Tools: Add Revert option to Remove-Migration

Resolves #1972

Also updated T4 template for string resources generation. It had some weird issues.

Did manual verification with 1 or more migrations using PMC & dotnet ef both.

samples/OracleProvider/src/OracleProvider/Properties/OracleStrings.resx

@@ -179,7 +179,7 @@
   <data name="LogFoundTable" xml:space="preserve">
     <value>Found table with name: {name}.</value>
     <comment>Debug OracleEventId.TableFound string</comment>
-  </data> 
+  </data>
   <data name="LogFoundIndex" xml:space="preserve">
     <value>Found index with name: {indexName}, table: {tableName}, is unique: {isUnique}.</value>
     <comment>Debug OracleEventId.IndexFound string string bool</comment>
@@ -195,5 +195,8 @@
   <data name="LogPrincipalColumnNotFound" xml:space="preserve">
     <value>For foreign key {foreignKeyName} on table {tableName}, unable to find the column called {principalColumnName} on the foreign key's principal table, {principaltableName}. Skipping foreign key.</value>
     <comment>Warning OracleEventId.ForeignKeyPrincipalColumnMissingWarning string string string string</comment>
-  </data> 
+  </data>
+  <data name="InvalidTableToIncludeInScaffolding" xml:space="preserve">
+    <value>The specified table '{table}' is not valid. Specify tables using the format '[schema].[table]'.</value>
+  </data>
 </root>

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

@@ -105,7 +105,11 @@ private string SubnamespaceFromOutputPath(string outputDir)
             var subPath = outputDir.Substring(_projectDir.Length);
 
             return !string.IsNullOrWhiteSpace(subPath)
-                ? string.Join(".", subPath.Split(new[] { Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar }, StringSplitOptions.RemoveEmptyEntries))
+                ? string.Join(
+                    ".",
+                    subPath.Split(
+                        new[] { Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar },
+                        StringSplitOptions.RemoveEmptyEntries))
                 : null;
         }
 
@@ -176,7 +180,7 @@ public virtual void UpdateDatabase(
         ///     directly from your code. This API may change or be removed in future releases.
         /// </summary>
         public virtual MigrationFiles RemoveMigration(
-            [CanBeNull] string contextType, bool force)
+            [CanBeNull] string contextType, bool force, bool revert)
         {
             using (var context = _contextOperations.CreateContext(contextType))
             {
@@ -186,7 +190,7 @@ public virtual MigrationFiles RemoveMigration(
 
                 var scaffolder = services.GetRequiredService<MigrationsScaffolder>();
 
-                var files = scaffolder.RemoveMigration(_projectDir, _rootNamespace, force, _language);
+                var files = scaffolder.RemoveMigration(_projectDir, _rootNamespace, force, revert, _language);
 
                 _reporter.WriteInformation(DesignStrings.Done);
 

src/EFCore.Design/Design/OperationExecutor.cs

@@ -295,15 +295,16 @@ public RemoveMigration(
 
                 var contextType = (string)args["contextType"];
                 var force = (bool)args["force"];
+                var revert = (bool)args["revert"];
 
-                Execute(() => executor.RemoveMigrationImpl(contextType, force));
+                Execute(() => executor.RemoveMigrationImpl(contextType, force, revert));
             }
         }
 
-        private IDictionary RemoveMigrationImpl([CanBeNull] string contextType, bool force)
+        private IDictionary RemoveMigrationImpl([CanBeNull] string contextType, bool force, bool revert)
         {
             var files = _migrationsOperations.Value
-                .RemoveMigration(contextType, force);
+                .RemoveMigration(contextType, force, revert);
 
             return new Hashtable
             {

src/EFCore.Design/Migrations/Design/MigrationsScaffolder.cs

@@ -206,21 +206,23 @@ protected virtual string GetSubNamespace([NotNull] string rootNamespace, [NotNul
         /// <param name="force"> Don't check to see if the migration has been applied to the database. </param>
         /// <returns> The removed migration files. </returns>
         public virtual MigrationFiles RemoveMigration([NotNull] string projectDir, [NotNull] string rootNamespace, bool force)
-            => RemoveMigration(projectDir, rootNamespace, force, language: null);
+            => RemoveMigration(projectDir, rootNamespace, force, revert: false, language: null);
 
