v1.13.4

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 1.13.4
+
+ * Fix single spread element returning itself.
+
 # 1.13.3
 
  * Upgrade `acorn-6to5`.

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

@@ -48,7 +48,10 @@ exports.ArrayExpression = function (node, parent, file) {
   var nodes = build(elements, file);
   var first = nodes.shift();
 
-  if (!nodes.length) return first;
+  if (!t.isArrayExpression(first)) {
+    nodes.unshift(first);
+    first = t.arrayExpression([]);
+  }
 
   return t.callExpression(t.memberExpression(first, t.identifier("concat")), nodes);
 };

package.json

@@ -1,7 +1,7 @@
 {
   "name": "6to5",
   "description": "Turn ES6 code into readable vanilla ES5 with source maps",
-  "version": "1.13.3",
+  "version": "1.13.4",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://github.com/6to5/6to5",
   "repository": {

test/fixtures/transformation/es6-spread/array-literal-first/expected.js

@@ -4,4 +4,4 @@ var _toArray = function (arr) {
   return Array.isArray(arr) ? arr : Array.from(arr);
 };
 
-var lyrics = _toArray(parts).concat(["head", "and", "toes"]);
+var lyrics = [].concat(_toArray(parts), ["head", "and", "toes"]);

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

@@ -4,4 +4,4 @@ var _toArray = function (arr) {
   return Array.isArray(arr) ? arr : Array.from(arr);
 };
 
-_toArray(foo);
+[].concat(_toArray(foo));