Keep the ambient cancellation token out of the entity paths

* Only the projected GetAsync passes it, that is the path Repository.GetAsync already covered
* Assert a single data query so a materialize-then-project implementation can not pass
* Opting out of the projection brings the entity based overrides back

framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/AbstractKeyReadOnlyAppService.cs

@@ -92,7 +92,7 @@ public abstract class AbstractKeyReadOnlyAppService<TEntity, TGetOutputDto, TGet
         await CheckGetListPolicyAsync();
 
         var query = await CreateFilteredQueryAsync(input);
-        var totalCount = await AsyncExecuter.CountAsync(query, GetCancellationToken());
+        var totalCount = await AsyncExecuter.CountAsync(query);
 
         var entityDtos = new List<TGetListOutputDto>();
 
@@ -104,11 +104,11 @@ public abstract class AbstractKeyReadOnlyAppService<TEntity, TGetOutputDto, TGet
             var dtoQuery = await CreateGetListOutputDtoQueryOrNullAsync(query);
             if (dtoQuery != null)
             {
-                entityDtos = await AsyncExecuter.ToListAsync(dtoQuery, GetCancellationToken());
+                entityDtos = await AsyncExecuter.ToListAsync(dtoQuery);
             }
             else
             {
-                var entities = await AsyncExecuter.ToListAsync(query, GetCancellationToken());
+                var entities = await AsyncExecuter.ToListAsync(query);
                 entityDtos = await MapToGetListOutputDtosAsync(entities);
             }
         }
@@ -121,9 +121,11 @@ public abstract class AbstractKeyReadOnlyAppService<TEntity, TGetOutputDto, TGet
 
     protected abstract Task<TEntity> GetEntityByIdAsync(TKey id);
 
-    protected virtual CancellationToken GetCancellationToken(CancellationToken preferredValue = default)
+    private CancellationToken GetCancellationToken()
     {
-        return CancellationTokenProvider.FallbackToProvider(preferredValue);
+        return LazyServiceProvider
+            .LazyGetService<ICancellationTokenProvider>(NullCancellationTokenProvider.Instance)
+            .FallbackToProvider();
     }
 
     /// <summary>

framework/src/Volo.Abp.Ddd.Application/Volo/Abp/Application/Services/ApplicationService.cs

@@ -19,7 +19,6 @@ using Volo.Abp.Localization;
 using Volo.Abp.MultiTenancy;
 using Volo.Abp.ObjectMapping;
 using Volo.Abp.Settings;
-using Volo.Abp.Threading;
 using Volo.Abp.Timing;
 using Volo.Abp.Uow;
 using Volo.Abp.Users;
@@ -49,8 +48,6 @@ public abstract class ApplicationService :
 
     protected IAsyncQueryableExecuter AsyncExecuter => LazyServiceProvider.LazyGetRequiredService<IAsyncQueryableExecuter>();
 
-    protected ICancellationTokenProvider CancellationTokenProvider => LazyServiceProvider.LazyGetService<ICancellationTokenProvider>(NullCancellationTokenProvider.Instance);
-
     protected Type? ObjectMapperContext { get; set; }
     protected IObjectMapper ObjectMapper => LazyServiceProvider.LazyGetService<IObjectMapper>(provider =>
         ObjectMapperContext == null

framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/AbpObjectMappingModule.cs

@@ -21,7 +21,6 @@ public class AbpObjectMappingModule : AbpModule
             );
 
             //Register types for IQueryProjector<TSource, TDestination> if implements
-            //The class name convention may have already exposed them, so they are not added twice
             foreach (var serviceType in ReflectionHelper.GetImplementedGenericTypes(
                          onServiceExposingContext.ImplementationType,
                          typeof(IQueryProjector<,>)))

framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/IQueryProjector.cs

@@ -7,7 +7,8 @@ namespace Volo.Abp.ObjectMapping;
 /// Maps a query to another.
 /// Implement this interface to project a query on the data store side, instead of loading the
 /// source objects into the memory and mapping them one by one.
-/// Implement it once for a source and destination pair, the last registered one is used otherwise.
+/// Implement it once for a source and destination pair. Use the ReplaceServices option of the
+/// DependencyAttribute to replace an existing implementation.
 /// </summary>
 /// <typeparam name="TSource">Type of the source objects</typeparam>
 /// <typeparam name="TDestination">Type of the destination objects</typeparam>

framework/test/Volo.Abp.Ddd.Application.Tests/Volo/Abp/Application/Services/QueryProjection/BookCustomizedAppService.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
 using Volo.Abp.Domain.Repositories;
 
