Support ref/out parameters which return list

SqlMarshal.CompilationTests/ConnectionManager.cs

@@ -22,6 +22,9 @@ public ConnectionManager(SqlConnection connection)
     [SqlMarshal("persons_list")]
     public partial IList<PersonInformation> GetResult();
 
+    [SqlMarshal("persons_list")]
+    public partial void GetResultWithOut(out IList<PersonInformation> result);
+
     [SqlMarshal("persons_list")]
     public partial IList<(int Id, string Name)> GetTupleResult();
 

SqlMarshal.CompilationTests/Program.cs

@@ -86,6 +86,13 @@ private static void TestConnectionManager(ConnectionManager connectionManager)
             WritePerson(personInfo);
         }
 
+        connectionManager.GetResultWithOut(out var samePersons);
+        WriteLine("Same 10 rows from persons_list SP using out parameter");
+        foreach (var personInfo in persons.Take(10))
+        {
+            WritePerson(personInfo);
+        }
+
         var persons2 = connectionManager.GetResultByPage(2, out var totalCount);
         WriteLine("Print results of persons_by_page SP");
         foreach (var personInfo in persons2)

SqlMarshal.Tests/SqlConnectionTests.cs

@@ -282,6 +282,148 @@ partial class C
         Assert.AreEqual(expectedOutput, output);
     }
 
+    [TestMethod]
+    public void MapResultSetToProcedureWithOutParameter()
+    {
+        string source = @"
+namespace Foo
+{
+    public class Item
+    {
+        public string StringValue { get; set; }
+        public int Int32Value { get; set; }
+        public int? NullableInt32Value { get; set; }
+    }
+
+    class C
+    {
+        private DbConnection connection;
+
+        [SqlMarshal(""sp_TestSP"")]
+        public partial void M(out IList<Item> result)
+    }
+}";
+        string output = this.GetGeneratedOutput(source, NullableContextOptions.Disable);
+
+        Assert.IsNotNull(output);
+
+        var expectedOutput = @"// <auto-generated>
+// Code generated by Stored Procedures Code Generator.
+// Changes may cause incorrect behavior and will be lost if the code is
+// regenerated.
+// </auto-generated>
+#nullable enable
+#pragma warning disable 1591
+
+namespace Foo
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Data.Common;
+    using System.Linq;
+
+    partial class C
+    {
+        public partial void M(out IList<Foo.Item> result)
+        {
+            var connection = this.connection;
+            using var command = connection.CreateCommand();
+
+            var sqlQuery = @""sp_TestSP"";
+            command.CommandText = sqlQuery;
+            using var reader = command.ExecuteReader();
+            var __result = new List<Item>();
+            while (reader.Read())
+            {
+                var item = new Item();
+                var value_0 = reader.GetValue(0);
+                item.StringValue = value_0 == DBNull.Value ? (string?)null : (string)value_0;
+                var value_1 = reader.GetValue(1);
+                item.Int32Value = (int)value_1;
+                var value_2 = reader.GetValue(2);
+                item.NullableInt32Value = value_2 == DBNull.Value ? (int?)null : (int)value_2;
+                __result.Add(item);
+            }
+
+            reader.Close();
+            result = __result;
+        }
+    }
+}";
+        Assert.AreEqual(expectedOutput, output);
+    }
+
+    [TestMethod]
+    public void MapResultSetToProcedureWithRefParameter()
+    {
+        string source = @"
+namespace Foo
+{
+    public class Item
+    {
+        public string StringValue { get; set; }
+        public int Int32Value { get; set; }
+        public int? NullableInt32Value { get; set; }
+    }
+
+    class C
+    {
+        private DbConnection connection;
+
+        [SqlMarshal(""sp_TestSP"")]
+        public partial void M(ref IList<Item> result)
+    }
+}";
+        string output = this.GetGeneratedOutput(source, NullableContextOptions.Disable);
+
+        Assert.IsNotNull(output);
+
+        var expectedOutput = @"// <auto-generated>
+// Code generated by Stored Procedures Code Generator.
+// Changes may cause incorrect behavior and will be lost if the code is
+// regenerated.
+// </auto-generated>
+#nullable enable
+#pragma warning disable 1591
+
+namespace Foo
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Data.Common;
+    using System.Linq;
+
+    partial class C
+    {
+        public partial void M(ref IList<Foo.Item> result)
+        {
+            var connection = this.connection;
+            using var command = connection.CreateCommand();
+
+            var sqlQuery = @""sp_TestSP"";
+            command.CommandText = sqlQuery;
+            using var reader = command.ExecuteReader();
+            var __result = result ?? new List<Item>();
+            while (reader.Read())
+            {
+                var item = new Item();
+                var value_0 = reader.GetValue(0);
+                item.StringValue = value_0 == DBNull.Value ? (string?)null : (string)value_0;
+                var value_1 = reader.GetValue(1);
+                item.Int32Value = (int)value_1;
+                var value_2 = reader.GetValue(2);
+                item.NullableInt32Value = value_2 == DBNull.Value ? (int?)null : (int)value_2;
+                __result.Add(item);
+            }
+
+            reader.Close();
+            result = __result;
+        }
+    }
+}";
+        Assert.AreEqual(expectedOutput, output);
+    }
+
     [TestMethod]
     public void MapSingleObjectToProcedureConnection()
     {

