TrimStart and TrimEnd with optional char array implementation for SQL Server

src/EFCore.SqlServer/Query/Internal/SqlServerMethodCallTranslatorProvider.cs

@@ -1,6 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using Microsoft.EntityFrameworkCore.SqlServer.Infrastructure.Internal;
+
 namespace Microsoft.EntityFrameworkCore.SqlServer.Query.Internal;
 
 /// <summary>
@@ -17,7 +19,7 @@ public class SqlServerMethodCallTranslatorProvider : RelationalMethodCallTransla
     ///     any release. You should only use it directly in your code with extreme caution and knowing that
     ///     doing so can result in application failures when updating to a new Entity Framework Core release.
     /// </summary>
-    public SqlServerMethodCallTranslatorProvider(RelationalMethodCallTranslatorProviderDependencies dependencies)
+    public SqlServerMethodCallTranslatorProvider(RelationalMethodCallTranslatorProviderDependencies dependencies, ISqlServerSingletonOptions sqlServerSingletonOptions)
         : base(dependencies)
     {
         var sqlExpressionFactory = dependencies.SqlExpressionFactory;
@@ -37,7 +39,7 @@ public SqlServerMethodCallTranslatorProvider(RelationalMethodCallTranslatorProvi
             new SqlServerMathTranslator(sqlExpressionFactory),
             new SqlServerNewGuidTranslator(sqlExpressionFactory),
             new SqlServerObjectToStringTranslator(sqlExpressionFactory, typeMappingSource),
-            new SqlServerStringMethodTranslator(sqlExpressionFactory),
+            new SqlServerStringMethodTranslator(sqlExpressionFactory, sqlServerSingletonOptions),
             new SqlServerTimeOnlyMethodTranslator(sqlExpressionFactory)
         ]);
     }

src/EFCore.SqlServer/Query/Internal/Translators/SqlServerStringMethodTranslator.cs

@@ -1,7 +1,9 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Text;
 using Microsoft.EntityFrameworkCore.Query.SqlExpressions;
+using Microsoft.EntityFrameworkCore.SqlServer.Infrastructure.Internal;
 using ExpressionExtensions = Microsoft.EntityFrameworkCore.Query.ExpressionExtensions;
 
 // ReSharper disable once CheckNamespace
@@ -62,6 +64,12 @@ private static readonly MethodInfo TrimEndMethodInfoWithCharArrayArg
     private static readonly MethodInfo TrimMethodInfoWithCharArrayArg
         = typeof(string).GetRuntimeMethod(nameof(string.Trim), [typeof(char[])])!;
 
+    private static readonly MethodInfo TrimStartMethodInfoWithCharArg
+        = typeof(string).GetRuntimeMethod(nameof(string.TrimStart), [typeof(char)])!;
+
+    private static readonly MethodInfo TrimEndMethodInfoWithCharArg
+        = typeof(string).GetRuntimeMethod(nameof(string.TrimEnd), [typeof(char)])!;
+
     private static readonly MethodInfo FirstOrDefaultMethodInfoWithoutArgs
         = typeof(Enumerable).GetRuntimeMethods().Single(
             m => m.Name == nameof(Enumerable.FirstOrDefault)
@@ -79,15 +87,19 @@ private static readonly MethodInfo PatIndexMethodInfo
 
     private readonly ISqlExpressionFactory _sqlExpressionFactory;
 
+    private readonly ISqlServerSingletonOptions _sqlServerSingletonOptions;
+
     /// <summary>
     ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
     ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
     ///     any release. You should only use it directly in your code with extreme caution and knowing that
     ///     doing so can result in application failures when updating to a new Entity Framework Core release.
     /// </summary>
-    public SqlServerStringMethodTranslator(ISqlExpressionFactory sqlExpressionFactory)
+    public SqlServerStringMethodTranslator(ISqlExpressionFactory sqlExpressionFactory, ISqlServerSingletonOptions sqlServerSingletonOptions)
     {
         _sqlExpressionFactory = sqlExpressionFactory;
+
+        _sqlServerSingletonOptions = sqlServerSingletonOptions;
     }
 
