Add commands to create compiled models (dotnet#24906)

Warn when using and old model
Enable NRT-enabled code generation
Remove the need to call FinalizeModel before UseModel
Split out the boilerplate part of the compiled model

Fixes dotnet#1906

src/EFCore.Design/Design/DbContextActivator.cs

@@ -50,6 +50,10 @@ public static DbContext CreateInstance(
                     new OperationReporter(reportHandler),
                     contextType.Assembly,
                     startupAssembly ?? contextType.Assembly,
+                    projectDir: "",
+                    rootNamespace: null,
+                    language: "C#",
+                    nullable: false,
                     args: args ?? Array.Empty<string>())
                 .CreateContext(contextType.FullName!);
         }

src/EFCore.Design/Design/DesignTimeServiceCollectionExtensions.cs

@@ -60,6 +60,7 @@ public static IServiceCollection AddEntityFrameworkDesignTimeServices(
                     .TryAddSingleton<IModelCodeGeneratorSelector, ModelCodeGeneratorSelector>()
                     .TryAddSingleton<ICompiledModelCodeGenerator, CSharpRuntimeModelCodeGenerator>()
                     .TryAddSingleton<ICompiledModelCodeGeneratorSelector, CompiledModelCodeGeneratorSelector>()
+                    .TryAddSingleton<ICompiledModelScaffolder, CompiledModelScaffolder>()
                     .TryAddSingleton<INamedConnectionStringResolver>(
                         new DesignTimeConnectionStringResolver(applicationServiceProviderAccessor))
                     .TryAddSingleton<IPluralizer, HumanizerPluralizer>()

src/EFCore.Design/Design/Internal/DbContextOperations.cs

@@ -3,12 +3,15 @@
 
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Reflection;
 using Microsoft.EntityFrameworkCore.Infrastructure;
 using Microsoft.EntityFrameworkCore.Infrastructure.Internal;
 using Microsoft.EntityFrameworkCore.Internal;
+using Microsoft.EntityFrameworkCore.Metadata;
 using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Scaffolding;
 using Microsoft.EntityFrameworkCore.Storage;
 using Microsoft.EntityFrameworkCore.Utilities;
 using Microsoft.Extensions.DependencyInjection;
@@ -27,8 +30,13 @@ public class DbContextOperations
         private readonly IOperationReporter _reporter;
         private readonly Assembly _assembly;
         private readonly Assembly _startupAssembly;
+        private readonly string _projectDir;
+        private readonly string? _rootNamespace;
+        private readonly string? _language;
+        private readonly bool _nullable;
         private readonly string[] _args;
         private readonly AppServiceProviderFactory _appServicesFactory;
+        private readonly DesignTimeServicesBuilder _servicesBuilder;
 
         /// <summary>
         ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
@@ -40,8 +48,20 @@ public DbContextOperations(
             IOperationReporter reporter,
             Assembly assembly,
             Assembly startupAssembly,
+            string projectDir,
+            string? rootNamespace,
+            string? language,
+            bool nullable,
             string[]? args)
-            : this(reporter, assembly, startupAssembly, args, new AppServiceProviderFactory(startupAssembly, reporter))
+            : this(reporter,
+                  assembly,
+                  startupAssembly,
+                  projectDir,
+                  rootNamespace,
+                  language,
+                  nullable,
+                  args,
+                  new AppServiceProviderFactory(startupAssembly, reporter))
         {
         }
 
@@ -55,18 +75,28 @@ protected DbContextOperations(
             IOperationReporter reporter,
             Assembly assembly,
             Assembly startupAssembly,
+            string projectDir,
+            string? rootNamespace,
+            string? language,
+            bool nullable,
             string[]? args,
             AppServiceProviderFactory appServicesFactory)
         {
             Check.NotNull(reporter, nameof(reporter));
             Check.NotNull(assembly, nameof(assembly));
             Check.NotNull(startupAssembly, nameof(startupAssembly));
+            Check.NotNull(projectDir, nameof(projectDir));
 
             _reporter = reporter;
             _assembly = assembly;
             _startupAssembly = startupAssembly;
+            _projectDir = projectDir;
+            _rootNamespace = rootNamespace;
+            _language = language;
+            _nullable = nullable;
             _args = args ?? Array.Empty<string>();
             _appServicesFactory = appServicesFactory;
+            _servicesBuilder = new DesignTimeServicesBuilder(assembly, startupAssembly, reporter, _args);
         }
 
