Further simplify upgrader

src/Umbraco.Core/Migrations/Upgrade/UmbracoUpgrader.cs

@@ -15,8 +15,12 @@ namespace Umbraco.Core.Migrations.Upgrade
     {
         private PostMigrationCollection _postMigrations;
 
-        /// <inheritdoc />
-        protected override MigrationPlan CreatePlan() => new UmbracoPlan();
+        /// <summary>
+        /// Initializes a new instance of the <see ref="UmbracoUpgrader" /> class.
+        /// </summary>
+        public UmbracoUpgrader()
+            : base(new UmbracoPlan())
+        { }
 
         /// <summary>
         /// Executes.

src/Umbraco.Core/Migrations/Upgrade/Upgrader.cs

@@ -6,11 +6,17 @@ using Umbraco.Core.Services;
 namespace Umbraco.Core.Migrations.Upgrade
 {
     /// <summary>
-    /// Provides an abstract base class for creating upgraders.
+    /// Represents an upgrader.
     /// </summary>
-    public abstract class Upgrader
+    public class Upgrader
     {
-        private MigrationPlan _plan;
+        /// <summary>
+        /// Initializes a new instance of the <see ref="Upgrader"/> class.
+        /// </summary>
+        public Upgrader(MigrationPlan plan)
+        {
+            Plan = plan;
+        }
 
         /// <summary>
         /// Gets the name of the migration plan.
@@ -20,12 +26,7 @@ namespace Umbraco.Core.Migrations.Upgrade
         /// <summary>
         /// Gets the migration plan.
         /// </summary>
-        public MigrationPlan Plan => _plan ?? (_plan = CreatePlan());
-
-        /// <summary>
-        /// Creates the migration plan.
-        /// </summary>
-        protected abstract MigrationPlan CreatePlan();
+        public MigrationPlan Plan { get; }
 
         /// <summary>
         /// Gets the key for the state value.

src/Umbraco.Tests/Migrations/AdvancedMigrationTests.cs

@@ -5,6 +5,7 @@ using NUnit.Framework;
 using Umbraco.Core.Logging;
 using Umbraco.Core.Migrations;
 using Umbraco.Core.Migrations.Install;
+using Umbraco.Core.Migrations.Upgrade;
 using Umbraco.Core.Persistence.DatabaseModelDefinitions;
 using Umbraco.Core.Persistence.Dtos;
 using Umbraco.Core.Services;
@@ -34,7 +35,7 @@ namespace Umbraco.Tests.Migrations
 
             using (var scope = ScopeProvider.CreateScope())
             {
-                var upgrader = new MigrationTests.TestUpgrader(
+                var upgrader = new Upgrader(
                     new MigrationPlan("test")
                         .From(string.Empty)
                         .To<CreateTableOfTDtoMigration>("done"));
@@ -72,7 +73,7 @@ namespace Umbraco.Tests.Migrations
 
             using (var scope = ScopeProvider.CreateScope())
             {
-                var upgrader = new MigrationTests.TestUpgrader(
+                var upgrader = new Upgrader(
                     new MigrationPlan("test")
                         .From(string.Empty)
                         .To<CreateTableOfTDtoMigration>("a")
@@ -108,7 +109,7 @@ namespace Umbraco.Tests.Migrations
 
             using (var scope = ScopeProvider.CreateScope())
             {
-                var upgrader = new MigrationTests.TestUpgrader(
+                var upgrader = new Upgrader(
                     new MigrationPlan("test")
                         .From(string.Empty)
                         .To<CreateTableOfTDtoMigration>("a")
@@ -145,7 +146,7 @@ namespace Umbraco.Tests.Migrations
 
             using (var scope = ScopeProvider.CreateScope())
             {
-                var upgrader = new MigrationTests.TestUpgrader(
+                var upgrader = new Upgrader(
                     new MigrationPlan("test")
                         .From(string.Empty)
                         .To<CreateTableOfTDtoMigration>("a")
@@ -180,7 +181,7 @@ namespace Umbraco.Tests.Migrations
 
             using (var scope = ScopeProvider.CreateScope())
             {
-                var upgrader = new MigrationTests.TestUpgrader(
+                var upgrader = new Upgrader(
                     new MigrationPlan("test")
                         .From(string.Empty)
                         .To<CreateTableOfTDtoMigration>("a")

src/Umbraco.Tests/Migrations/MigrationTests.cs

@@ -1,10 +1,8 @@
 using System;
-using System.Configuration;
 using System.Data;
 using Moq;
 using NUnit.Framework;
 using Semver;
-using Umbraco.Core.Configuration;
 using Umbraco.Core.Events;
 using Umbraco.Core.Migrations;
 using Umbraco.Core.Migrations.Upgrade;
@@ -18,22 +16,7 @@ namespace Umbraco.Tests.Migrations
     [TestFixture]
     public class MigrationTests
     {
-        public class TestUpgrader : Upgrader
-        {
-            private readonly MigrationPlan _plan;
-
-            public TestUpgrader(MigrationPlan plan)
-            {
-                _plan = plan;
-            }
-
-            protected override MigrationPlan CreatePlan()
-            {
-                return _plan;
-            }
-        }
-
-        public class TestUpgraderWithPostMigrations : TestUpgrader
+        public class TestUpgraderWithPostMigrations : Upgrader
         {
             private PostMigrationCollection _postMigrations;