Adds test for the issue

Author: alex-kulakov

Orm/Xtensive.Orm.Tests/Issues/IssueJira0800_DtoInterfaceFieldInitializationWithinCtor.cs

@@ -0,0 +1,132 @@
+// Copyright (C) 2020 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
+
+using NUnit.Framework;
+using System;
+using System.Linq;
+using Xtensive.Orm;
+using Xtensive.Orm.Configuration;
+using Xtensive.Orm.Tests;
+using Xtensive.Orm.Tests.Issues.IssueJira0800_InterfaceImplementingDtoProblemModel;
+
+namespace Xtensive.Orm.Tests.Issues
+{
+  [TestFixture]
+  public class IssueJira0800_DtoInterfaceFieldInitializationWithinCtor : AutoBuildTest
+  {
+    protected override DomainConfiguration BuildConfiguration()
+    {
+      var config = base.BuildConfiguration();
+      config.Types.Register(typeof(Example));
+      config.UpgradeMode = DomainUpgradeMode.Recreate;
+      return config;
+    }
+
+    [Test]
+    public void FilterThroughInterfaceMethod()
+    {
+      using (var session = Domain.OpenSession())
+      using (var transaction = session.OpenTransaction()) {
+        var query = session.Query
+          .All<Example>()
+          .Select(x => new ExampleDto { EndDate = x.EndDate })
+          .ApplyFilterUsingInterface();
+        var expression = query.Expression;
+        Console.WriteLine(expression);
+        _ = query.ToArray();
+      }
+    }
+
+    [Test]
+    public void FilterThroughBaseClassMethod()
+    {
+      using (var session = Domain.OpenSession())
+      using (var transaction = session.OpenTransaction()) {
+        var query = session.Query
+          .All<Example>()
+          .Select(x => new ExampleDto { EndDate = x.EndDate })
+          .ApplyFilterUsingBaseClass();
+        var expression = query.Expression;
+        Console.WriteLine(expression);
+        _ = query.ToArray();
+      }
+    }
+
+    [Test]
+    public void FilterDirectlyWithInterface()
+    {
+      using (var session = Domain.OpenSession())
+      using (var transaction = session.OpenTransaction()) {
+        var query = session.Query
+          .All<Example>()
+          .Select(x => (IEndOwner) new ExampleDto { EndDate = x.EndDate })
+          .Where(x => x.EndDate == null);
+        var expression = query.Expression;
+        Console.WriteLine(expression);
+        _ = query.ToArray();
+      }
+    }
+
+    [Test]
+    public void FilterDirectlyWithExactType()
+    {
+      using (var session = Domain.OpenSession())
+      using (var transaction = session.OpenTransaction()) {
+        var query = session.Query
+          .All<Example>()
+          .Select(x => new ExampleDto { EndDate = x.EndDate })
+          .Where(x => x.EndDate == null);
+        var expression = query.Expression;
+        Console.WriteLine(expression);
+        _ = query.ToArray();
+      }
+    }
+  }
+}
+
+namespace Xtensive.Orm.Tests.Issues.IssueJira0800_InterfaceImplementingDtoProblemModel
+{
+  public class ExampleDto : EndOwner
+  {
+    public long Id { get; set; }
+
+    public override DateTime? EndDate { get; set; }
+  }
+
+  [HierarchyRoot]
+  public class Example : Entity
+  {
+    [Field, Key]
+    public long Id { get; set; }
+
+    [Field]
+    public DateTime? EndDate { get; set; }
+  }
+
+  public static class ContractsExtensions
+  {
+    public static IQueryable<TContractOwner> ApplyFilterUsingBaseClass<TContractOwner>(this IQueryable<TContractOwner> query)
+      where TContractOwner : EndOwner
+    {
+      return query.Where(x => x.EndDate == null);
+    }
+
+    public static IQueryable<TContractOwner> ApplyFilterUsingInterface<TContractOwner>(this IQueryable<TContractOwner> query)
+      where TContractOwner : class, IEndOwner
+    {
+      return query.Where(x => x.EndDate == null);
+    }
+  }
+
+  public abstract class EndOwner : IEndOwner
+  {
+    public abstract DateTime? EndDate { get; set; }
+  }
+
+
+  public interface IEndOwner
+  {
+    DateTime? EndDate { get; }
+  }
+}