         /// <summary>
@@ -102,6 +132,83 @@ public virtual string ScriptDbContext(string? contextType)
             return context.Database.GenerateCreateScript();
         }
 
+        /// <summary>
+        ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
+        ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
+        ///     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 IReadOnlyList<string> Optimize(string? outputDir, string? modelNamespace, string? contextType)
+        {
+            using var context = CreateContext(contextType);
+
+            var services = _servicesBuilder.Build(context);
+            var scaffolder = services.GetRequiredService<ICompiledModelScaffolder>();
+
+            outputDir = outputDir != null
+                ? Path.GetFullPath(Path.Combine(_projectDir, outputDir))
+                : _projectDir;
+
+            var finalModelNamespace = modelNamespace ?? GetNamespaceFromOutputPath(outputDir) ?? "";
+
+            var scaffoldedModel = scaffolder.ScaffoldModel(
+                context.GetService<IDesignTimeModel>().Model,
+                outputDir,
+                new CompiledModelCodeGenerationOptions
+                {
+                    ContextType = context.GetType(),
+                    ModelNamespace = finalModelNamespace,
+                    Language = _language,
+                    UseNullableReferenceTypes = _nullable
+                });
+
+            var fullName = context.GetType().ShortDisplayName() + "Model";
+            if (!string.IsNullOrEmpty(modelNamespace))
+            {
+                fullName = modelNamespace + "." + fullName;
+            }
+
+            _reporter.WriteInformation(DesignStrings.CompiledModelGenerated($"options.UseModel({fullName}.Instance)"));
+
+            var cacheKeyFactory = context.GetService<IModelCacheKeyFactory>();
+            if (!(cacheKeyFactory is ModelCacheKeyFactory))
+            {
+                _reporter.WriteWarning(DesignStrings.CompiledModelCustomCacheKeyFactory(cacheKeyFactory.GetType().ShortDisplayName()));
+            }
+
+            return scaffoldedModel;
+        }
+
+        private string? GetNamespaceFromOutputPath(string directoryPath)
+        {
+            var subNamespace = SubnamespaceFromOutputPath(_projectDir, directoryPath);
+            return string.IsNullOrEmpty(subNamespace)
+                ? _rootNamespace
+                : string.IsNullOrEmpty(_rootNamespace)
+                    ? subNamespace
+                    : _rootNamespace + "." + subNamespace;
+        }
+
+        // if outputDir is a subfolder of projectDir, then use each subfolder as a subnamespace
+        // --output-dir $(projectFolder)/A/B/C
+        // => "namespace $(rootnamespace).A.B.C"
+        private static string? SubnamespaceFromOutputPath(string projectDir, string outputDir)
+        {
+            if (!outputDir.StartsWith(projectDir, StringComparison.Ordinal))
+            {
+                return null;
+            }
+
+            var subPath = outputDir.Substring(projectDir.Length);
+
+            return !string.IsNullOrWhiteSpace(subPath)
+                ? string.Join(
+                    ".",
+                    subPath.Split(
+                        new[] { Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar }, StringSplitOptions.RemoveEmptyEntries))
+                : null;
+        }
+
         /// <summary>
         ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
         ///     the same compatibility standards as public APIs. It may be changed or removed without notice in

src/EFCore.Design/Design/Internal/MigrationsOperations.cs

@@ -66,6 +66,10 @@ public MigrationsOperations(
                 reporter,
                 assembly,
                 startupAssembly,
+                projectDir,
+                rootNamespace,
+                language,
+                nullable,
                 _args);
 
             _servicesBuilder = new DesignTimeServicesBuilder(assembly, startupAssembly, reporter, _args);

src/EFCore.Design/Design/OperationExecutor.cs

@@ -120,6 +120,10 @@ private DbContextOperations ContextOperations
                     _reporter,
                     Assembly,
                     StartupAssembly,
+                    _projectDir,
+                    _rootNamespace,
+                    _language,
+                    _nullable,
                     _designArgs);
 
         private DatabaseOperations DatabaseOperations
@@ -480,6 +484,41 @@ private IEnumerable<IDictionary> GetMigrationsImpl(
                 });
         }
 
