fix automatic closure on private declarations - fixes #335

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

@@ -8,16 +8,24 @@ exports.ClassDeclaration = function (node, parent, file, scope) {
     closure = false;
   }
 
-  var newNode = new Class(node, file, scope, closure).run();
-  if (closure) {
-    // declaration in an expression context...
-    // export default class Foo {}
-    scope.push({
-      kind: "var",
-      key: node.id.key,
-      id: node.id
-    });
-    return t.assignmentExpression("=", node.id, newNode);
+  var factory = new Class(node, file, scope, closure);
+  var newNode = factory.run();
+  if (factory.closure) {
+    if (closure) {
+      // declaration in an expression context...
+      // export default class Foo {}
+      scope.push({
+        kind: "var",
+        key: node.id.key,
+        id: node.id
+      });
+      return t.assignmentExpression("=", node.id, newNode);
+    } else {
+      // likely has a PrivateDeclaration etc
+      return t.variableDeclaration("let", [
+        t.variableDeclarator(node.id, newNode)
+      ]);
+    }
   } else {
     return newNode;
   }