </param>
-        public ScaffoldedModel([NotNull] ScaffoldedFile contextFile)
-        {
-            ContextFile = contextFile;
-        }
-
         /// <summary>
         ///     Gets or sets the generated file containing the <see cref="DbContext" />.
         /// </summary>
         /// <value> The generated file containing the <see cref="DbContext" />. </value>
-        public virtual ScaffoldedFile ContextFile { get; [param: NotNull] set; }
+        public virtual ScaffoldedFile? ContextFile { get; [param: NotNull] set; }
 
         /// <summary>
         ///     Gets any additional generated files for the model.

src/EFCore.Relational/Scaffolding/Metadata/DatabaseColumn.cs

@@ -1,10 +1,10 @@
 // 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 JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.Infrastructure;
 using Microsoft.EntityFrameworkCore.Metadata;
-using Microsoft.EntityFrameworkCore.Metadata.Internal;
 
 #nullable enable
 
@@ -15,28 +15,15 @@ namespace Microsoft.EntityFrameworkCore.Scaffolding.Metadata
     /// </summary>
     public class DatabaseColumn : Annotatable
     {
-        /// <summary>
-        ///     Creates a new instance of the <see cref="DatabaseColumn" /> class.
-        /// </summary>
-        /// <param name="table"> The table containing this column. </param>
-        /// <param name="name"> The name of the column. </param>
-        /// <param name="storeType"> The store type of the column. </param>
-        public DatabaseColumn([NotNull] DatabaseTable table, [NotNull] string name, [NotNull] string storeType)
-        {
-            Table = table;
-            Name = name;
-            StoreType = storeType;
-        }
-
         /// <summary>
         ///     The table that contains this column.
         /// </summary>
-        public virtual DatabaseTable Table { get; [param: NotNull] set; }
+        public virtual DatabaseTable? Table { get; [param: NotNull] set; }
 
         /// <summary>
         ///     The column name.
         /// </summary>
-        public virtual string Name { get; [param: NotNull] set; }
+        public virtual string? Name { get; [param: NotNull] set; }
 
         /// <summary>
         ///     Indicates whether or not this column can contain <c>NULL</c> values.
@@ -46,7 +33,7 @@ public DatabaseColumn([NotNull] DatabaseTable table, [NotNull] string name, [Not
         /// <summary>
         ///     The database/store type of the column.
         /// </summary>
-        public virtual string StoreType { get; [param: NotNull] set; }
+        public virtual string? StoreType { get; [param: CanBeNull] set; }
 
         /// <summary>
         ///     The default constraint for the column, or <c>null</c> if none.
@@ -82,6 +69,6 @@ public DatabaseColumn([NotNull] DatabaseTable table, [NotNull] string name, [Not
         public virtual ValueGenerated? ValueGenerated { get; set; }
 
         /// <inheritdoc />
-        public override string ToString() => Name;
+        public override string ToString() => Name ?? "<UNKNOWN>";
     }
 }

src/EFCore.Relational/Scaffolding/Metadata/DatabaseForeignKey.cs

@@ -1,6 +1,7 @@
 // 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.Collections.Generic;
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.Infrastructure;
@@ -15,44 +16,26 @@ namespace Microsoft.EntityFrameworkCore.Scaffolding.Metadata
     /// </summary>
     public class DatabaseForeignKey : Annotatable
     {
-        /// <summary>
-        ///     Creates a new instance of the <see cref="DatabaseForeignKey" /> class.
-        /// </summary>
-        /// <param name="table"> The table containing this foreign key constraint. </param>
-        /// <param name="name"> The name of the foreign key constraint. </param>
-        /// <param name="principalTable"> The table to which the columns are constrained. </param>
-        public DatabaseForeignKey(
-            [NotNull] DatabaseTable table,
-            [CanBeNull] string? name,
-            [NotNull] DatabaseTable principalTable)
-        {
-            Table = table;
-            Name = name;
-            PrincipalTable = principalTable;
-            Columns = new List<DatabaseColumn>();
-            PrincipalColumns = new List<DatabaseColumn>();
-        }
-
         /// <summary>
         ///     The table that contains the foreign key constraint.
         /// </summary>
-        public virtual DatabaseTable Table { get; [param: NotNull] set; }
+        public virtual DatabaseTable? Table { get; [param: NotNull] set; }
 
