Merge pull request #14685 from hughbe/binary-dynamic-test

Add regression test for DynamicExpression in BinaryOperationBinder

1 files changed, 33 insertions, 0 deletions

diff --git a/src/System.Linq.Expressions/tests/Dynamic/BinaryOperationTests.cs b/src/System.Linq.Expressions/tests/Dynamic/BinaryOperationTests.cs
index e71f3ab41c..9fb4490e5d 100644
--- a/src/System.Linq.Expressions/tests/Dynamic/BinaryOperationTests.cs
+++ b/src/System.Linq.Expressions/tests/Dynamic/BinaryOperationTests.cs
@@ -5,6 +5,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Linq.Expressions;
+using System.Linq.Expressions.Tests;
 using Microsoft.CSharp.RuntimeBinder;
 using Xunit;
 
@@ -698,5 +699,37 @@ namespace System.Dynamic.Tests
             dY = 49;
             Assert.Throws<RuntimeBinderException>(() => dX && dY);
         }
+
+        [Theory]
+        [ClassData(typeof(CompilationTypes))]
+        public void BinaryCallSiteBinder_DynamicExpression(bool useInterpreter)
+        {
+            DynamicExpression expression = DynamicExpression.Dynamic(
+                new BinaryCallSiteBinder(),
+                typeof(object),
+                Expression.Constant(40, typeof(object)),
+                Expression.Constant(2, typeof(object)));
+            Func<object> func = Expression.Lambda<Func<object>>(expression).Compile(useInterpreter);
+            Assert.Equal("42", func().ToString());
+        }
+
+        private class BinaryCallSiteBinder : BinaryOperationBinder
+        {
+            public BinaryCallSiteBinder() : base(ExpressionType.Add) {}
+
+            public override DynamicMetaObject FallbackBinaryOperation(DynamicMetaObject target, DynamicMetaObject arg, DynamicMetaObject errorSuggestion)
+            {
+                return new DynamicMetaObject(
+                    Expression.Convert(
+                    Expression.Add(
+                        Expression.Convert(target.Expression, typeof(int)),
+                        Expression.Convert(arg.Expression, typeof(int))
+                    ), typeof(object)),
+
+                    BindingRestrictions.GetTypeRestriction(target.Expression, typeof(int)).Merge(
+                        BindingRestrictions.GetTypeRestriction(arg.Expression, typeof(int))
+                    ));
+            }
+        }
     }
 }