Query: Apply pending selector on single result query before trying to…

… expand collection navigation (#21690)

Issue: We expand collection navigation when subquery terminates on single result returning. This logic did not apply pending selector. So if the pending selector had another navigation (always reference) which needs to be expanded then we failed to expand collection navigation.

Resolves #13220

src/EFCore/Query/Internal/NavigationExpandingExpressionVisitor.cs

@@ -220,6 +220,7 @@ protected override Expression VisitMember(MemberExpression memberExpression)
             {
                 // This is FirstOrDefault.Member
                 // due to SubqueryMemberPushdown, this may be collection navigation which was not pushed down
+                navigationExpansionExpression = (NavigationExpansionExpression)_pendingSelectorExpandingExpressionVisitor.Visit(navigationExpansionExpression);
                 var expandedExpression = new ExpandingExpressionVisitor(this, navigationExpansionExpression).Visit(updatedExpression);
                 if (expandedExpression != updatedExpression)
                 {

test/EFCore.Cosmos.FunctionalTests/Query/NorthwindMiscellaneousQueryCosmosTest.cs

@@ -4163,6 +4163,12 @@ public override Task Max_on_empty_sequence_throws(bool async)
             return base.Max_on_empty_sequence_throws(async);
         }
 
+        [ConditionalTheory(Skip = "Non embedded collection subquery Issue#17246")]
+        public override Task Pending_selector_in_cardinality_reducing_method_is_applied_before_expanding_collection_navigation_member(bool async)
+        {
+            return base.Pending_selector_in_cardinality_reducing_method_is_applied_before_expanding_collection_navigation_member(async);
+        }
+
         private void AssertSql(params string[] expected)
             => Fixture.TestSqlLoggerFactory.AssertBaseline(expected);
 

test/EFCore.Specification.Tests/Query/NorthwindMiscellaneousQueryTestBase.cs

@@ -6074,5 +6074,30 @@ public virtual async Task Max_on_empty_sequence_throws(bool async)
 
             Assert.Equal("Nullable object must have a value.", message);
         }
+
+        [ConditionalTheory]
+        [MemberData(nameof(IsAsyncData))]
+        public virtual Task Pending_selector_in_cardinality_reducing_method_is_applied_before_expanding_collection_navigation_member(bool async)
+        {
+            return AssertQuery(
+                async,
+                ss => ss.Set<Customer>()
+                        .Where(c => c.CustomerID.StartsWith("F"))
+                        .OrderBy(c => c.CustomerID)
+                        .Select(c => new
+                        {
+                            Complex = (bool?)c.Orders.OrderBy(e => e.OrderDate).FirstOrDefault().Customer.Orders.Any(e => e.OrderID < 11000)
+                        }),
+                ss => ss.Set<Customer>()
+                        .Where(c => c.CustomerID.StartsWith("F"))
+                        .OrderBy(c => c.CustomerID)
+                        .Select(c => new
+                        {
+                            Complex = c.Orders.OrderBy(e => e.OrderDate).FirstOrDefault() != null
+                                ? c.Orders.OrderBy(e => e.OrderDate).FirstOrDefault().Customer.Orders.Any(e => e.OrderID < 11000)
+                                : (bool?)false
+                        }),
+                assertOrder: true);
+        }
     }
 }

test/EFCore.SqlServer.FunctionalTests/Query/NorthwindMiscellaneousQuerySqlServerTest.cs

@@ -5190,6 +5190,38 @@ FROM [Customers] AS [c]
 ORDER BY [c].[CustomerID]");
         }
 
+        public override async Task Pending_selector_in_cardinality_reducing_method_is_applied_before_expanding_collection_navigation_member(bool async)
+        {
+            await base.Pending_selector_in_cardinality_reducing_method_is_applied_before_expanding_collection_navigation_member(async);
+
+            AssertSql(
+                @"SELECT CASE
+    WHEN EXISTS (
+        SELECT 1
+        FROM [Orders] AS [o]
+        WHERE ((
+            SELECT TOP(1) [c].[CustomerID]
+            FROM [Orders] AS [o0]
+            LEFT JOIN [Customers] AS [c] ON [o0].[CustomerID] = [c].[CustomerID]
+            WHERE [c1].[CustomerID] = [o0].[CustomerID]
+            ORDER BY [o0].[OrderDate]) IS NOT NULL AND (((
+            SELECT TOP(1) [c0].[CustomerID]
+            FROM [Orders] AS [o1]
+            LEFT JOIN [Customers] AS [c0] ON [o1].[CustomerID] = [c0].[CustomerID]
+            WHERE [c1].[CustomerID] = [o1].[CustomerID]
+            ORDER BY [o1].[OrderDate]) = [o].[CustomerID]) OR ((
+            SELECT TOP(1) [c0].[CustomerID]
+            FROM [Orders] AS [o1]
+            LEFT JOIN [Customers] AS [c0] ON [o1].[CustomerID] = [c0].[CustomerID]
+            WHERE [c1].[CustomerID] = [o1].[CustomerID]
+            ORDER BY [o1].[OrderDate]) IS NULL AND [o].[CustomerID] IS NULL))) AND ([o].[OrderID] < 11000)) THEN CAST(1 AS bit)
+    ELSE CAST(0 AS bit)
+END AS [Complex]
+FROM [Customers] AS [c1]
+WHERE [c1].[CustomerID] LIKE N'F%'
+ORDER BY [c1].[CustomerID]");
+        }
+
         private void AssertSql(params string[] expected)
             => Fixture.TestSqlLoggerFactory.AssertBaseline(expected);