Use ReferenceEquals to prevent infinite recursion; add regression test for the equals operator

Author: spahnke

Source/Noesis.Javascript/JavascriptFunction.cpp

@@ -75,8 +75,8 @@ System::Object^ JavascriptFunction::Call(... cli::array<System::Object^>^ args)
 
 bool JavascriptFunction::operator==(JavascriptFunction^ func1, JavascriptFunction^ func2)
 {
-    bool func1_null = func1 == nullptr,
-         func2_null = func2 == nullptr;
+    bool func1_null = ReferenceEquals(func1, nullptr),
+         func2_null = ReferenceEquals(func2, nullptr);
     if (func1_null != func2_null)
 		return false;
     if (func1_null && func2_null)

Tests/Noesis.Javascript.Tests/JavascriptFunctionTests.cs

@@ -33,6 +33,18 @@ public void GetFunctionExpressionFromJsContext()
             funcObj.Call(1, 2).Should().BeOfType<int>().Which.Should().Be(3);
         }
 
+        [TestMethod]
+        public void EqualsOperatorWorksWithFunctionObjects()
+        {
+            _context.Run("a = function(a, b) { return a + b; }");
+
+            JavascriptFunction funcObj = _context.GetParameter("a") as JavascriptFunction;
+            (funcObj == null).Should().BeFalse();
+            (funcObj != null).Should().BeTrue();
+            (null == funcObj).Should().BeFalse();
+            (null != funcObj).Should().BeTrue();
+        }
+
         [TestMethod]
         public void GetNamedFunctionFromJsContext()
         {