dotnet · smitpatel · Aug 23, 2021 · Aug 23, 2021
diff --git a/src/EFCore.Cosmos/Query/Internal/CosmosSqlTranslatingExpressionVisitor.cs b/src/EFCore.Cosmos/Query/Internal/CosmosSqlTranslatingExpressionVisitor.cs
@@ -766,7 +766,7 @@ when sqlParameterExpression.Name.StartsWith(QueryCompilationContext.QueryParamet
 
                     var newParameterName =
                         $"{_runtimeParameterPrefix}"
-                        + $"{sqlParameterExpression.Name.Substring(QueryCompilationContext.QueryParameterPrefix.Length)}_{property.Name}";
+                        + $"{sqlParameterExpression.Name[QueryCompilationContext.QueryParameterPrefix.Length..]}_{property.Name}";
 
                     rewrittenSource = _queryCompilationContext.RegisterRuntimeParameter(newParameterName, lambda);
                     break;
@@ -880,7 +880,7 @@ when sqlParameterExpression.Name.StartsWith(QueryCompilationContext.QueryParamet
 
                     var newParameterName =
                         $"{_runtimeParameterPrefix}"
-                        + $"{sqlParameterExpression.Name.Substring(QueryCompilationContext.QueryParameterPrefix.Length)}_{property.Name}";
+                        + $"{sqlParameterExpression.Name[QueryCompilationContext.QueryParameterPrefix.Length..]}_{property.Name}";
 
                     return _queryCompilationContext.RegisterRuntimeParameter(newParameterName, lambda);
 

diff --git a/src/EFCore.Relational/Query/RelationalSqlTranslatingExpressionVisitor.cs b/src/EFCore.Relational/Query/RelationalSqlTranslatingExpressionVisitor.cs
@@ -1254,7 +1254,7 @@ when sqlParameterExpression.Name.StartsWith(QueryCompilationContext.QueryParamet
 
                     var newParameterName =
                         $"{RuntimeParameterPrefix}"
-                        + $"{sqlParameterExpression.Name.Substring(QueryCompilationContext.QueryParameterPrefix.Length)}_{property.Name}";
+                        + $"{sqlParameterExpression.Name[QueryCompilationContext.QueryParameterPrefix.Length..]}_{property.Name}";
 
                     return _queryCompilationContext.RegisterRuntimeParameter(newParameterName, lambda);
 

diff --git a/src/EFCore/Diagnostics/LoggerCategory.cs b/src/EFCore/Diagnostics/LoggerCategory.cs
@@ -40,7 +40,7 @@ private static string ToName(Type loggerCategoryType)
             var index = name.IndexOf(outerClassName, StringComparison.Ordinal);
             if (index >= 0)
             {
-                name = name.Substring(0, index) + name.Substring(index + outerClassName.Length);
+                name = name.Substring(0, index) + name[(index + outerClassName.Length)..];
             }
 
             return name;

diff --git a/src/EFCore/Properties/CoreStrings.Designer.cs b/src/EFCore/Properties/CoreStrings.Designer.cs
diff --git a/src/EFCore/Properties/CoreStrings.resx b/src/EFCore/Properties/CoreStrings.resx
@@ -1313,6 +1313,9 @@
   <data name="QueryRootDifferentEntityType" xml:space="preserve">
     <value>The replacement entity type: {entityType} does not have same name and CLR type as entity type this query root represents.</value>
   </data>
+  <data name="QuerySelectContainsGrouping" xml:space="preserve">
+    <value>Translation of 'Select' which contains grouping parameter without composition is not supported.</value>
+  </data>
   <data name="QueryUnableToTranslateEFProperty" xml:space="preserve">
     <value>Translation of '{expression}' failed. Either the query source is not an entity type, or the specified property does not exist on the entity type.</value>
   </data>

diff --git a/src/EFCore/Query/Internal/NavigationExpandingExpressionVisitor.ExpressionVisitors.cs b/src/EFCore/Query/Internal/NavigationExpandingExpressionVisitor.ExpressionVisitors.cs
@@ -1144,24 +1144,40 @@ public GroupingElementReplacingExpressionVisitor(
                 _cloningExpressionVisitor = new CloningExpressionVisitor();
             }
 