+        /// <summary>
+        ///     Represents an operation to generate a compiled model from the DbContext.
+        /// </summary>
+        public class Optimize : OperationBase
+        {
+            /// <summary>
+            ///     <para>Initializes a new instance of the <see cref="Optimize" /> class.</para>
+            ///     <para>The arguments supported by <paramref name="args" /> are:</para>
+            ///     <para><c>outputDir</c>--The directory to put files in. Paths are relative to the project directory.</para>
+            ///     <para><c>modelNamespace</c>--Specify to override the namespace of the generated model.</para>
+            ///     <para><c>contextType</c>--The <see cref="DbContext" /> to use.</para>
+            /// </summary>
+            /// <param name="executor"> The operation executor. </param>
+            /// <param name="resultHandler"> The <see cref="IOperationResultHandler" />. </param>
+            /// <param name="args"> The operation arguments. </param>
+            public Optimize(
+                OperationExecutor executor,
+                IOperationResultHandler resultHandler,
+                IDictionary args)
+                : base(resultHandler)
+            {
+                Check.NotNull(executor, nameof(executor));
+                Check.NotNull(args, nameof(args));
+
+                var outputDir = (string?)args["outputDir"];
+                var modelNamespace = (string?)args["modelNamespace"];
+                var contextType = (string?)args["contextType"];
+
+                Execute(() => executor.OptimizeImpl(outputDir, modelNamespace, contextType));
+            }
+        }
+
+        private IReadOnlyList<string> OptimizeImpl(string? outputDir, string? modelNamespace, string? contextType)
+            => ContextOperations.Optimize(outputDir, modelNamespace, contextType);
+
         /// <summary>
         ///     Represents an operation to scaffold a <see cref="DbContext" /> and entity types for a database.
         /// </summary>

src/EFCore.Design/Migrations/Internal/SnapshotModelProcessor.cs

@@ -79,11 +79,6 @@ public SnapshotModelProcessor(
                 }
             }
 
-            if (model is IMutableModel mutableModel)
-            {
-                model = mutableModel.FinalizeModel();
-            }
-
             return _modelRuntimeInitializer.Initialize((IModel)model, designTime: true, validationLogger: null);
         }
 

src/EFCore.Design/Properties/DesignStrings.resx

@@ -135,9 +135,15 @@
   <data name="CompiledModelConstructorBinding" xml:space="preserve">
     <value>The entity type '{entityType}' has a custom constructor binding. This is usually caused by using proxies. Compiled model can't be generated, because dynamic proxy types are not supported. If you are not using proxies configure the custom constructor binding in '{customize}' in a partial '{className}' class instead.</value>
   </data>
+  <data name="CompiledModelCustomCacheKeyFactory" xml:space="preserve">
+    <value>The context is configured to use a custom model cache key factory '{factoryType}', this usually indicates that the produced model can change between context instances. To preserve this behavior manually modify the generated compiled model source code.</value>
+  </data>
   <data name="CompiledModelDefiningQuery" xml:space="preserve">
     <value>The entity type '{entityType}' has a defining query configured. Compiled model can't be generated, because defining queries are not supported.</value>
   </data>
+  <data name="CompiledModelGenerated" xml:space="preserve">
+    <value>Successfully generated a compiled model, to use it call '{optionsCall}'. Run this command again when the model is modified.</value>
+  </data>
   <data name="CompiledModelQueryFilter" xml:space="preserve">
     <value>The entity type '{entityType}' has a query filter configured. Compiled model can't be generated, because query filters are not supported.</value>
   </data>

src/EFCore.Design/Scaffolding/CompiledModelCodeGenerationOptions.cs

@@ -27,5 +27,11 @@ public class CompiledModelCodeGenerationOptions
         /// </summary>
         /// <value> The programming language to scaffold for. </value>
         public virtual string? Language { get; set; }
+
+        /// <summary>
+        ///     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 UseNullableReferenceTypes  { get; set; }
     }
 }

src/EFCore.Design/Scaffolding/ICompiledModelScaffolder.cs

@@ -0,0 +1,26 @@
+// 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.Collections.Generic;
+using Microsoft.EntityFrameworkCore.Metadata;
+
+namespace Microsoft.EntityFrameworkCore.Scaffolding
+{
+    /// <summary>
+    ///     Used to scaffold a compiled model from a model.
+    /// </summary>
+    public interface ICompiledModelScaffolder
+    {
+        /// <summary>
+        ///     Scaffolds a compiled model from a model and saves it to disk.
+        /// </summary>
+        /// <param name="model"> The model. </param>
+        /// <param name="outputDir"> The output directory. </param>
+        /// <param name="options"> The options to use when generating code for the model. </param>
+        /// <returns> The scaffolded model files. </returns>
+        IReadOnlyList<string> ScaffoldModel(
+            IModel model,
+            string outputDir,
+            CompiledModelCodeGenerationOptions options);
+    }
+}