Handle Invoke being called via a method group

src/LinqKit.Core/ExpressionExpander.cs

@@ -108,6 +108,28 @@ protected bool GetExpandLambda(MemberInfo memberInfo, out LambdaExpression expan
             return false;
         }
 
+        protected override Expression VisitUnary(UnaryExpression node)
+        {
+            // When Invoke is called via a method group (e.g. x => x.Any(filter.Invoke)), it will be wrapped in Convert(CreateDelegate(...)).
+            if (
+                node.NodeType == ExpressionType.Convert
+                && node.Operand is MethodCallExpression methodCall
+                && methodCall.Method.Name == "CreateDelegate"
+                && methodCall.Method.DeclaringType == typeof(MethodInfo)
+                && methodCall.Object is ConstantExpression methodInfoConst
+                && methodCall.Arguments.Count == 2
+                && methodInfoConst.Value is MethodInfo methodInfo
+                && methodInfo.Name == nameof(ExtensionsCore.Invoke)
+                && methodInfo.DeclaringType == typeof(ExtensionsCore))
+            {
+                var target = methodCall.Arguments[1];
+
+                return Visit(target);
+            }
+
+            return base.VisitUnary(node);
+        }
+
         protected override Expression VisitMethodCall(MethodCallExpression m)
         {
             if (m.Method.Name == nameof(ExtensionsCore.Invoke) && m.Method.DeclaringType == typeof(ExtensionsCore))

tests/LinqKit.Tests.Net452/ExpressionCombinerTests.cs

@@ -227,6 +227,15 @@ public void ExpandProcessesArguments()
                 nestedExpression.Expand().Expand().ToString());
         }
 
+        [Fact]
+        public void ExpandProcessesInvokeAsMethodGroup()
+        {
+            Expression<Func<int, bool>> filter = p => p > 1000;
+            Expression<Func<int[], bool>> anyMeetsFilter = x => x.Any(filter.Invoke);
+
+            Assert.Equal("x => x.Any(p => (p > 1000))", anyMeetsFilter.Expand().ToString());
+        }
+
         private string ConstExpressionString<TResult>(Expression<Func<TResult>> expr)
         {
             return expr.ToString().Substring(6);