Cosmos: Projection binding initialize empty collections

src/EFCore.Cosmos/Query/Internal/CosmosShapedQueryCompilingExpressionVisitor.CosmosProjectionBindingRemovingExpressionVisitorBase.cs

@@ -37,10 +37,6 @@ private static readonly MethodInfo CollectionAccessorAddMethodInfo
             = typeof(IClrCollectionAccessor).GetTypeInfo()
                 .GetDeclaredMethod(nameof(IClrCollectionAccessor.Add));
 
-        private static readonly MethodInfo CollectionAccessorGetOrCreateMethodInfo
-            = typeof(IClrCollectionAccessor).GetTypeInfo()
-                .GetDeclaredMethod(nameof(IClrCollectionAccessor.GetOrCreate));
-
         private readonly IDictionary<ParameterExpression, Expression> _materializationContextBindings
             = new Dictionary<ParameterExpression, Expression>();
 
@@ -402,7 +398,6 @@ private void AddInclude(
             var inverseNavigation = navigation.Inverse;
             var fixup = GenerateFixup(
                 includingClrType, relatedEntityClrType, navigation, inverseNavigation);
-            var initialize = GenerateInitialize(includingClrType, navigation);
 
             var navigationExpression = Visit(includeExpression.NavigationExpression);
 
@@ -421,7 +416,6 @@ private void AddInclude(
                         Constant(navigation),
                         Constant(inverseNavigation, typeof(INavigation)),
                         Constant(fixup),
-                        Constant(initialize, typeof(Action<>).MakeGenericType(includingClrType)),
 #pragma warning disable EF1001 // Internal EF Core API usage.
                         Constant(includeExpression.SetLoaded))));
 #pragma warning restore EF1001 // Internal EF Core API usage.
@@ -441,8 +435,7 @@ private static void IncludeReference<TIncludingEntity, TIncludedEntity>(
             INavigation navigation,
             INavigation inverseNavigation,
             Action<TIncludingEntity, TIncludedEntity> fixup,
-            Action<TIncludingEntity> _,
-            bool __)
+            bool _)
         {
             if (entity == null
                 || !navigation.DeclaringEntityType.IsAssignableFrom(entityType))
@@ -486,7 +479,6 @@ private static void IncludeCollection<TIncludingEntity, TIncludedEntity>(
             INavigation navigation,
             INavigation inverseNavigation,
             Action<TIncludingEntity, TIncludedEntity> fixup,
-            Action<TIncludingEntity> initialize,
             bool setLoaded)
         {
             if (entity == null
@@ -495,6 +487,8 @@ private static void IncludeCollection<TIncludingEntity, TIncludedEntity>(
                 return;
             }
 
+            navigation.GetCollectionAccessor()!.GetOrCreate(entity, forMaterialization: true);
+
             if (entry == null)
             {
                 var includingEntity = (TIncludingEntity)entity;
@@ -508,10 +502,6 @@ private static void IncludeCollection<TIncludingEntity, TIncludedEntity>(
                         inverseNavigation?.SetIsLoadedWhenNoTracking(relatedEntity);
                     }
                 }
-                else
-                {
-                    initialize(includingEntity);
-                }
             }
             else
             {
@@ -524,15 +514,12 @@ private static void IncludeCollection<TIncludingEntity, TIncludedEntity>(
 
                 if (relatedEntities != null)
                 {
+                    // Enumerator contains logic for tracking the entities, so we need to make sure to enumerate it
                     using var enumerator = relatedEntities.GetEnumerator();
                     while (enumerator.MoveNext())
                     {
                     }
                 }
-                else
-                {
-                    initialize((TIncludingEntity)entity);
-                }
             }
         }
 
@@ -563,27 +550,6 @@ private static Delegate GenerateFixup(
                 .Compile();
         }
 