@@ -25,4 +26,9 @@ public class BookCustomizedAppService : CrudAppService<Book, BookDto, Guid>
     {
         return Task.FromResult(new BookDto { Id = entity.Id, Name = entity.Name + Marker });
     }
+
+    protected override Task<List<BookDto>> MapToGetListOutputDtosAsync(List<Book> entities)
+    {
+        return Task.FromResult(entities.ConvertAll(entity => new BookDto { Id = entity.Id, Name = entity.Name + Marker }));
+    }
 }

framework/test/Volo.Abp.Ddd.Application.Tests/Volo/Abp/Application/Services/QueryProjection/BookWithoutProjectionAppService.cs

@@ -1,5 +1,7 @@
 #nullable enable
 using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
 using Volo.Abp.Domain.Repositories;
 using Volo.Abp.ObjectMapping;
 
@@ -7,6 +9,8 @@ namespace Volo.Abp.Application.Services.QueryProjection;
 
 public class BookWithoutProjectionAppService : CrudAppService<Book, BookDto, Guid>
 {
+    public const string Marker = "-not-projected";
+
     protected override IQueryProjector<Book, BookDto>? GetOutputDtoQueryProjector => null;
 
     protected override IQueryProjector<Book, BookDto>? GetListOutputDtoQueryProjector => null;
@@ -16,4 +20,14 @@ public class BookWithoutProjectionAppService : CrudAppService<Book, BookDto, Gui
     {
 
     }
+
+    protected override Task<BookDto> MapToGetOutputDtoAsync(Book entity)
+    {
+        return Task.FromResult(new BookDto { Id = entity.Id, Name = entity.Name + Marker });
+    }
+
+    protected override Task<List<BookDto>> MapToGetListOutputDtosAsync(List<Book> entities)
+    {
+        return Task.FromResult(entities.ConvertAll(entity => new BookDto { Id = entity.Id, Name = entity.Name + Marker }));
+    }
 }

framework/test/Volo.Abp.Ddd.Application.Tests/Volo/Abp/Application/Services/QueryProjection/QueryProjection_Tests.cs

@@ -66,13 +66,13 @@ public class QueryProjection_Tests : AbpDddApplicationTestBase
     }
 
     [Fact]
-    public async Task Should_Use_The_Object_Mapper_If_The_Projection_Was_Disabled()
+    public async Task Should_Use_The_Entity_Based_Overrides_If_The_Projection_Was_Disabled()
     {
         var appService = GetRequiredService<BookWithoutProjectionAppService>();
 
-        (await appService.GetAsync(_bookId)).Name.ShouldEndWith(BookObjectMapper.Marker);
+        (await appService.GetAsync(_bookId)).Name.ShouldEndWith(BookWithoutProjectionAppService.Marker);
         (await appService.GetListAsync(new PagedAndSortedResultRequestDto()))
-            .Items[0].Name.ShouldEndWith(BookObjectMapper.Marker);
+            .Items[0].Name.ShouldEndWith(BookWithoutProjectionAppService.Marker);
     }
 
     [Fact]
@@ -84,6 +84,11 @@ public class QueryProjection_Tests : AbpDddApplicationTestBase
 
         dto.Name.ShouldEndWith(BookProjector.Marker);
         dto.Name.ShouldNotContain(BookCustomizedAppService.Marker);
+
+        var items = (await appService.GetListAsync(new PagedAndSortedResultRequestDto())).Items;
+
+        items[0].Name.ShouldEndWith(BookProjector.Marker);
+        items[0].Name.ShouldNotContain(BookCustomizedAppService.Marker);
     }
 
