Handle implicit convert expression in LINQ update with anonymous type

src/NHibernate.Test.VisualBasic/Issues/GH3716/Entity.vb

@@ -0,0 +1,7 @@
+Namespace Issues.GH3716
+ Public Class Entity
+ Public Overridable Property Id As Guid
+
+ Public Overridable Property Date1 As Date?
+ End Class
+End Namespace

src/NHibernate.Test.VisualBasic/Issues/GH3716/Fixture.vb

@@ -0,0 +1,58 @@
+Imports NHibernate.Linq
+Imports NUnit.Framework
+
+Namespace Issues.GH3716
+ <TestFixture>
+ Public Class Fixture
+ Inherits IssueTestCase
+
+ Protected Overrides Sub OnSetUp()
+
+ Using session As ISession = OpenSession()
+
+ Using transaction As ITransaction = session.BeginTransaction()
+
+ Dim e1 = New Entity
+ e1.Date1 = New Date(2017, 12, 3)
+ session.Save(e1)
+
+ Dim e2 = New Entity
+ e2.Date1 = New Date(2017, 12, 1)
+ session.Save(e2)
+
+ Dim e3 = New Entity
+ session.Save(e3)
+
+ session.Flush()
+ transaction.Commit()
+
+ End Using
+
+ End Using
+ End Sub
+
+ Protected Overrides Sub OnTearDown()
+
+ Using session As ISession = OpenSession()
+
+ Using transaction As ITransaction = session.BeginTransaction()
+
+ session.Delete("from System.Object")
+
+ session.Flush()
+ transaction.Commit()
+
+ End Using
+
+ End Using
+ End Sub
+
+ <Test>
+ Public Sub ShouldBeAbleToUpdateWithAnonymousType()
+
+ Using session As ISession = OpenSession()
+ session.Query(Of Entity).Update(Function(x) New With {.Date1 = Date.Today})
+ End Using
+ End Sub
+ End Class
+End Namespace

src/NHibernate.Test.VisualBasic/Issues/GH3716/Issues.GH3716.Mappings.hbm.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="NHibernate.Test.VisualBasic" namespace="NHibernate.Test.VisualBasic.Issues.GH3716">
+
+<class name="Entity">
+<id name="Id">
+<generator class="guid.comb"/>
+</id>
+<property name="Date1" />
+</class>
+
+</hibernate-mapping>

src/NHibernate.Test.VisualBasic/NHibernate.Test.VisualBasic.vbproj

@@ -26,7 +26,6 @@
  </ItemGroup>
  <ItemGroup>
  <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
- <PackageReference Include="Microsoft.VisualBasic" Version="10.3.0" />
  <PackageReference Include="NUnit" Version="3.14.0" />
  <PackageReference Include="NUnit3TestAdapter" Version="4.6.0" />
  </ItemGroup>

src/NHibernate/Linq/DmlExpressionRewriter.cs

@@ -25,10 +25,10 @@ void AddSettersFromBindings(IEnumerable<MemberBinding> bindings, string path)
 switch (node.BindingType)
 {
 case MemberBindingType.Assignment:
-AddSettersFromAssignment((MemberAssignment)node, subPath);
+AddSettersFromAssignment((MemberAssignment) node, subPath);
 break;
 case MemberBindingType.MemberBinding:
-AddSettersFromBindings(((MemberMemberBinding)node).Bindings, subPath);
+AddSettersFromBindings(((MemberMemberBinding) node).Bindings, subPath);
 break;
 default:
 throw new InvalidOperationException($"{node.BindingType} is not supported");
@@ -53,10 +53,10 @@ void AddSettersFromAnonymousConstructor(NewExpression newExpression, string path
 switch (argument.NodeType)
 {
 case ExpressionType.New:
-AddSettersFromAnonymousConstructor((NewExpression)argument, subPath);
+AddSettersFromAnonymousConstructor((NewExpression) argument, subPath);
 break;
 case ExpressionType.MemberInit:
-AddSettersFromBindings(((MemberInitExpression)argument).Bindings, subPath);
+AddSettersFromBindings(((MemberInitExpression) argument).Bindings, subPath);
 break;
 default:
 _assignments.Add(subPath.Substring(1), Expression.Lambda(argument, _parameters));
@@ -121,15 +121,25 @@ public static Expression PrepareExpressionFromAnonymous<TSource>(Expression sour
 if (expression == null)
 throw new ArgumentNullException(nameof(expression));
 
-// Anonymous initializations are not implemented as member initialization but as plain constructor call.
-var newExpression = expression.Body as NewExpression ??
+// Anonymous initializations are not implemented as member initialization but as plain constructor call, potentially wrapped in a Convert expression
+var newExpression = UnwrapConvertExpression(expression.Body) as NewExpression ??
 throw new ArgumentException("The expression must be an anonymous initialization, e.g. x => new { Name = x.Name, Age = x.Age + 5 }");
 
 var instance = new DmlExpressionRewriter(expression.Parameters);
 instance.AddSettersFromAnonymousConstructor(newExpression, "");
 return PrepareExpression<TSource>(sourceExpression, instance._assignments);
 }
 
+private static Expression UnwrapConvertExpression(Expression expression)
+{
+if (expression is UnaryExpression ue && ue.NodeType == ExpressionType.Convert)
+{
+return ue.Operand;
+}
+
+return expression;
+}
+
 public static Expression PrepareExpression<TSource>(Expression sourceExpression, IReadOnlyDictionary<string, Expression> assignments)
 {
 var lambda = ConvertAssignmentsToBlockExpression<TSource>(assignments);