+            public bool ContainsGrouping { get; private set; }
+
             [return: NotNullIfNotNull("expression")]
             public override Expression? Visit(Expression? expression)
             {
                 if (expression == _parameterExpression)
+                {
+                    ContainsGrouping = true;
+                }
+
+                return base.Visit(expression);
+            }
+
+            protected override Expression VisitMethodCall(MethodCallExpression methodCallExpression)
+            {
+                if (methodCallExpression.Method.IsGenericMethod
+                    && methodCallExpression.Method.GetGenericMethodDefinition() == QueryableMethods.AsQueryable
+                    && methodCallExpression.Arguments[0] == _parameterExpression)
                 {
                     var currentTree = _cloningExpressionVisitor.Clone(_navigationExpansionExpression.CurrentTree);
 
-                    return new NavigationExpansionExpression(
+                    var navigationExpansionExpression = new NavigationExpansionExpression(
                         _navigationExpansionExpression.Source,
                         currentTree,
                         new ReplacingExpressionVisitor(
                             _cloningExpressionVisitor.ClonedNodesMap.Keys.ToList(),
                             _cloningExpressionVisitor.ClonedNodesMap.Values.ToList())
                             .Visit(_navigationExpansionExpression.PendingSelector),
                         _navigationExpansionExpression.CurrentParameter.Name!);
+
+                    return methodCallExpression.Update(null, new[] { navigationExpansionExpression });
                 }
 
-                return base.Visit(expression);
+                return base.VisitMethodCall(methodCallExpression);
             }
 
             protected override Expression VisitMember(MemberExpression memberExpression)

diff --git a/src/EFCore/Query/Internal/NavigationExpandingExpressionVisitor.cs b/src/EFCore/Query/Internal/NavigationExpandingExpressionVisitor.cs
@@ -645,9 +645,18 @@ when QueryableMethods.IsSumWithSelector(method):
 
                         case nameof(Queryable.Select)
                             when genericMethod == QueryableMethods.Select:
-                            return ProcessSelect(
+                            var result = ProcessSelect(
                                 groupBySource,
                                 methodCallExpression.Arguments[1].UnwrapLambdaFromQuote());
+                            if (result == null)
+                            {
+                                throw new InvalidOperationException(
+                                    CoreStrings.TranslationFailedWithDetails(
+                                        _reducingExpressionVisitor.Visit(methodCallExpression).Print(),
+                                        CoreStrings.QuerySelectContainsGrouping));
+                            }
+
+                            return result;
 
                         case nameof(Queryable.Skip)
                             when genericMethod == QueryableMethods.Skip:
@@ -1449,9 +1458,14 @@ private GroupByNavigationExpansionExpression ProcessOrderByThenBy(
             return groupBySource;
         }
 
-        private NavigationExpansionExpression ProcessSelect(GroupByNavigationExpansionExpression groupBySource, LambdaExpression selector)
+        private NavigationExpansionExpression? ProcessSelect(GroupByNavigationExpansionExpression groupBySource, LambdaExpression selector)
         {
-            var selectorBody = new GroupingElementReplacingExpressionVisitor(selector.Parameters[0], groupBySource).Visit(selector.Body);
+            var groupingElementReplacingExpressionVisitor = new GroupingElementReplacingExpressionVisitor(selector.Parameters[0], groupBySource);
+            var selectorBody = groupingElementReplacingExpressionVisitor.Visit(selector.Body);
+            if (groupingElementReplacingExpressionVisitor.ContainsGrouping)
+            {
+                return null;
+            }
             selectorBody = Visit(selectorBody);
             selectorBody = new PendingSelectorExpandingExpressionVisitor(this, _extensibilityHelper, applyIncludes: true).Visit(selectorBody);
             selectorBody = Reduce(selectorBody);

diff --git a/src/EFCore/Query/Internal/ParameterExtractingExpressionVisitor.cs b/src/EFCore/Query/Internal/ParameterExtractingExpressionVisitor.cs
@@ -342,7 +342,7 @@ var compilerPrefixIndex
 
             if (compilerPrefixIndex != -1)
             {
-                parameterName = parameterName.Substring(compilerPrefixIndex + 1);
+                parameterName = parameterName[(compilerPrefixIndex + 1)..];
             }
 