     /// <summary>
@@ -186,33 +198,22 @@ public SqlServerStringMethodTranslator(ISqlExpressionFactory sqlExpressionFactor
                     instance.TypeMapping);
             }
 
-            if (TrimStartMethodInfoWithoutArgs.Equals(method)
-                || (TrimStartMethodInfoWithCharArrayArg.Equals(method)
-                    // SqlServer LTRIM does not take arguments
-                    && ((arguments[0] as SqlConstantExpression)?.Value as Array)?.Length == 0))
+            if (_sqlServerSingletonOptions.CompatibilityLevel >= 160)
             {
-                return _sqlExpressionFactory.Function(
-                    "LTRIM",
-                    new[] { instance },
-                    nullable: true,
-                    argumentsPropagateNullability: new[] { true },
-                    instance.Type,
-                    instance.TypeMapping);
-            }
+                if (TrimStartMethodInfoWithoutArgs.Equals(method)
+                    || TrimStartMethodInfoWithCharArg.Equals(method)
+                    || TrimStartMethodInfoWithCharArrayArg.Equals(method))
+                {
+                    return ProcessTrimMethod(instance, arguments, "LTRIM");
+                }
 
-            if (TrimEndMethodInfoWithoutArgs.Equals(method)
-                || (TrimEndMethodInfoWithCharArrayArg.Equals(method)
-                    // SqlServer RTRIM does not take arguments
-                    && ((arguments[0] as SqlConstantExpression)?.Value as Array)?.Length == 0))
-            {
-                return _sqlExpressionFactory.Function(
-                    "RTRIM",
-                    new[] { instance },
-                    nullable: true,
-                    argumentsPropagateNullability: new[] { true },
-                    instance.Type,
-                    instance.TypeMapping);
-            }
+                if (TrimEndMethodInfoWithoutArgs.Equals(method)
+                    || TrimEndMethodInfoWithCharArg.Equals(method)
+                    || TrimEndMethodInfoWithCharArrayArg.Equals(method))
+                {
+                    return ProcessTrimMethod(instance, arguments, "RTRIM");
+                }
+            }            
 
             if (TrimMethodInfoWithoutArgs.Equals(method)
                 || (TrimMethodInfoWithCharArrayArg.Equals(method)
@@ -381,4 +382,46 @@ private SqlExpression TranslateIndexOf(
 
         return _sqlExpressionFactory.Subtract(charIndexExpression, offsetExpression);
     }
+
+    private SqlExpression? ProcessTrimMethod(SqlExpression instance, IReadOnlyList<SqlExpression> arguments, string functionName)
+    {
+        var typeMapping = instance.TypeMapping;
+        if (typeMapping == null)
+        {
+            return null;
+        }
+
+        var sqlArguments = new List<SqlExpression> { instance };
+        if (arguments.Count == 1)
+        {
+            var constantValue = (arguments[0] as SqlConstantExpression)?.Value;
+            var charactersToTrim = new StringBuilder();
+
+            if (constantValue is char singleChar)
+            {
+                charactersToTrim.Append(singleChar);
+            }
+            else if (constantValue is char[] charArray)
+            {
+                charactersToTrim.Append(charArray);
+            }
+            else
+            {
+                return null;
+            }
+
+            if (charactersToTrim.Length > 0)
+            {
+                sqlArguments.Add(_sqlExpressionFactory.Constant(new string(charactersToTrim.ToString()), typeMapping));
+            }
+        }
+
+        return _sqlExpressionFactory.Function(
+            functionName,
+            sqlArguments,
+            nullable: true,
+            argumentsPropagateNullability: sqlArguments.Select(_ => true).ToList(),
+            instance.Type,
+            typeMapping);
+    }
 }

