Support custom parameter callbacks in QueryMultiple

Dapper/SqlMapper.cs

@@ -1157,7 +1157,7 @@ private static GridReader QueryMultipleImpl(this IDbConnection cnn, ref CommandD
                 cmd = command.SetupCommand(cnn, info.ParamReader);
                 reader = ExecuteReaderWithFlagsFallback(cmd, wasClosed, CommandBehavior.SequentialAccess);
 
-                var result = new GridReader(cmd, reader, identity, command.Parameters as DynamicParameters, command.AddToCache);
+                var result = new GridReader(cmd, reader, identity, command.Parameters as IParameterCallbacks, command.AddToCache);
                 cmd = null; // now owned by result
                 wasClosed = false; // *if* the connection was closed and we got this far, then we now have a reader
                 // with the CloseConnection flag, so the reader will deal with the connection; we

Directory.Packages.props

@@ -38,6 +38,7 @@
     <PackageVersion Include="RepoDb.SqlServer" Version="1.13.1" />
     <PackageVersion Include="ServiceStack.OrmLite.SqlServer" Version="10.0.6" />
     <PackageVersion Include="Snowflake.Data" Version="5.5.0" />
+    <PackageVersion Include="pengdows.crud.fakeDb" Version="2.0.5" />
     <PackageVersion Include="SqlMarshal" Version="0.5.0" />
     <PackageVersion Include="SubSonic" Version="3.0.0.4" />
     <PackageVersion Include="Susanoo.SqlServer" Version="1.2.4.2" />

tests/Dapper.Tests/Dapper.Tests.csproj

@@ -32,6 +32,7 @@
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' != 'net481'">
+    <PackageReference Include="pengdows.crud.fakeDb" />
     <PackageReference Include="Npgsql" />
     <PackageReference Include="Snowflake.Data" />
   </ItemGroup>

tests/Dapper.Tests/FakeDbTests.Issue2179.cs

@@ -0,0 +1,37 @@
+#if !NET481
+using System.Collections.Generic;
+using System.Data;
+using System.Linq;
+using pengdows.crud.fakeDb;
+using Xunit;
+
+namespace Dapper.Tests;
+
+public sealed class FakeDbIssue2179Tests
+{
+    [Fact]
+    public void QueryMultipleInvokesCustomParameterCallbacks()
+    {
+        using var connection = new fakeDbConnection(new FakeDataStore());
+        connection.EnqueueReaderResult(new[] { new Dictionary<string, object?> { ["Value"] = 1 } });
+        connection.Open();
+        var parameters = new CallbackParameters();
+
+        using (var grid = connection.QueryMultiple("select 1", parameters))
+        {
+            Assert.Equal(1, grid.Read<int>().Single());
+        }
+
+        Assert.Equal(1, parameters.CompletedCalls);
+    }
+
+    private sealed class CallbackParameters : SqlMapper.IParameterCallbacks
+    {
+        public int CompletedCalls { get; private set; }
+
+        void SqlMapper.IDynamicParameters.AddParameters(IDbCommand command, SqlMapper.Identity identity) { }
+
+        void SqlMapper.IParameterCallbacks.OnCompleted() => CompletedCalls++;
+    }
+}
+#endif