             parameterName

diff --git a/test/EFCore.Cosmos.FunctionalTests/CustomConvertersCosmosTest.cs b/test/EFCore.Cosmos.FunctionalTests/CustomConvertersCosmosTest.cs
@@ -155,7 +155,7 @@ public override void Optional_owned_with_converter_reading_non_nullable_column()
         public override void Value_conversion_on_enum_collection_contains()
         {
             Assert.Contains(
-                CoreStrings.TranslationFailed("").Substring(47),
+                CoreStrings.TranslationFailed("")[47..],
                 Assert.Throws<InvalidOperationException>(() => base.Value_conversion_on_enum_collection_contains()).Message);
         }
 

diff --git a/test/EFCore.Cosmos.FunctionalTests/TestUtilities/TestSqlLoggerFactory.cs b/test/EFCore.Cosmos.FunctionalTests/TestUtilities/TestSqlLoggerFactory.cs
@@ -66,7 +66,7 @@ public void AssertBaseline(string[] expected, bool assertOrder = true)
             {
                 var methodCallLine = Environment.StackTrace.Split(
                     new[] { _eol },
-                    StringSplitOptions.RemoveEmptyEntries)[3].Substring(6);
+                    StringSplitOptions.RemoveEmptyEntries)[3][6..];
 
                 var indexMethodEnding = methodCallLine.IndexOf(')') + 1;
                 var testName = methodCallLine.Substring(0, indexMethodEnding);

diff --git a/test/EFCore.Relational.Specification.Tests/Query/QueryNoClientEvalTestBase.cs b/test/EFCore.Relational.Specification.Tests/Query/QueryNoClientEvalTestBase.cs
@@ -200,12 +200,12 @@ private string NormalizeDelimitersInRawString(string sql)
 
         private void AssertTranslationFailed(Action testCode)
             => Assert.Contains(
-                CoreStrings.TranslationFailed("").Substring(21),
+                CoreStrings.TranslationFailed("")[21..],
                 Assert.Throws<InvalidOperationException>(testCode).Message);
 
         private void AssertTranslationFailedWithDetails(Action testCode, string details)
             => Assert.Contains(
-                CoreStrings.TranslationFailedWithDetails("", details).Substring(21),
+                CoreStrings.TranslationFailedWithDetails("", details)[21..],
                 Assert.Throws<InvalidOperationException>(testCode).Message);
 
         protected NorthwindContext CreateContext()

diff --git a/test/EFCore.Relational.Specification.Tests/Query/UdfDbFunctionTestBase.cs b/test/EFCore.Relational.Specification.Tests/Query/UdfDbFunctionTestBase.cs
@@ -2160,7 +2160,7 @@ protected virtual void ClearLog()
 
         private void AssertTranslationFailed(Action testCode)
             => Assert.Contains(
-                CoreStrings.TranslationFailed("").Substring(48),
+                CoreStrings.TranslationFailed("")[48..],
                 Assert.Throws<InvalidOperationException>(testCode).Message);
     }
 }
diff --git a/test/EFCore.Relational.Specification.Tests/TestUtilities/TestSqlLoggerFactory.cs b/test/EFCore.Relational.Specification.Tests/TestUtilities/TestSqlLoggerFactory.cs
@@ -76,7 +76,7 @@ public void AssertBaseline(string[] expected, bool assertOrder = true)
             {
                 var methodCallLine = Environment.StackTrace.Split(
                     new[] { _eol },
-                    StringSplitOptions.RemoveEmptyEntries)[3].Substring(6);
+                    StringSplitOptions.RemoveEmptyEntries)[3][6..];
 
                 var indexMethodEnding = methodCallLine.IndexOf(')') + 1;
                 var testName = methodCallLine.Substring(0, indexMethodEnding);

diff --git a/test/EFCore.Specification.Tests/Query/NorthwindGroupByQueryTestBase.cs b/test/EFCore.Specification.Tests/Query/NorthwindGroupByQueryTestBase.cs
@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
+using Microsoft.EntityFrameworkCore.Diagnostics;
 using Microsoft.EntityFrameworkCore.TestModels.Northwind;
 using Microsoft.EntityFrameworkCore.TestUtilities;
 using Xunit;
@@ -2458,6 +2459,41 @@ public virtual Task GroupBy_aggregate_followed_another_GroupBy_aggregate(bool as
                 elementSorter: o => o.Key);
         }
 