         /// <summary>
         ///     Removes the previous migration.
         /// </summary>
         /// <param name="projectDir"> The project's root directory. </param>
         /// <param name="rootNamespace"> The project's root namespace. </param>
         /// <param name="force"> Don't check to see if the migration has been applied to the database. </param>
+        /// <param name="revert"> Revert if the migration has been applied to the database before removing. </param>
         /// <param name="language"> The project's language. </param>
         /// <returns> The removed migration files. </returns>
         // TODO: DRY (file names)
         public virtual MigrationFiles RemoveMigration(
             [NotNull] string projectDir,
             [NotNull] string rootNamespace,
             bool force,
+            bool revert,
             [CanBeNull] string language)
         {
             Check.NotEmpty(projectDir, nameof(projectDir));
@@ -254,7 +256,18 @@ public virtual MigrationFiles RemoveMigration(
                     else if (Dependencies.HistoryRepository.GetAppliedMigrations().Any(
                         e => e.MigrationId.Equals(migration.GetId(), StringComparison.OrdinalIgnoreCase)))
                     {
-                        throw new OperationException(DesignStrings.RevertMigration(migration.GetId()));
+                        if (revert)
+                        {
+                            Dependencies.OperationReporter.WriteInformation(DesignStrings.RevertingMigration(migration.GetId()));
+                            Dependencies.Migrator.Migrate(
+                                migrations.Count > 1
+                                    ? migrations[migrations.Count - 2].GetId()
+                                    : Migration.InitialDatabase);
+                        }
+                        else
+                        {
+                            throw new OperationException(DesignStrings.RevertMigration(migration.GetId()));
+                        }
                     }
 
                     var migrationFileName = migration.GetId() + codeGenerator.FileExtension;

src/EFCore.Design/Migrations/Design/MigrationsScaffolderDependencies.cs

@@ -58,6 +58,7 @@ public sealed class MigrationsScaffolderDependencies
         /// <param name="operationReporter"> The operation reporter. </param>
         /// <param name="databaseProvider"> The database provider. </param>
         /// <param name="snapshotModelProcessor"> The snapshot model processor. </param>
+        /// <param name="migrator"> The migrator. </param>
         public MigrationsScaffolderDependencies(
             [NotNull] ICurrentDbContext currentDbContext,
             [NotNull] IModel model,
@@ -68,7 +69,8 @@ public MigrationsScaffolderDependencies(
             [NotNull] IHistoryRepository historyRepository,
             [NotNull] IOperationReporter operationReporter,
             [NotNull] IDatabaseProvider databaseProvider,
-            [NotNull] ISnapshotModelProcessor snapshotModelProcessor)
+            [NotNull] ISnapshotModelProcessor snapshotModelProcessor,
+            [NotNull] IMigrator migrator)
         {
             Check.NotNull(currentDbContext, nameof(currentDbContext));
             Check.NotNull(model, nameof(model));
@@ -80,6 +82,7 @@ public MigrationsScaffolderDependencies(
             Check.NotNull(operationReporter, nameof(operationReporter));
             Check.NotNull(databaseProvider, nameof(databaseProvider));
             Check.NotNull(snapshotModelProcessor, nameof(snapshotModelProcessor));
+            Check.NotNull(migrator, nameof(migrator));
 
             CurrentDbContext = currentDbContext;
             Model = model;
@@ -91,6 +94,7 @@ public MigrationsScaffolderDependencies(
             OperationReporter = operationReporter;
             DatabaseProvider = databaseProvider;
             SnapshotModelProcessor = snapshotModelProcessor;
+            Migrator = migrator;
         }
 
         /// <summary>
@@ -150,6 +154,11 @@ public IMigrationsCodeGenerator MigrationCodeGenerator
         /// </summary>
         public ISnapshotModelProcessor SnapshotModelProcessor { get; }
 
+        /// <summary>
+        ///     The migrator.
+        /// </summary>
+        public IMigrator Migrator { get; }
+
         /// <summary>
         ///     Clones this dependency parameter object with one service replaced.
         /// </summary>
@@ -166,7 +175,8 @@ public MigrationsScaffolderDependencies With([NotNull] ICurrentDbContext current
                 HistoryRepository,
                 OperationReporter,
                 DatabaseProvider,
-                SnapshotModelProcessor);
+                SnapshotModelProcessor,
+                Migrator);
 
         /// <summary>
         ///     Clones this dependency parameter object with one service replaced.
@@ -184,7 +194,8 @@ public MigrationsScaffolderDependencies With([NotNull] IModel model)
                 HistoryRepository,
                 OperationReporter,
                 DatabaseProvider,
-                SnapshotModelProcessor);
+                SnapshotModelProcessor,
+                Migrator);
 
         /// <summary>
         ///     Clones this dependency parameter object with one service replaced.
@@ -202,7 +213,8 @@ public MigrationsScaffolderDependencies With([NotNull] IMigrationsAssembly migra
                 HistoryRepository,
                 OperationReporter,
                 DatabaseProvider,
-                SnapshotModelProcessor);
+                SnapshotModelProcessor,
+                Migrator);
 
         /// <summary>
         ///     Clones this dependency parameter object with one service replaced.
@@ -220,7 +232,8 @@ public MigrationsScaffolderDependencies With([NotNull] IMigrationsModelDiffer mi
                 HistoryRepository,
                 OperationReporter,
                 DatabaseProvider,
-                SnapshotModelProcessor);
+                SnapshotModelProcessor,
+                Migrator);
 
         /// <summary>
         ///     Clones this dependency parameter object with one service replaced.
@@ -238,7 +251,8 @@ public MigrationsScaffolderDependencies With([NotNull] IMigrationsIdGenerator mi
                 HistoryRepository,
                 OperationReporter,
                 DatabaseProvider,
-                SnapshotModelProcessor);
+                SnapshotModelProcessor,
+                Migrator);
 