-        private static Delegate GenerateInitialize(
-            Type entityType,
-            INavigation navigation)
-        {
-            if (!navigation.IsCollection)
-            {
-                return null;
-            }
-
-            var entityParameter = Parameter(entityType);
-
-            var getOrCreateExpression = Call(
-                Constant(navigation.GetCollectionAccessor()),
-                CollectionAccessorGetOrCreateMethodInfo,
-                entityParameter,
-                Constant(true));
-
-            return Lambda(Block(typeof(void), getOrCreateExpression), entityParameter)
-                .Compile();
-        }
-
         private static Expression AssignReferenceNavigation(
             ParameterExpression entity,
             ParameterExpression relatedEntity,

test/EFCore.Cosmos.FunctionalTests/Query/Associations/OwnedNavigations/OwnedNavigationsCosmosFixture.cs

@@ -31,82 +31,4 @@ protected override void OnModelCreating(ModelBuilder modelBuilder, DbContext con
             .ToContainer("RootEntities")
             .HasNoDiscriminator();
     }
-
-    // We need to override the following asserters because of #36577:
-    // the Cosmos provider incorrectly returns null for empty collections in some cases
-    protected override void AssertRootEntity(RootEntity e, RootEntity a)
-    {
-        Assert.Equal(e.Id, a.Id);
-        Assert.Equal(e.Name, a.Name);
-
-        NullSafeAssert<AssociateType>(e.RequiredAssociate, a.RequiredAssociate, AssertAssociate);
-        NullSafeAssert<AssociateType>(e.OptionalAssociate, a.OptionalAssociate, AssertAssociate);
-
-        if (e.AssociateCollection is not null && a.AssociateCollection is not null)
-        {
-            Assert.Equal(e.AssociateCollection.Count, a.AssociateCollection.Count);
-
-            var (orderedExpected, orderedActual) = (e.AssociateCollection, a.AssociateCollection);
-
-            for (var i = 0; i < e.AssociateCollection.Count; i++)
-            {
-                AssertAssociate(orderedExpected[i], orderedActual[i]);
-            }
-        }
-        else
-        {
-            // #36577: the Cosmos provider incorrectly returns null for empty collections in some cases
-            if (e.AssociateCollection is [] && a.AssociateCollection is null)
-            {
-                return;
-            }
-
-            Assert.Equal(e.AssociateCollection, a.AssociateCollection);
-        }
-    }
-
-    protected override void AssertAssociate(AssociateType e, AssociateType a)
-    {
-        Assert.Equal(e.Id, a.Id);
-        Assert.Equal(e.Name, a.Name);
-
-        Assert.Equal(e.Int, a.Int);
-        Assert.Equal(e.String, a.String);
-
-        NullSafeAssert<NestedAssociateType>(e.RequiredNestedAssociate, a.RequiredNestedAssociate, AssertNestedAssociate);
-        NullSafeAssert<NestedAssociateType>(e.OptionalNestedAssociate, a.OptionalNestedAssociate, AssertNestedAssociate);
-
-        if (e.NestedCollection is not null && a.NestedCollection != null)
-        {
-            Assert.Equal(e.NestedCollection.Count, a.NestedCollection.Count);
-
-            var (orderedExpected, orderedActual) = (e.NestedCollection, a.NestedCollection);
-
-            for (var i = 0; i < e.NestedCollection.Count; i++)
-            {
-                AssertNestedAssociate(orderedExpected[i], orderedActual[i]);
-            }
-        }
-        else
-        {
-            // #36577: the Cosmos provider incorrectly returns null for empty collections in some cases
-            if (e.NestedCollection is [] && a.NestedCollection is null)
-            {
-                return;
-            }
-
-            Assert.Equal(e.NestedCollection, a.NestedCollection);
-        }
-    }
-
-    private static void NullSafeAssert<T>(object? e, object? a, Action<T, T> assertAction)
-    {
-        if (e is T ee && a is T aa)
-        {
-            assertAction(ee, aa);
-            return;
-        }
-
-        Assert.Equal(e, a);
-    }
 }