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

@@ -2656,20 +2656,30 @@ WHERE LTRIM([c].[ContactTitle]) = N'Owner'
 """);
     }
 
+    [SqlServerCondition(SqlServerCondition.SupportsFunctions2022)]
     public override async Task TrimStart_with_char_argument_in_predicate(bool async)
     {
-        // String.Trim with parameters. Issue #22927.
-        await AssertTranslationFailed(() => base.TrimStart_with_char_argument_in_predicate(async));
+        await base.TrimStart_with_char_argument_in_predicate(async);
 
-        AssertSql();
+        AssertSql(
+            """
+SELECT [c].[CustomerID], [c].[Address], [c].[City], [c].[CompanyName], [c].[ContactName], [c].[ContactTitle], [c].[Country], [c].[Fax], [c].[Phone], [c].[PostalCode], [c].[Region]
+FROM [Customers] AS [c]
+WHERE LTRIM([c].[ContactTitle], N'O') = N'wner'
+""");
     }
 
+    [SqlServerCondition(SqlServerCondition.SupportsFunctions2022)]
     public override async Task TrimStart_with_char_array_argument_in_predicate(bool async)
     {
-        // String.Trim with parameters. Issue #22927.
-        await AssertTranslationFailed(() => base.TrimStart_with_char_array_argument_in_predicate(async));
+        await base.TrimStart_with_char_array_argument_in_predicate(async);
 
-        AssertSql();
+        AssertSql(
+            """
+SELECT [c].[CustomerID], [c].[Address], [c].[City], [c].[CompanyName], [c].[ContactName], [c].[ContactTitle], [c].[Country], [c].[Fax], [c].[Phone], [c].[PostalCode], [c].[Region]
+FROM [Customers] AS [c]
+WHERE LTRIM([c].[ContactTitle], N'Ow') = N'ner'
+""");
     }
 
     public override async Task TrimEnd_without_arguments_in_predicate(bool async)
@@ -2684,20 +2694,30 @@ WHERE RTRIM([c].[ContactTitle]) = N'Owner'
 """);
     }
 
+    [SqlServerCondition(SqlServerCondition.SupportsFunctions2022)]
     public override async Task TrimEnd_with_char_argument_in_predicate(bool async)
     {
-        // String.Trim with parameters. Issue #22927.
-        await AssertTranslationFailed(() => base.TrimEnd_with_char_argument_in_predicate(async));
+        await  base.TrimEnd_with_char_argument_in_predicate(async);
 
-        AssertSql();
+        AssertSql(
+           """
+SELECT [c].[CustomerID], [c].[Address], [c].[City], [c].[CompanyName], [c].[ContactName], [c].[ContactTitle], [c].[Country], [c].[Fax], [c].[Phone], [c].[PostalCode], [c].[Region]
+FROM [Customers] AS [c]
+WHERE RTRIM([c].[ContactTitle], N'r') = N'Owne'
+""");
     }
 
+    [SqlServerCondition(SqlServerCondition.SupportsFunctions2022)]
     public override async Task TrimEnd_with_char_array_argument_in_predicate(bool async)
     {
-        // String.Trim with parameters. Issue #22927.
-        await AssertTranslationFailed(() => base.TrimEnd_with_char_array_argument_in_predicate(async));
+        await base.TrimEnd_with_char_array_argument_in_predicate(async);
 
-        AssertSql();
+        AssertSql(
+           """
+SELECT [c].[CustomerID], [c].[Address], [c].[City], [c].[CompanyName], [c].[ContactName], [c].[ContactTitle], [c].[Country], [c].[Fax], [c].[Phone], [c].[PostalCode], [c].[Region]
+FROM [Customers] AS [c]
+WHERE RTRIM([c].[ContactTitle], N'er') = N'Own'
+""");
     }
 
     public override async Task Trim_without_argument_in_predicate(bool async)