Don't throw when CLR indexer not found

Jint.Tests/Runtime/Domain/FloatIndexer.cs

@@ -0,0 +1,21 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Jint.Tests.Runtime.Domain
+{
+    public class FloatIndexer
+    {
+		public string this[int index]
+		{
+			get
+			{
+				return "";
+				//throw new Exception();
+			}
+		}
+
+	}
+}

Jint.Tests/Runtime/InteropTests.cs

@@ -1946,5 +1946,19 @@ public void ShouldBeAbleToPlusAssignStringProperty()
             engine.Execute("P.Name += 'c';");
             Assert.Equal("bc", p.Name);
         }
+
+        [Fact]
+        public void ShouldNotResolvetoPrimitiveSymbol()
+        {
+            var engine = new Engine(options => 
+                options.AllowClr(typeof(FloatIndexer).GetTypeInfo().Assembly));
+            var c = engine.Execute(@"
+                var domain = importNamespace('Jint.Tests.Runtime.Domain');
+                return new domain.FloatIndexer();
+            ").GetCompletionValue();
+
+            Assert.NotNull(c.ToString());
+            Assert.Equal((uint)0, c.As<ObjectInstance>().Length);
+        }
     }
 }

Jint/Runtime/Descriptors/Specialized/IndexDescriptor.cs

@@ -46,12 +46,6 @@ public IndexDescriptor(Engine engine, Type targetType, string key, object item)
                 }
             }
 
-            // throw if no indexer found
-            if (_indexer == null)
-            {
-                ExceptionHelper.ThrowInvalidOperationException("No matching indexer found.");
-            }
-
             Writable = engine.Options._IsClrWriteAllowed;
         }
 
@@ -64,6 +58,11 @@ protected internal override JsValue CustomValue
         {
             get
             {
+                if (_indexer == null)
+                {
+                    return JsValue.Undefined;
+                }
+
                 var getter = _indexer.GetGetMethod();
 
                 if (getter == null)
@@ -93,6 +92,11 @@ protected internal override JsValue CustomValue
 
             set
             {
+                if (_indexer == null)
+                {
+                    return;
+                }
+
                 var setter = _indexer.GetSetMethod();
                 if (setter == null)
                 {

Jint/Runtime/Interop/ObjectWrapper.cs

@@ -52,6 +52,11 @@ public override bool Set(JsValue property, JsValue value, JsValue receiver)
 
         public override PropertyDescriptor GetOwnProperty(JsValue property)
         {
+            if (property.IsSymbol())
+            {
+                return PropertyDescriptor.Undefined;
+            }
+
             if (TryGetProperty(property, out var x))
             {
                 return x;

Jint/Runtime/TypeConverter.cs

@@ -490,6 +490,8 @@ private static string ToStringNonString(JsValue o)
                     return Null.Text;
                 case InternalTypes.Object when o is IPrimitiveInstance p:
                     return ToString(ToPrimitive(p.PrimitiveValue, Types.String));
+                case InternalTypes.Object when o is Interop.IObjectWrapper p:
+                    return ToString(ToPrimitive(p.Target?.ToString(), Types.String));
                 default:
                     return ToString(ToPrimitive(o, Types.String));
             }