Merge pull request #30 from koenbeuk/issue/capture-unmodified

Issue capture unmodified

Author: koenbeuk

src/EntityFrameworkCore.Triggered/TriggerContext.cs

@@ -12,31 +12,23 @@ public class TriggerContext<TEntity> : ITriggerContext<TEntity>
         where TEntity: class
     {
         readonly ChangeType _type;
-        readonly EntityEntry _entityEntry;
-        readonly Lazy<TEntity?> _unmodifiedEntityLazy;
-
-        TEntity? CreateUnmodified()
-        {
-            if (ChangeType == ChangeType.Added)
-            {
-                return null;
-            }
-            else
-            {
-                return (TEntity)_entityEntry.OriginalValues.ToObject();
-            }
-        }
+        readonly TEntity _entity;
+        readonly TEntity? _unmodifiedEntity;
 
 
         public TriggerContext(EntityEntry entityEntry, ChangeType changeType)
         {
             _type = changeType;
-            _entityEntry = entityEntry;
-            _unmodifiedEntityLazy = new Lazy<TEntity?>(CreateUnmodified, false);
+            _entity = (TEntity)entityEntry.Entity;
+            
+            if (changeType != ChangeType.Added)
+            {
+                _unmodifiedEntity = (TEntity)entityEntry.OriginalValues.ToObject();
+            }
         }
 
         public ChangeType ChangeType => _type;
-        public TEntity Entity => (TEntity)_entityEntry.Entity;
-        public TEntity? UnmodifiedEntity => _unmodifiedEntityLazy.Value;
+        public TEntity Entity => _entity;
+        public TEntity? UnmodifiedEntity => _unmodifiedEntity;
     }
 }

test/EntityFrameworkCore.Triggered.Tests/Internal/TriggerContextFactoryTests.cs

@@ -4,19 +4,40 @@
 using System.Text;
 using System.Threading.Tasks;
 using EntityFrameworkCore.Triggered.Internal;
+using Microsoft.EntityFrameworkCore;
 using Xunit;
 
 namespace EntityFrameworkCore.Triggered.Tests.Internal
 {
     public class TriggerContextFactoryTests
     {
+        class TestModel
+        {
+            public Guid Id { get; set; }
+            public string Name { get; set; }
+        }
+
+        class TestDbContext : DbContext
+        {
+            public DbSet<TestModel> TestModels { get; set; }
+
+            protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+            {
+                base.OnConfiguring(optionsBuilder);
+
+                optionsBuilder.UseInMemoryDatabase(nameof(TriggerContextFactoryTests));
+            }
+        }
+
         [Fact]
         public void Activate_ReturnsInstance()
         {
-            var result = TriggerContextFactory<object>.Activate(null, ChangeType.Added);
+            using var dbContext = new TestDbContext();
+            var entityEntry = dbContext.Entry(new TestModel { });
+
+            var result = TriggerContextFactory<object>.Activate(entityEntry, ChangeType.Added);
 
             Assert.NotNull(result);
         }
-
     }
 }

test/EntityFrameworkCore.Triggered.Tests/TriggerContextTests.cs

@@ -11,7 +11,7 @@ namespace EntityFrameworkCore.Triggered.Tests.Internal
 {
     public class TriggerContextTests
     {
-        class TestModel { public int Id { get; set; } }
+        class TestModel { public int Id { get; set; } public string Name { get; set; } }
 
         class TestDbContext : DbContext
         {
@@ -53,6 +53,40 @@ public void UnmodifiedEntity_WhenTypeModified_IsNotEmpty()
             Assert.NotNull(subject.UnmodifiedEntity);
         }
 
+        [Fact]
+        public void UnmodifiedEntity_WhenTypeModified_HoldsUnmodifiedStateBeforeSaveChanges()
+        {
+            using var dbContext = new TestDbContext();
+            var sample1 = new TestModel { Name = "test1" };
+            dbContext.Add(sample1);
+            dbContext.SaveChanges();
+
+            var subject = new TriggerContext<TestModel>(dbContext.Entry(sample1), ChangeType.Modified);
+            sample1.Name = "test2";
+
+            Assert.NotNull(subject.UnmodifiedEntity);
+            Assert.Equal("test1", subject.UnmodifiedEntity.Name);
+
+            dbContext.SaveChanges();
+        }
+
+        [Fact]
+        public void UnmodifiedEntity_WhenTypeModified_HoldsUnmodifiedStateAfterSaveChanges()
+        {
+            using var dbContext = new TestDbContext();
+            var sample1 = new TestModel { Name = "test1" };
+            dbContext.Add(sample1);
+            dbContext.SaveChanges();
+
+            var subject = new TriggerContext<TestModel>(dbContext.Entry(sample1), ChangeType.Modified);
+            sample1.Name = "test2";
+
+            dbContext.SaveChanges();
+             
+            Assert.NotNull(subject.UnmodifiedEntity);
+            Assert.Equal("test1", subject.UnmodifiedEntity.Name);
+        }
+
         [Fact]
         public void Entity_IsNeverEmpty()
         {