For DefaultValue: HintString (not HintNumber) if object is a Date

date_test.go

@@ -122,3 +122,13 @@ func TestDate_setYear(t *testing.T) {
 	test(`new Date(12564504e5).setYear(1996)`, "846223200000")
 	test(`new Date(12564504e5).setYear(2000)`, "972453600000")
 }
+
+func TestDateDefaultValue(t *testing.T) {
+	Terst(t)
+
+	test := runTest()
+	test(`
+        var date = new Date();
+        date + 0 === date.toString() + "0";
+    `, "true")
+}

object.go

@@ -161,7 +161,12 @@ const (
 // 8.12.8
 func (self *_object) DefaultValue(hint _defaultValueHint) Value {
 	if hint == defaultValueNoHint {
-		hint = defaultValueHintNumber
+		if self._Date != nil {
+			// Date exception
+			hint = defaultValueHintString
+		} else {
+			hint = defaultValueHintNumber
+		}
 	}
 	methodSequence := []string{"valueOf", "toString"}
 	if hint == defaultValueHintString {