From 0bb279287b04eb5d990f6508d6bbeec5b024a291 Mon Sep 17 00:00:00 2001
From: Dzmitry Safarau <DSilencea@gmail.com>
Date: Wed, 12 Sep 2018 16:10:53 +0300
Subject: [PATCH] Implemented #13088: Add ApplyConfiguration() overloads to
 ModelBuilder that scans assemblies.

---
 src/EFCore/ModelBuilderExtensions.cs          |  55 +++++++++
 ...EntityTypeConfigurationAssemblyScanTest.cs | 108 ++++++++++++++++++
 2 files changed, 163 insertions(+)
 create mode 100644 src/EFCore/ModelBuilderExtensions.cs
 create mode 100644 test/EFCore.Tests/ModelBuilding/IEntityTypeConfigurationAssemblyScanTest.cs

diff --git a/src/EFCore/ModelBuilderExtensions.cs b/src/EFCore/ModelBuilderExtensions.cs
new file mode 100644
index 00000000000..1f41d884d7c
--- /dev/null
+++ b/src/EFCore/ModelBuilderExtensions.cs
@@ -0,0 +1,55 @@
+// 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.Linq;
+using System.Reflection;
+
+namespace Microsoft.EntityFrameworkCore
+{
+    /// <summary>
+    /// Entity Framework <see cref="ModelBuilder"/> related extension methods.
+    /// </summary>
+    public static class ModelBuilderExtensions
+    {
+        /// <summary>
+        ///     Applies configuration from all <see cref="IEntityTypeConfiguration{TEntity}" /> instances that are defined in provided assembly.
+        /// </summary>
+        /// <param name="modelBuilder"> The instance of <see cref="ModelBuilder"/> to modify</param>
+        /// <param name="assembly"> The assembly to scan </param>
+        /// <param name="predicate"> Optional predicate to filter types within the assembly</param>
+        /// <returns>
+        ///     The same <see cref="ModelBuilder" /> instance so that additional configuration calls can be chained.
+        /// </returns>
+        public static ModelBuilder ApplyEntityTypeConfigurations(this ModelBuilder modelBuilder, Assembly assembly, Func<Type, bool> predicate = null)
+        {
+            var method = typeof(ModelBuilder)
+                .GetMethods()
+                .Single(
+                    e => e.Name == nameof(modelBuilder.ApplyConfiguration)
+                         && e.ContainsGenericParameters
+                         && e.GetParameters().SingleOrDefault()?.ParameterType?.GetGenericTypeDefinition() == typeof(IEntityTypeConfiguration<>));
+            foreach (var type in assembly.GetTypes())
+            {
+                // Only accept types that contain a parameterless constrictor, are not abstract and satisfy a predicate if it was used.
+                if (type.GetConstructor(Type.EmptyTypes) == null || type.IsAbstract || (!predicate?.Invoke(type) ?? false))
+                {
+                    continue;
+                }
+                var @interface = type.GetInterfaces().FirstOrDefault(
+                    i => i.IsGenericType && i.GetGenericTypeDefinition() == typeof(IEntityTypeConfiguration<>));
+                if (@interface == null)
+                {
+                    continue;
+                }
+
+
+                var configuration = Activator.CreateInstance(type);
+                var target = method.MakeGenericMethod(@interface.GenericTypeArguments[0]);
+                target.Invoke(modelBuilder, new[] { configuration });
+            }
+
+            return modelBuilder;
+        }
+    }
+}
diff --git a/test/EFCore.Tests/ModelBuilding/IEntityTypeConfigurationAssemblyScanTest.cs b/test/EFCore.Tests/ModelBuilding/IEntityTypeConfigurationAssemblyScanTest.cs
new file mode 100644
index 00000000000..d1535e1abf2
--- /dev/null
+++ b/test/EFCore.Tests/ModelBuilding/IEntityTypeConfigurationAssemblyScanTest.cs
@@ -0,0 +1,108 @@
+// 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.Linq;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
+using Microsoft.EntityFrameworkCore.TestUtilities;
+using Xunit;
+
+namespace Microsoft.EntityFrameworkCore.ModelBuilding
+{
+    public abstract partial class ModelBuilderTest
+    {