+        [ConditionalTheory]
+        [MemberData(nameof(IsAsyncData))]
+        public virtual async Task GroupBy_aggregate_SelectMany(bool async)
+        {
+            var message = (await Assert.ThrowsAsync<InvalidOperationException>(
+                () => AssertQuery(
+                    async,
+                    ss => from o in ss.Set<Order>()
+                          group o by o.CustomerID into g
+                          let id = g.Min(x => x.OrderID)
+                          from o in ss.Set<Order>()
+                          where o.OrderID == id
+                          select o))).Message;
+
+            Assert.Contains(
+                CoreStrings.TranslationFailedWithDetails("", CoreStrings.QuerySelectContainsGrouping)[21..],
+                message);
+        }
+
+        [ConditionalTheory]
+        [MemberData(nameof(IsAsyncData))]
+        public virtual Task GroupBy_aggregate_without_selectMany_selecting_first(bool async)
+        {
+            return AssertQuery(
+                async,
+                ss => from id in
+                          (from o in ss.Set<Order>()
+                            group o by o.CustomerID into g
+                            select g.Min(x => x.OrderID))
+                      from o in ss.Set<Order>()
+                      where o.OrderID == id
+                      select o,
+                entryCount: 89);
+        }
+
         #endregion
 
         #region GroupByAggregateChainComposition

diff --git a/test/EFCore.Specification.Tests/Query/NorthwindIncludeQueryTestBase.cs b/test/EFCore.Specification.Tests/Query/NorthwindIncludeQueryTestBase.cs
@@ -716,7 +716,7 @@ public virtual async Task Include_collection_with_client_filter(bool async)
             Assert.Contains(
                 CoreStrings.TranslationFailedWithDetails(
                     "",
-                    CoreStrings.QueryUnableToTranslateMember(nameof(Customer.IsLondon), nameof(Customer))).Substring(21),
+                    CoreStrings.QueryUnableToTranslateMember(nameof(Customer.IsLondon), nameof(Customer)))[21..],
                 (await Assert.ThrowsAsync<InvalidOperationException>(
                     () => AssertQuery(
                         async,

diff --git a/test/EFCore.Specification.Tests/Query/QueryTestBase.cs b/test/EFCore.Specification.Tests/Query/QueryTestBase.cs
@@ -1131,13 +1131,13 @@ protected void AssertGrouping<TKey, TElement>(
 
         protected static async Task AssertTranslationFailed(Func<Task> query)
             => Assert.Contains(
-                CoreStrings.TranslationFailed("").Substring(48),
+                CoreStrings.TranslationFailed("")[48..],
                 (await Assert.ThrowsAsync<InvalidOperationException>(query))
                 .Message);
 
         protected static async Task AssertTranslationFailedWithDetails(Func<Task> query, string details)
             => Assert.Contains(
-                CoreStrings.TranslationFailedWithDetails("", details).Substring(21),
+                CoreStrings.TranslationFailedWithDetails("", details)[21..],
                 (await Assert.ThrowsAsync<InvalidOperationException>(query))
                 .Message);
 

diff --git a/test/EFCore.SqlServer.FunctionalTests/CustomConvertersSqlServerTest.cs b/test/EFCore.SqlServer.FunctionalTests/CustomConvertersSqlServerTest.cs
@@ -295,7 +295,7 @@ FROM [Book] AS [b]
         public override void Value_conversion_on_enum_collection_contains()
         {
             Assert.Contains(
-                CoreStrings.TranslationFailed("").Substring(47),
+                CoreStrings.TranslationFailed("")[47..],
                 Assert.Throws<InvalidOperationException>(() => base.Value_conversion_on_enum_collection_contains()).Message);
         }
 

diff --git a/test/EFCore.SqlServer.FunctionalTests/LoadSqlServerTest.cs b/test/EFCore.SqlServer.FunctionalTests/LoadSqlServerTest.cs
@@ -1471,11 +1471,11 @@ private void AssertSql(string expected)
             {
                 var methodCallLine = Environment.StackTrace.Split(
                     new[] { Environment.NewLine },
-                    StringSplitOptions.RemoveEmptyEntries)[2].Substring(6);
+                    StringSplitOptions.RemoveEmptyEntries)[2][6..];
 
