Improve UOW event order and add tests

framework/src/Volo.Abp.Uow/Volo/Abp/Uow/ChildUnitOfWork.cs

@@ -15,6 +15,10 @@ namespace Volo.Abp.Uow
 
         public bool IsReserved => _parent.IsReserved;
 
+        public bool IsDisposed => _parent.IsDisposed;
+
+        public bool IsCompleted => _parent.IsCompleted;
+
         public string ReservationName => _parent.ReservationName;
 
         public event EventHandler<UnitOfWorkFailedEventArgs> Failed;

framework/src/Volo.Abp.Uow/Volo/Abp/Uow/IUnitOfWork.cs

@@ -20,6 +20,10 @@ namespace Volo.Abp.Uow
 
         bool IsReserved { get; }
 
+        bool IsDisposed { get; }
+
+        bool IsCompleted { get; }
+
         string ReservationName { get; }
 
         void SetOuter([CanBeNull] IUnitOfWork outer);

framework/src/Volo.Abp.Uow/Volo/Abp/Uow/UnitOfWork.cs

@@ -18,6 +18,10 @@ namespace Volo.Abp.Uow
 
         public bool IsReserved { get; set; }
 
+        public bool IsDisposed { get; private set; }
+
+        public bool IsCompleted { get; private set; }
+
         public string ReservationName { get; set; }
 
         protected List<Func<Task>> CompletedHandlers { get; } = new List<Func<Task>>();
@@ -32,8 +36,7 @@ namespace Volo.Abp.Uow
         private readonly UnitOfWorkDefaultOptions _defaultOptions;
 
         private Exception _exception;
-        private bool _isCompleted;
-        private bool _isDisposed;
+        private bool _isCompleting;
         private bool _isRolledback;
 
         public UnitOfWork(IServiceProvider serviceProvider, IOptions<UnitOfWorkDefaultOptions> options)
@@ -101,8 +104,10 @@ namespace Volo.Abp.Uow
 
             try
             {
+                _isCompleting = true;
                 SaveChanges();
                 CommitTransactions();
+                IsCompleted = true;
                 OnCompleted();
             }
             catch (Exception ex)
@@ -123,8 +128,10 @@ namespace Volo.Abp.Uow
 
             try
             {
+                _isCompleting = true;
                 await SaveChangesAsync(cancellationToken);
                 await CommitTransactionsAsync();
+                IsCompleted = true;
                 await OnCompletedAsync();
             }
             catch (Exception ex)
@@ -250,16 +257,16 @@ namespace Volo.Abp.Uow
 
         public virtual void Dispose()
         {
-            if (_isDisposed)
+            if (IsDisposed)
             {
                 return;
             }
 
-            _isDisposed = true;
+            IsDisposed = true;
 
             DisposeTransactions();
 
-            if (!_isCompleted || _exception != null)
+            if (!IsCompleted || _exception != null)
             {
                 OnFailed();
             }
@@ -283,15 +290,12 @@ namespace Volo.Abp.Uow
 
         private void PreventMultipleComplete()
         {
-            if (_isCompleted)
+            if (IsCompleted || _isCompleting)
             {
                 throw new AbpException("Complete is called before!");
             }
-
-            _isCompleted = true;
         }
 
-
         protected virtual void RollbackAll()
         {
             foreach (var databaseApi in _databaseApis.Values)

framework/src/Volo.Abp.Uow/Volo/Abp/Uow/UnitOfWorkManager.cs

@@ -23,9 +23,10 @@ namespace Volo.Abp.Uow
         {
             Check.NotNull(options, nameof(options));
 
-            if (!requiresNew && _ambientUnitOfWork.UnitOfWork != null && !_ambientUnitOfWork.UnitOfWork.IsReserved)
+            var currentUow = Current;
+            if (currentUow != null && !requiresNew)
             {
-                return new ChildUnitOfWork(_ambientUnitOfWork.UnitOfWork);
+                return new ChildUnitOfWork(currentUow);
             }
 
             var unitOfWork = CreateNewUnitOfWork();
@@ -86,7 +87,7 @@ namespace Volo.Abp.Uow
             var uow = _ambientUnitOfWork.UnitOfWork;
 
             //Skip reserved unit of work
-            while (uow != null && uow.IsReserved)
+            while (uow != null && (uow.IsReserved || uow.IsDisposed || uow.IsCompleted))
             {
                 uow = uow.Outer;
             }

framework/test/Volo.Abp.EntityFrameworkCore.Tests/Volo/Abp/EntityFrameworkCore/EntityFrameworkCoreTestBase.cs

@@ -1,9 +1,4 @@
-using System;
-using System.Threading.Tasks;
-using Microsoft.Extensions.DependencyInjection;
-using Volo.Abp.Uow;
-
-namespace Volo.Abp.EntityFrameworkCore
+namespace Volo.Abp.EntityFrameworkCore
 {
     public abstract class EntityFrameworkCoreTestBase : AbpIntegratedTest<AbpEntityFrameworkCoreTestModule>
     {

framework/test/Volo.Abp.EntityFrameworkCore.Tests/Volo/Abp/EntityFrameworkCore/Uow/Uow_Completed_Tests.cs

@@ -0,0 +1,9 @@
+using Volo.Abp.TestApp.Testing;
+
+namespace Volo.Abp.EntityFrameworkCore.Uow
+{
+    public class Uow_Completed_Tests : Uow_Completed_Tests<AbpEntityFrameworkCoreTestModule>
+    {
+
+    }
+}

framework/test/Volo.Abp.MongoDB.Tests/Volo/Abp/MongoDB/Uow/Uow_Completed_Tests.cs

@@ -0,0 +1,9 @@
+using Volo.Abp.TestApp.Testing;
+
+namespace Volo.Abp.MongoDB.Uow
+{
+    public class Uow_Completed_Tests : Uow_Completed_Tests<AbpMongoDbTestModule>
+    {
+
+    }
+}

framework/test/Volo.Abp.TestApp/Volo/Abp/TestApp/Testing/Uow_Completed_Tests.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Threading.Tasks;
+using Volo.Abp.Modularity;
+using Volo.Abp.TestApp.Domain;
+using Volo.Abp.Uow;
+using Xunit;
+
+namespace Volo.Abp.TestApp.Testing
+{
+    public abstract class Uow_Completed_Tests<TStartupModule> : TestAppTestBase<TStartupModule>
+        where TStartupModule : IAbpModule
+    {
+        private readonly IUnitOfWorkManager _unitOfWorkManager;
+        private readonly ICityRepository _cityRepository;
+
+        protected Uow_Completed_Tests()
+        {
+            _unitOfWorkManager = GetRequiredService<IUnitOfWorkManager>();
+            _cityRepository = GetRequiredService<ICityRepository>();
+        }
+
+        [Fact]
+        public async Task Should_Be_Able_To_Perform_Database_Operation_On_Uow_Complete()
+        {
+            using (var uow = _unitOfWorkManager.Begin())
+            {
+                //Perform an arbitrary database operation
+                await _cityRepository.InsertAsync(new City(Guid.NewGuid(), Guid.NewGuid().ToString()));
+
+                uow.OnCompleted(async () =>
+                {
+                    //Perform another database operation inside the OnCompleted handler
+                    await _cityRepository.InsertAsync(new City(Guid.NewGuid(), Guid.NewGuid().ToString()));
+                });
+
+                await uow.CompleteAsync();
+            }
+        }
+    }
+}