Design: Stop invoking Startup.ConfigureServices

Part of #8164

Author: bricelam

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

@@ -36,8 +36,7 @@ public DatabaseOperations(
             _projectDir = projectDir;
             _rootNamespace = rootNamespace;
 
-            var startup = new StartupInvoker(reporter, startupAssembly);
-            _servicesBuilder = new DesignTimeServicesBuilder(startup);
+            _servicesBuilder = new DesignTimeServicesBuilder(startupAssembly);
         }
 
         public virtual Task<ReverseEngineerFiles> ScaffoldContextAsync(

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

@@ -22,7 +22,6 @@ public class DbContextOperations
         private readonly IOperationReporter _reporter;
         private readonly Assembly _assembly;
         private readonly Assembly _startupAssembly;
-        private readonly IServiceProvider _runtimeServices;
 
         // This obsolete constructor maintains compatibility with Scaffolding
         public DbContextOperations(
@@ -47,9 +46,6 @@ public DbContextOperations(
             _reporter = reporter;
             _assembly = assembly;
             _startupAssembly = startupAssembly;
-
-            var startup = new StartupInvoker(reporter, startupAssembly);
-            _runtimeServices = startup.ConfigureServices();
         }
 
         public virtual void DropDatabase([CanBeNull] string contextType)
@@ -114,25 +110,15 @@ where i.GetTypeInfo().IsGenericType
                 }
             }
 
-            // Look for DbContext classes registered in the service provider
-            var registeredContexts = _runtimeServices.GetServices<DbContextOptions>()
-                .Select(o => o.ContextType);
-            foreach (var context in registeredContexts.Where(c => !contexts.ContainsKey(c)))
-            {
-                contexts.Add(
-                    context,
-                    FindContextFactory(context) ?? (() => (DbContext)ActivatorUtilities.GetServiceOrCreateInstance(_runtimeServices, context)));
-            }
-
             // Look for DbContext classes in assemblies
             var types = _startupAssembly.GetConstructableTypes()
                 .Concat(_assembly.GetConstructableTypes())
-                .Select(i => i.AsType())
                 .ToList();
-            var contextTypes = types.Where(t => typeof(DbContext).IsAssignableFrom(t))
+            var contextTypes = types.Where(t => typeof(DbContext).GetTypeInfo().IsAssignableFrom(t)).Select(
+                    t => t.AsType())
                 .Concat(
-                    types.Where(t => typeof(Migration).IsAssignableFrom(t))
-                        .Select(t => t.GetTypeInfo().GetCustomAttribute<DbContextAttribute>()?.ContextType)
+                    types.Where(t => typeof(Migration).GetTypeInfo().IsAssignableFrom(t))
+                        .Select(t => t.GetCustomAttribute<DbContextAttribute>()?.ContextType)
                         .Where(t => t != null))
                 .Distinct();
             foreach (var context in contextTypes.Where(c => !contexts.ContainsKey(c)))
@@ -173,14 +159,13 @@ private Func<DbContext> FindContextFactory(Type contextType)
             var factoryInterface = typeof(IDbContextFactory<>).MakeGenericType(contextType).GetTypeInfo();
             var factory = contextType.GetTypeInfo().Assembly.GetConstructableTypes()
                 .Where(t => factoryInterface.IsAssignableFrom(t))
-                .Select(t => t.AsType())
                 .FirstOrDefault();
             if (factory == null)
             {
                 return null;
             }
 
-            return () => ((IDbContextFactory<DbContext>)Activator.CreateInstance(factory)).Create(
+            return () => ((IDbContextFactory<DbContext>)Activator.CreateInstance(factory.AsType())).Create(
                 Array.Empty<string>());
         }
 

src/EFCore.Design/Design/Internal/DesignTimeServicesBuilder.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.IO;
+using System.Linq;
 using System.Reflection;
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.Infrastructure;
@@ -24,15 +25,15 @@ namespace Microsoft.EntityFrameworkCore.Design.Internal
     /// </summary>
     public class DesignTimeServicesBuilder
     {
-        private readonly StartupInvoker _startup;
+        private readonly Assembly _startupAssembly;
 
         /// <summary>
         ///     This API supports the Entity Framework Core infrastructure and is not intended to be used
         ///     directly from your code. This API may change or be removed in future releases.
         /// </summary>
-        public DesignTimeServicesBuilder([NotNull] StartupInvoker startupInvoker)
+        public DesignTimeServicesBuilder([NotNull] Assembly startupAssembly)
         {
-            _startup = startupInvoker;
+            _startupAssembly = startupAssembly;
         }
 