                 var testName = methodCallLine.Substring(0, methodCallLine.IndexOf(')') + 1);
                 var lineIndex = methodCallLine.LastIndexOf("line", StringComparison.Ordinal);
-                var lineNumber = lineIndex > 0 ? methodCallLine.Substring(lineIndex) : "";
+                var lineNumber = lineIndex > 0 ? methodCallLine[lineIndex..] : "";
 
                 var currentDirectory = Directory.GetCurrentDirectory();
                 var logFile = currentDirectory.Substring(

diff --git a/test/EFCore.SqlServer.FunctionalTests/ManyToManyFieldsLoadSqlServerTest.cs b/test/EFCore.SqlServer.FunctionalTests/ManyToManyFieldsLoadSqlServerTest.cs
@@ -236,7 +236,7 @@ private void AssertSql(string expected)
             {
                 var methodCallLine = Environment.StackTrace.Split(
                     new[] { Environment.NewLine },
-                    StringSplitOptions.RemoveEmptyEntries)[2].Substring(6);
+                    StringSplitOptions.RemoveEmptyEntries)[2][6..];
 
                 var indexMethodEnding = methodCallLine.IndexOf(')') + 1;
                 var testName = methodCallLine.Substring(0, indexMethodEnding);

diff --git a/test/EFCore.SqlServer.FunctionalTests/ManyToManyLoadSqlServerTest.cs b/test/EFCore.SqlServer.FunctionalTests/ManyToManyLoadSqlServerTest.cs
@@ -235,7 +235,7 @@ private void AssertSql(string expected)
             {
                 var methodCallLine = Environment.StackTrace.Split(
                     new[] { Environment.NewLine },
-                    StringSplitOptions.RemoveEmptyEntries)[2].Substring(6);
+                    StringSplitOptions.RemoveEmptyEntries)[2][6..];
 
                 var indexMethodEnding = methodCallLine.IndexOf(')') + 1;
                 var testName = methodCallLine.Substring(0, indexMethodEnding);

diff --git a/test/EFCore.SqlServer.FunctionalTests/Query/NorthwindGroupByQuerySqlServerTest.cs b/test/EFCore.SqlServer.FunctionalTests/Query/NorthwindGroupByQuerySqlServerTest.cs
@@ -2442,6 +2442,21 @@ FROM [Orders] AS [o]
 GROUP BY [t].[CustomerID]");
         }
 
+        public override async Task GroupBy_aggregate_without_selectMany_selecting_first(bool async)
+        {
+            await base.GroupBy_aggregate_without_selectMany_selecting_first(async);
+
+            AssertSql(
+                @"SELECT [o0].[OrderID], [o0].[CustomerID], [o0].[EmployeeID], [o0].[OrderDate]
+FROM (
+    SELECT MIN([o].[OrderID]) AS [c]
+    FROM [Orders] AS [o]
+    GROUP BY [o].[CustomerID]
+) AS [t]
+CROSS JOIN [Orders] AS [o0]
+WHERE [o0].[OrderID] = [t].[c]");
+        }
+
         public override async Task GroupBy_with_grouping_key_using_Like(bool async)
         {
             await base.GroupBy_with_grouping_key_using_Like(async);

diff --git a/test/EFCore.Sqlite.FunctionalTests/BuiltInDataTypesSqliteTest.cs b/test/EFCore.Sqlite.FunctionalTests/BuiltInDataTypesSqliteTest.cs
@@ -1644,7 +1644,7 @@ CROSS JOIN ""BuiltInDataTypes"" AS ""b0""
 
         private void AssertTranslationFailed(Action testCode)
             => Assert.Contains(
-                CoreStrings.TranslationFailed("").Substring(21),
+                CoreStrings.TranslationFailed("")[21..],
                 Assert.Throws<InvalidOperationException>(testCode).Message);
 
         private void AssertSql(params string[] expected)

diff --git a/test/EFCore.Sqlite.FunctionalTests/CustomConvertersSqliteTest.cs b/test/EFCore.Sqlite.FunctionalTests/CustomConvertersSqliteTest.cs
@@ -119,7 +119,7 @@ public override void Where_bool_gets_converted_to_equality_when_value_conversion
         public override void Value_conversion_on_enum_collection_contains()
         {
             Assert.Contains(
-                CoreStrings.TranslationFailed("").Substring(47),
+                CoreStrings.TranslationFailed("")[47..],
                 Assert.Throws<InvalidOperationException>(() => base.Value_conversion_on_enum_collection_contains()).Message);
         }