         /// <summary>
         ///     The table to which the columns are constrained.
         /// </summary>
-        public virtual DatabaseTable PrincipalTable { get; [param: NotNull] set; }
+        public virtual DatabaseTable? PrincipalTable { get; [param: NotNull] set; }
 
         /// <summary>
         ///     The ordered list of columns that are constrained.
         /// </summary>
-        public virtual IList<DatabaseColumn> Columns { get; }
+        public virtual IList<DatabaseColumn> Columns { get; } = new List<DatabaseColumn>();
 
         /// <summary>
         ///     The ordered list of columns in the <see cref="PrincipalTable" /> to which the <see cref="Columns" />
         ///     of the foreign key are constrained.
         /// </summary>
-        public virtual IList<DatabaseColumn> PrincipalColumns { get; }
+        public virtual IList<DatabaseColumn> PrincipalColumns { get; } = new List<DatabaseColumn>();
 
         /// <summary>
         ///     The foreign key constraint name.

src/EFCore.Relational/Scaffolding/Metadata/DatabaseIndex.cs

@@ -14,22 +14,10 @@ namespace Microsoft.EntityFrameworkCore.Scaffolding.Metadata
     /// </summary>
     public class DatabaseIndex : Annotatable
     {
-        /// <summary>
-        ///     Creates a new instance of the <see cref="DatabaseIndex" /> class.
-        /// </summary>
-        /// <param name="table"> The table containing this index. </param>
-        /// <param name="name"> The name of the index. </param>
-        public DatabaseIndex([NotNull] DatabaseTable table, [CanBeNull] string? name)
-        {
-            Table = table;
-            Name = name;
-            Columns = new List<DatabaseColumn>();
-        }
-
         /// <summary>
         ///     The table that contains the index.
         /// </summary>
-        public virtual DatabaseTable Table { get; [param: NotNull] set; }
+        public virtual DatabaseTable? Table { get; [param: CanBeNull] set; }
 
         /// <summary>
         ///     The index name.
@@ -39,7 +27,7 @@ public DatabaseIndex([NotNull] DatabaseTable table, [CanBeNull] string? name)
         /// <summary>
         ///     The ordered list of columns that make up the index.
         /// </summary>
-        public virtual IList<DatabaseColumn> Columns { get; }
+        public virtual IList<DatabaseColumn> Columns { get; } = new List<DatabaseColumn>();
 
         /// <summary>
         ///     Indicates whether or not the index constrains uniqueness.

src/EFCore.Relational/Scaffolding/Metadata/DatabasePrimaryKey.cs

@@ -14,22 +14,10 @@ namespace Microsoft.EntityFrameworkCore.Scaffolding.Metadata
     /// </summary>
     public class DatabasePrimaryKey : Annotatable
     {
-        /// <summary>
-        ///     Creates a new instance of the <see cref="DatabasePrimaryKey" /> class.
-        /// </summary>
-        /// <param name="table"> The table on which this primary key is defined. </param>
-        /// <param name="name"> The name of the primary key. </param>
-        public DatabasePrimaryKey([NotNull] DatabaseTable table, [CanBeNull] string? name)
-        {
-            Table = table;
-            Name = name;
-            Columns = new List<DatabaseColumn>();
-        }
-
         /// <summary>
         ///     The table on which the primary key is defined.
         /// </summary>
-        public virtual DatabaseTable Table { get; [param: NotNull] set; }
+        public virtual DatabaseTable? Table { get; [param: CanBeNull] set; }
 
         /// <summary>
         ///     The name of the primary key.
@@ -39,7 +27,7 @@ public DatabasePrimaryKey([NotNull] DatabaseTable table, [CanBeNull] string? nam
         /// <summary>
         ///     The ordered list of columns that make up the primary key.
         /// </summary>
-        public virtual IList<DatabaseColumn> Columns { get; }
+        public virtual IList<DatabaseColumn> Columns { get; } = new List<DatabaseColumn>();
 
         /// <inheritdoc />
         public override string ToString() => Name ?? "<UNKNOWN>";