     [Fact]

framework/test/Volo.Abp.EntityFrameworkCore.Tests/Volo/Abp/EntityFrameworkCore/Applications/PersonWithCityDto.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using System;
 using Volo.Abp.Application.Dtos;
 
@@ -7,5 +8,5 @@ public class PersonWithCityDto : EntityDto<Guid>
 {
     public string Name { get; set; }
 
-    public string CityName { get; set; }
+    public string? CityName { get; set; }
 }

framework/test/Volo.Abp.EntityFrameworkCore.Tests/Volo/Abp/EntityFrameworkCore/Applications/QueryProjection_Tests.cs

@@ -129,8 +129,9 @@ public class QueryProjection_Tests : EntityFrameworkCoreTestBase
         }
 
         //the application service must run the projection itself, not materialize the entities first
-        var select = commands.Last(x => x.Contains("FROM \"People\"") && !x.Contains("COUNT"));
+        var selects = commands.Where(x => x.Contains("FROM \"People\"") && !x.Contains("COUNT")).ToList();
 
+        var select = selects.ShouldHaveSingleItem();
         select.ShouldContain("\"Name\"");
         select.ShouldNotContain("\"Birthday\"");
         select.ShouldNotContain("\"ExtraProperties\"");
@@ -151,26 +152,46 @@ public class QueryProjection_Tests : EntityFrameworkCoreTestBase
         var cancellationTokenProvider = GetRequiredService<ICancellationTokenProvider>();
         var appService = GetRequiredService<PersonProjectionAppService>();
 
+        //the entity path passes it through Repository.GetAsync, so the projected path must not regress
         using (cancellationTokenProvider.Use(new CancellationToken(canceled: true)))
         {
             await Should.ThrowAsync<OperationCanceledException>(async () =>
                 await appService.GetAsync(TestDataBuilder.UserDouglasId));
+        }
+    }
 
-            await Should.ThrowAsync<OperationCanceledException>(async () =>
-                await appService.GetListAsync(new PagedAndSortedResultRequestDto()));
+    [Fact]
+    public async Task Should_Execute_The_Projected_Query_From_The_Application_Service_For_A_Single_Entity()
+    {
+        System.Collections.Concurrent.ConcurrentQueue<string> commands;
+        using (SqlCommandCapture.Begin(out commands))
+        {
+            await GetRequiredService<PersonProjectionAppService>().GetAsync(TestDataBuilder.UserDouglasId);
         }
+
+        var selects = commands.Where(x => x.Contains("FROM \"People\"")).ToList();
+
+        var select = selects.ShouldHaveSingleItem();
+        select.ShouldContain("\"Name\"");
+        select.ShouldNotContain("\"Birthday\"");
+        select.ShouldNotContain("\"ExtraProperties\"");
     }
 
     [Fact]
-    public async Task Should_Use_The_Ambient_Cancellation_Token_Without_A_Projector()
+    public async Task Should_Apply_The_Data_Filters_Of_The_Joined_Aggregate()
     {
-        var cancellationTokenProvider = GetRequiredService<ICancellationTokenProvider>();
-        var appService = GetRequiredService<IPeopleAppService>();
+        var cityRepository = GetRequiredService<IRepository<City, Guid>>();
 
-        using (cancellationTokenProvider.Use(new CancellationToken(canceled: true)))
+        await WithUnitOfWorkAsync(async () =>
         {
-            await Should.ThrowAsync<OperationCanceledException>(async () =>
-                await appService.GetListAsync(new PagedAndSortedResultRequestDto()));
-        }
+            var london = await cityRepository.GetAsync(TestDataBuilder.LondonCityId);
+            await cityRepository.DeleteAsync(london, autoSave: true);
+        });
+
+        var result = await GetRequiredService<PersonWithCityAppService>()
+            .GetListAsync(new PagedAndSortedResultRequestDto());
+
+        //the soft deleted city is filtered out, the left join still keeps the person
+        result.Items.ShouldContain(x => x.Name == "Douglas" && x.CityName == null);
     }
 }