         /// <summary>
         ///     Clones this dependency parameter object with one service replaced.
@@ -269,7 +283,8 @@ public MigrationsScaffolderDependencies With([NotNull] MigrationsCodeGeneratorSe
                 HistoryRepository,
                 OperationReporter,
                 DatabaseProvider,
-                SnapshotModelProcessor);
+                SnapshotModelProcessor,
+                Migrator);
 
         /// <summary>
         ///     Clones this dependency parameter object with one service replaced.
@@ -287,7 +302,8 @@ public MigrationsScaffolderDependencies With([NotNull] IHistoryRepository histor
                 historyRepository,
                 OperationReporter,
                 DatabaseProvider,
-                SnapshotModelProcessor);
+                SnapshotModelProcessor,
+                Migrator);
 
         /// <summary>
         ///     Clones this dependency parameter object with one service replaced.
@@ -305,7 +321,8 @@ public MigrationsScaffolderDependencies With([NotNull] IOperationReporter operat
                 HistoryRepository,
                 operationReporter,
                 DatabaseProvider,
-                SnapshotModelProcessor);
+                SnapshotModelProcessor,
+                Migrator);
 
         /// <summary>
         ///     Clones this dependency parameter object with one service replaced.
@@ -323,7 +340,8 @@ public MigrationsScaffolderDependencies With([NotNull] IDatabaseProvider databas
                 HistoryRepository,
                 OperationReporter,
                 databaseProvider,
-                SnapshotModelProcessor);
+                SnapshotModelProcessor,
+                Migrator);
 
         /// <summary>
         ///     Clones this dependency parameter object with one service replaced.
@@ -341,6 +359,26 @@ public MigrationsScaffolderDependencies With([NotNull] ISnapshotModelProcessor s
                 HistoryRepository,
                 OperationReporter,
                 DatabaseProvider,
-                snapshotModelProcessor);
+                snapshotModelProcessor,
+                Migrator);
+
+        /// <summary>
+        ///     Clones this dependency parameter object with one service replaced.
+        /// </summary>
+        /// <param name="migrator"> A replacement for the current dependency of this type. </param>
+        /// <returns> A new parameter object with the given service replaced. </returns>
+        public MigrationsScaffolderDependencies With([NotNull] IMigrator migrator)
+            => new MigrationsScaffolderDependencies(
+                CurrentDbContext,
+                Model,
+                MigrationsAssembly,
+                MigrationsModelDiffer,
+                MigrationsIdGenerator,
+                MigrationCodeGeneratorSelector,
+                HistoryRepository,
+                OperationReporter,
+                DatabaseProvider,
+                SnapshotModelProcessor,
+                migrator);
     }
 }

src/EFCore.Design/Properties/DesignStrings.resx

@@ -342,4 +342,7 @@ Change your target project to the migrations project by using the Package Manage
   <data name="NoLanguageService" xml:space="preserve">
     <value>The project language '{language}' isn't supported by the built-in {service} service. You can try looking for an additional NuGet package which supports this language; moving your DbContext type to a C# class library referenced by this project; or manually implementing and registering the design-time service for programming language.</value>
   </data>
+  <data name="RevertingMigration" xml:space="preserve">
+    <value>Reverting migration '{name}'.</value>
+  </data>
 </root>

src/EFCore.Tools/tools/EntityFrameworkCore.psm1

@@ -199,6 +199,9 @@ Register-TabExpansion Remove-Migration @{
 .PARAMETER Force
     Don't check to see if the migration has been applied to the database. Always implied on UWP apps.
 
+.PARAMETER Revert
+    Revert the migration if it has been applied to the database.
+
 .PARAMETER Context
     The DbContext to use.
 
@@ -215,7 +218,7 @@ Register-TabExpansion Remove-Migration @{
 function Remove-Migration
 {
     [CmdletBinding(PositionalBinding = $false)]
-    param([switch] $Force, [string] $Context, [string] $Project, [string] $StartupProject)
+    param([switch] $Force, [switch] $Revert, [string] $Context, [string] $Project, [string] $StartupProject)
 
     $dteProject = GetProject $Project
     $dteStartupProject = GetStartupProject $StartupProject $dteProject
@@ -227,6 +230,11 @@ function Remove-Migration
         $params += '--force'
     }
 
+    if ($Revert)
+    {
+        $params += '--revert'
+    }
+
     $params += GetParams $Context
 
     # NB: -join is here to support ConvertFrom-Json on PowerShell 3.0

src/dotnet-ef/Properties/Resources.Designer.tt

@@ -1,5 +1,6 @@
 <#
     Session["ResourceFile"] = "Resources.resx";
     Session["AccessModifier"] = "internal";
+    Session["NoDiagnostics"] = true;
 #>
 <#@ include file="..\..\..\tools\Resources.tt" #>