fix native type constructor spread - closes #373

lib/6to5/file.js

@@ -29,6 +29,7 @@ File.helpers = [
   "object-without-properties",
   "has-own",
   "slice",
+  "bind",
   "define-property",
   "async-to-generator",
   "interop-require-wildcard",

lib/6to5/transformation/templates/bind.js

@@ -0,0 +1 @@
+Function.prototype.bind

lib/6to5/transformation/transformers/es6-spread.js

@@ -1,4 +1,5 @@
 var t = require("../../types");
+var _ = require("lodash");
 
 var getSpreadLiteral = function (spread, file) {
   return file.toArray(spread.argument);
@@ -98,7 +99,14 @@ exports.NewExpression = function (node, parent, file) {
   var args = node.arguments;
   if (!hasSpread(args)) return;
 
+  var nativeType = t.isIdentifier(node.callee) && _.contains(t.NATIVE_TYPES_NAMES, node.callee.name);
+
   var nodes = build(args, file);
+
+  if (nativeType) {
+    nodes.unshift(t.arrayExpression([t.literal(null)]));
+  }
+
   var first = nodes.shift();
 
   if (nodes.length) {
@@ -107,5 +115,15 @@ exports.NewExpression = function (node, parent, file) {
     args = first;
   }
 
-  return t.callExpression(file.addHelper("apply-constructor"), [node.callee, args]);
+  if (nativeType) {
+    return t.newExpression(
+      t.callExpression(
+        t.memberExpression(file.addHelper("bind"), t.identifier("apply")),
+        [node.callee, args]
+      ),
+      []
+    );
+  } else {
+    return t.callExpression(file.addHelper("apply-constructor"), [node.callee, args]);
+  }
 };