Merge pull request #240 from thejameskyle/arguments-spread

Only slice arguments when necessary - fixes #239

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

@@ -64,7 +64,12 @@ exports.CallExpression = function (node, parent, file) {
 
   node.arguments = [];
 
-  var nodes = build(args, file);
+  var nodes;
+  if (args.length === 1 && args[0].argument.name === 'arguments') {
+    nodes = [args[0].argument];
+  } else {
+    nodes = build(args, file);
+  }
   var first = nodes.shift();
 
   if (nodes.length) {

test/fixtures/transformation/es6-spread/arguments-array/actual.js

@@ -0,0 +1,9 @@
+function foo() {
+  return bar([...arguments]);
+}
+
+function bar(one, two, three) {
+  return [one, two, three];
+}
+
+foo("foo", "bar");

test/fixtures/transformation/es6-spread/arguments-array/expected.js

@@ -0,0 +1,12 @@
+"use strict";
+
+var _slice = Array.prototype.slice;
+function foo() {
+  return bar([].concat(_slice.call(arguments)));
+}
+
+function bar(one, two, three) {
+  return [one, two, three];
+}
+
+foo("foo", "bar");

test/fixtures/transformation/es6-spread/arguments-concat/actual.js

@@ -0,0 +1,9 @@
+function foo() {
+  return bar("test", ...arguments);
+}
+
+function bar(one, two, three) {
+  return [one, two, three];
+}
+
+foo("foo", "bar");

test/fixtures/transformation/es6-spread/arguments-concat/expected.js

@@ -0,0 +1,12 @@
+"use strict";
+
+var _slice = Array.prototype.slice;
+function foo() {
+  return bar.apply(null, ["test"].concat(_slice.call(arguments)));
+}
+
+function bar(one, two, three) {
+  return [one, two, three];
+}
+
+foo("foo", "bar");

test/fixtures/transformation/es6-spread/arguments/actual.js

@@ -1,5 +1,5 @@
 function foo() {
-  return bar("test", ...arguments);
+  return bar(...arguments);
 }
 
 function bar(one, two, three) {

test/fixtures/transformation/es6-spread/arguments/expected.js

@@ -1,8 +1,7 @@
 "use strict";
 
-var _slice = Array.prototype.slice;
 function foo() {
-  return bar.apply(null, ["test"].concat(_slice.call(arguments)));
+  return bar.apply(null, arguments);
 }
 
 function bar(one, two, three) {