+        private static bool _customerConfigurationCalled;
+        private static bool _customerConfiguration2Called;
+        private static bool _abstractClassCalled;
+        private static bool _abstractClassImplCalled;
+        
+        protected ModelBuilderTest()
+        {
+            _customerConfigurationCalled = false;
+            _customerConfiguration2Called = false;
+            _abstractClassCalled = false;
+            _abstractClassImplCalled = false;
+        }
+
+        public class ModelBuilderExtensionsTest : ModelBuilderTest
+        {
+            [Fact]
+            public void Should_scan_assemblies()
+            {
+                var builder = InMemoryTestHelpers.Instance.CreateConventionBuilder();
+                builder.ApplyEntityTypeConfigurations(typeof(IEntityTypeConfigurationTest).Assembly);
+
+                Assert.True(_customerConfigurationCalled);
+                Assert.True(_customerConfiguration2Called);
+                Assert.False(_abstractClassCalled);
+                Assert.True(_abstractClassImplCalled);
+            }
+
+            [Fact]
+            public void Should_support_filtering()
+            {
+                var builder = InMemoryTestHelpers.Instance.CreateConventionBuilder();
+                builder.ApplyEntityTypeConfigurations(typeof(ModelBuilderExtensionsTest).Assembly, type => type.Name == "CustomerConfiguration");
+
+                Assert.True(_customerConfigurationCalled);
+                Assert.False(_customerConfiguration2Called);
+                Assert.False(_abstractClassCalled);
+                Assert.False(_abstractClassImplCalled);
+
+                var entityType = builder.Model.FindEntityType(typeof(Customer));
+                Assert.Equal(nameof(Customer.AlternateKey), entityType.GetKeys().Single().Properties.Single().Name);
+                Assert.Equal(200, entityType.FindProperty(nameof(Customer.Name)).GetMaxLength());
+            }
+
+            [Fact]
+            public void Should_skip_abstract_classes()
+            {
+                var builder = InMemoryTestHelpers.Instance.CreateConventionBuilder();
+                builder.ApplyEntityTypeConfigurations(typeof(ModelBuilderExtensionsTest).Assembly, type => type.Name == "AbstractCustomerConfiguration");
+
+                Assert.False(_customerConfigurationCalled);
+                Assert.False(_customerConfiguration2Called);
+                Assert.False(_abstractClassCalled);
+                Assert.False(_abstractClassImplCalled);
+            }
+
+            private class CustomerConfiguration : IEntityTypeConfiguration<Customer>
+            {
+                public void Configure(EntityTypeBuilder<Customer> builder)
+                {
+                    builder.HasKey(c => c.AlternateKey);
+
+                    builder.Property(c => c.Name).HasMaxLength(200);
+
+                    _customerConfigurationCalled = true;
+                }
+            }
+
+            private class CustomerConfiguration2 : IEntityTypeConfiguration<Customer>
+            {
+                public void Configure(EntityTypeBuilder<Customer> builder)
+                {
+                    builder.Property(c => c.Name).HasMaxLength(1000);
+
+                    _customerConfiguration2Called = true;
+                }
+            }
+
+            private abstract class AbstractCustomerConfiguration : IEntityTypeConfiguration<Customer>
+            {
+                public virtual void Configure(EntityTypeBuilder<Customer> builder)
+                {
+                    _abstractClassCalled = true;
+                }
+            }
+
+            private class AbstractCustomerConfigurationImpl : AbstractCustomerConfiguration
+            {
+                public override void Configure(EntityTypeBuilder<Customer> builder)
+                {
+                    _abstractClassImplCalled = true;
+                }
+            }
+        }
+    }
+}