SqlMarshal.Tests/StoredProcedureGenerationTests.cs

@@ -1624,6 +1624,68 @@ partial class C
             }
         }
     }
+}";
+        Assert.AreEqual(expectedOutput, output);
+    }
+
+    [TestMethod]
+    public void MapListWithOtputParameter()
+    {
+        string source = @"
+namespace Foo
+{
+    class C
+    {
+        [SqlMarshal(""sp_TestSP"")]
+        public partial void M(int clientId, int? personId, out IList<Item> result)
+    }
+}";
+        string output = this.GetGeneratedOutput(source, NullableContextOptions.Disable);
+
+        Assert.IsNotNull(output);
+
+        var expectedOutput = @"// <auto-generated>
+// Code generated by Stored Procedures Code Generator.
+// Changes may cause incorrect behavior and will be lost if the code is
+// regenerated.
+// </auto-generated>
+#nullable enable
+#pragma warning disable 1591
+
+namespace Foo
+{
+    using System;
+    using System.Data.Common;
+    using System.Linq;
+    using Microsoft.EntityFrameworkCore;
+    using Microsoft.EntityFrameworkCore.Storage;
+
+    partial class C
+    {
+        public partial void M(int clientId, int? personId, out IList<Item> result)
+        {
+            var connection = this.dbContext.Database.GetDbConnection();
+            using var command = connection.CreateCommand();
+
+            var clientIdParameter = command.CreateParameter();
+            clientIdParameter.ParameterName = ""@client_id"";
+            clientIdParameter.Value = clientId;
+
+            var personIdParameter = command.CreateParameter();
+            personIdParameter.ParameterName = ""@person_id"";
+            personIdParameter.Value = personId == null ? (object)DBNull.Value : personId;
+
+            var parameters = new DbParameter[]
+            {
+                clientIdParameter,
+                personIdParameter,
+            };
+
+            var sqlQuery = @""sp_TestSP @client_id, @person_id"";
+            var __result = this.dbContext.Items.FromSqlRaw(sqlQuery, parameters).ToList();
+            result = __result;
+        }
+    }
 }";
         Assert.AreEqual(expectedOutput, output);
     }

SqlMarshal/Extensions.cs

@@ -153,7 +153,7 @@ internal static ITypeSymbol GetUnderlyingType(ITypeSymbol returnType)
         return returnType;
     }
 
-    internal static bool IsList(ITypeSymbol returnType) => returnType.Name == "IList" || returnType.Name == "List";
+    internal static bool IsList(this ITypeSymbol returnType) => returnType.Name == "IList" || returnType.Name == "List";
 
     internal static bool IsEnumerable(ITypeSymbol returnType) => returnType.Name == "IEnumerable";
 

