Add & fire events before & after a successful migration

src/Evolve/Configuration/IEvolveConfiguration.cs

@@ -1,6 +1,8 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Reflection;
 using System.Text;
+using EvolveDb.Events;
 using EvolveDb.Migration;
 
 namespace EvolveDb.Configuration
@@ -218,5 +220,15 @@ public interface IEvolveConfiguration
         ///     that replaces the built-in ones (<see cref="FileMigrationLoader"/> <see cref="EmbeddedResourceMigrationLoader"/>)
         /// </summary>
         IMigrationLoader MigrationLoader { get; }
+
+        /// <summary>
+        ///  Event raised when Evolve is about to execute a migration script.
+        /// </summary>
+        event EventHandler<MigrationEventArgs> MigrationStarting;
+
+        /// <summary>
+        /// Event raised when Evolve has successfully executed a migration script.
+        /// </summary>
+        event EventHandler<MigrationEventArgs> MigrationSucceeded;
     }
 }

src/Evolve/Events/MigrationEventArgs.cs

@@ -0,0 +1,15 @@
+using System;
+using EvolveDb.Migration;
+
+namespace EvolveDb.Events;
+
+public sealed class MigrationEventArgs : EventArgs
+{
+    public MigrationScript? Migration { get; }
+
+
+    public MigrationEventArgs(MigrationScript migration)
+    {
+        Migration = migration;
+    }
+}

src/Evolve/Evolve.cs

@@ -12,6 +12,7 @@
 using EvolveDb.Configuration;
 using EvolveDb.Connection;
 using EvolveDb.Dialect;
+using EvolveDb.Events;
 using EvolveDb.Metadata;
 using EvolveDb.Migration;
 using EvolveDb.Utilities;
@@ -89,6 +90,10 @@ public IMigrationLoader MigrationLoader
             }
             set { _migrationLoader = value; }
         }
+
+        public event EventHandler<MigrationEventArgs>? MigrationStarting;
+
+        public event EventHandler<MigrationEventArgs>? MigrationSucceeded;
 
         #endregion
 
@@ -453,6 +458,7 @@ private void InternalMigrate(DatabaseHelper db)
 
             MigrationVersion Migrate()
             {
+
                 ExecuteAllOutOfOrderMigration(db);
                 var lastAppliedVersion = ExecuteAllMigration(db);
                 ExecuteAllRepeatableMigration(db);
@@ -790,6 +796,7 @@ private void ExecuteMigration(MigrationScript migration, DatabaseHelper db)
 
             try
             {
+                MigrationStarting?.Invoke(this, new MigrationEventArgs(migration));
                 stopWatch.Start();
                 foreach (var statement in db.SqlStatementBuilder.LoadSqlStatements(migration, Placeholders))
                 {
@@ -813,6 +820,7 @@ private void ExecuteMigration(MigrationScript migration, DatabaseHelper db)
                 TotalTimeElapsedInMs += stopWatch.ElapsedMilliseconds;
                 NbMigration++;
                 AppliedMigrations.Add(migration.Name);
+                MigrationSucceeded?.Invoke(this, new MigrationEventArgs(migration));
             }
             catch (Exception ex)
             {

test/Evolve.Tests/AssertHelper.cs

@@ -217,13 +217,19 @@ public static Evolve AssertMigrateIsSuccessful(this Evolve evolve, IDbConnection
             cnn.TryClose();
             arrange?.Invoke(evolve);
             int expectedNbMigration = evolve.GetExpectedNbMigration();
+            MigrationScript migrationStarting = null;
+            MigrationScript migrationSucceeded = null;
+            evolve.MigrationStarting += (_, args) => migrationStarting = args.Migration;
+            evolve.MigrationSucceeded += (_, args) => migrationSucceeded = args.Migration;
 
             // Act
             evolve.Migrate();
             // Assert
             Assert.True(evolve.NbMigration == expectedNbMigration, $"{expectedNbMigration} migrations should have been applied, not {evolve.NbMigration}.");
             Assert.True(evolve.AppliedMigrations.Count == expectedNbMigration);
             Assert.True(cnn.State == ConnectionState.Closed);
+            Assert.NotNull(migrationStarting);
+            Assert.NotNull(migrationSucceeded);
 
             // Act
             evolve.Migrate();

test/Evolve.Tests/EvolveConfiguration.cs

@@ -1,8 +1,10 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using System.Text;
 using EvolveDb.Configuration;
+using EvolveDb.Events;
 using EvolveDb.Migration;
 
 namespace EvolveDb.Tests
@@ -53,5 +55,8 @@ public IMigrationLoader MigrationLoader
             }
             set { _migrationLoader = value; }
         }
+
+        public event EventHandler<MigrationEventArgs> MigrationStarting;
+        public event EventHandler<MigrationEventArgs> MigrationSucceeded;
     }
 }