         /// <summary>
@@ -80,7 +81,7 @@ protected virtual IServiceCollection ConfigureServices([NotNull] IServiceCollect
                 .AddLogging();
 
         private IServiceCollection ConfigureProviderServices(string provider, IServiceCollection services, bool throwOnError = false)
-            => _startup.ConfigureDesignTimeServices(GetProviderDesignTimeServices(provider, throwOnError), services);
+            => ConfigureDesignTimeServices(GetProviderDesignTimeServices(provider, throwOnError), services);
 
         /// <summary>
         ///     This API supports the Entity Framework Core infrastructure and is not intended to be used
@@ -105,7 +106,13 @@ protected virtual IServiceCollection ConfigureContextServices(
                 .AddTransient(_ => contextServices.GetService<IModel>());
 
         private IServiceCollection ConfigureUserServices(IServiceCollection services)
-            => _startup.ConfigureDesignTimeServices(services);
+        {
+            var designTimeServicesType = _startupAssembly.GetLoadableDefinedTypes()
+                .Where(t => typeof(IDesignTimeServices).GetTypeInfo().IsAssignableFrom(t)).Select(t => t.AsType())
+                .FirstOrDefault();
+
+            return ConfigureDesignTimeServices(designTimeServicesType, services);
+        }
 
         private Type GetProviderDesignTimeServices(string provider, bool throwOnError)
         {
@@ -160,5 +167,18 @@ private Type GetProviderDesignTimeServices(string provider, bool throwOnError)
                 throwOnError: true,
                 ignoreCase: false);
         }
+
+        private static IServiceCollection ConfigureDesignTimeServices(
+            Type designTimeServicesType,
+            IServiceCollection services)
+        {
+            if (designTimeServicesType != null)
+            {
+                var designTimeServices = (IDesignTimeServices)Activator.CreateInstance(designTimeServicesType);
+                designTimeServices.ConfigureDesignTimeServices(services);
+            }
+
+            return services;
+        }
     }
 }

src/EFCore.Design/Design/Internal/HostingEnvironment.cs

@@ -48,8 +48,7 @@ public MigrationsOperations(
                 assembly,
                 startupAssembly);
 
-            var startup = new StartupInvoker(reporter, startupAssembly);
-            _servicesBuilder = new DesignTimeServicesBuilder(startup);
+            _servicesBuilder = new DesignTimeServicesBuilder(startupAssembly);
         }
 
         public virtual MigrationFiles AddMigration(

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

@@ -14,9 +14,6 @@
   <ItemGroup>
     <ProjectReference Include="..\EFCore.Relational.Design\EFCore.Relational.Design.csproj" />
   </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.Hosting.Abstractions" Version="$(AspNetCoreVersion)" />
-  </ItemGroup>
   <ItemGroup Condition="'$(TargetFramework)' == 'netstandard1.3'">
     <PackageReference Include="System.Collections.NonGeneric" Version="$(CoreFxVersion)" />
   </ItemGroup>

src/EFCore.Design/Design/Internal/StartupInvoker.cs

@@ -26,8 +26,7 @@ public sealed class DesignTimeProviderServicesAttribute : Attribute
         /// </summary>
         /// <param name="typeName">
         ///     The name of the type that can be used to add the database providers design time services to a <see cref="ServiceCollection" />.
-        ///     This type should contain a method with the following signature
-        ///     <code>public IServiceCollection ConfigureDesignTimeServices(IServiceCollection serviceCollection)</code>.
+        ///     This type should implement <see cref="IDesignTimeServices" />.
         /// </param>
         /// <param name="assemblyName">
         ///     The name of the assembly that contains the design time services.
@@ -49,8 +48,7 @@ public DesignTimeProviderServicesAttribute(
 
         /// <summary>
         ///     Gets the name of the type that can be used to add the database providers design time services to a <see cref="ServiceCollection" />.
-        ///     This type should contain a method with the following signature
-        ///     <code>public IServiceCollection ConfigureDesignTimeServices(IServiceCollection serviceCollection)</code>.
+        ///     This type should implement <see cref="IDesignTimeServices"/>.
         /// </summary>
         public string TypeName { get; }