SqlMarshal/Generator.cs

@@ -616,7 +616,7 @@ private void MapResults(
 
             if (isList)
             {
-                source.AppendLine($@"var __result = new List<{(IsTuple(itemType) ? itemType.ToDisplayString() : itemType.Name)}>();");
+                source.AppendLine($@"var __result = {(methodGenerationContext.OutputResultsetParameter?.RefKind == RefKind.Ref ? $"{methodGenerationContext.OutputResultsetParameter.Name} ?? " : string.Empty)}new List<{(IsTuple(itemType) ? itemType.ToDisplayString() : itemType.Name)}>();");
                 if (isTask)
                 {
                     source.AppendLine($"while (await reader.ReadAsync({cancellationToken}).ConfigureAwait(false))");
@@ -1106,7 +1106,14 @@ private void ProcessMethod(
             {
                 this.MapResults(source, methodGenerationContext, methodSymbol, parameters, itemType, hasNullableAnnotations, isList, isTask);
                 MarshalOutputParameters(source, parameters, hasNullableAnnotations);
-                source.AppendLine(ReturnStatement(IdentifierName("__result")).NormalizeWhitespace().ToFullString());
+                if (methodGenerationContext.OutputResultsetParameter != null)
+                {
+                    source.AppendLine($"{methodGenerationContext.OutputResultsetParameter.Name} = __result;");
+                }
+                else
+                {
+                    source.AppendLine(ReturnStatement(IdentifierName("__result")).NormalizeWhitespace().ToFullString());
+                }
             }
         }
 

SqlMarshal/MethodGenerationContext.cs

@@ -23,12 +23,18 @@ internal MethodGenerationContext(ClassGenerationContext classGenerationContext,
         this.DbContextParameter = GetDbContextParameter(methodSymbol);
         this.CustomSqlParameter = GetCustomSqlParameter(methodSymbol);
         this.CancellationTokenParameter = GetCancellationTokenParameter(methodSymbol);
+        this.OutputResultsetParameter = GetOutputResultsetParameter(methodSymbol);
         var parameters = methodSymbol.Parameters;
         if (this.ConnectionParameter != null)
         {
             parameters = parameters.Remove(this.ConnectionParameter);
         }
 
+        if (this.OutputResultsetParameter != null)
+        {
+            parameters = parameters.Remove(this.OutputResultsetParameter);
+        }
+
         if (this.DbContextParameter != null)
         {
             parameters = parameters.Remove(this.DbContextParameter);
@@ -60,6 +66,8 @@ internal MethodGenerationContext(ClassGenerationContext classGenerationContext,
 
     internal IParameterSymbol? ConnectionParameter { get; }
 
+    internal IParameterSymbol? OutputResultsetParameter { get; }
+
     internal IParameterSymbol? TransactionParameter { get; }
 
     internal IParameterSymbol? DbContextParameter { get; }
@@ -74,9 +82,9 @@ internal MethodGenerationContext(ClassGenerationContext classGenerationContext,
 
     internal bool IsDataReader => this.MethodSymbol.ReturnType.Name == "DbDataReader";
 
-    internal ITypeSymbol ReturnType => this.MethodSymbol.ReturnType.UnwrapTaskType();
+    internal ITypeSymbol ReturnType => this.OutputResultsetParameter?.Type ?? this.MethodSymbol.ReturnType.UnwrapTaskType();
 
-    internal bool IsList => IsList(this.ReturnType);
+    internal bool IsList => this.ReturnType.IsList();
 
     internal bool IsEnumerable => IsEnumerable(this.ReturnType);
 
@@ -95,6 +103,19 @@ internal MethodGenerationContext(ClassGenerationContext classGenerationContext,
         return null;
     }
 
+    private static IParameterSymbol? GetOutputResultsetParameter(IMethodSymbol methodSymbol)
+    {
+        foreach (var parameterSymbol in methodSymbol.Parameters)
+        {
+            if (parameterSymbol.Type.IsList() && (parameterSymbol.RefKind == RefKind.Out || parameterSymbol.RefKind == RefKind.Ref))
+            {
+                return parameterSymbol;
+            }
+        }
+
+        return null;
+    }
+
     private static IParameterSymbol? GetTransactionParameter(IMethodSymbol methodSymbol)
     {
         foreach (var parameterSymbol in methodSymbol.Parameters)