inherit generator comments and add block hoisting - fixes #196

lib/6to5/transformation/transformers/generators/visit.js

@@ -9,6 +9,7 @@
  */
 
 var runtimeProperty = require("./util").runtimeProperty;
+var traverse        = require("../../../traverse");
 var Emitter         = require("./emit").Emitter;
 var hoist           = require("./hoist").hoist;
 var types           = require("ast-types");
@@ -156,12 +157,12 @@ var visitor = types.PathVisitor.fromMethodsObject({
         )
       ]);
 
-      if (node.comments) {
-        // Copy any comments preceding the function declaration to the
-        // variable declaration, to avoid weird formatting consequences.
-        varDecl.comments = node.comments;
-        node.comments = null;
-      }
+      // Copy any comments preceding the function declaration to the
+      // variable declaration, to avoid weird formatting consequences.
+      t.inheritsComments(varDecl, node);
+      t.removeComments(node);
+
+      varDecl._blockHoist = true;
 
       var bodyPath = pp.get("body");
       var bodyLen = bodyPath.value.length;
@@ -175,7 +176,6 @@ var visitor = types.PathVisitor.fromMethodsObject({
       }
 
       bodyPath.push(varDecl);
-
     } else {
       t.assertFunctionExpression(node);
       return t.callExpression(runtimeMarkMethod, [node]);

lib/6to5/types/index.js

@@ -250,6 +250,11 @@ t.inheritsComments = function (child, parent) {
   return child;
 };
 
+t.removeComments = function (node) {
+  delete node.leadingComments;
+  delete node.trailingComments;
+};
+
 t.inherits = function (child, parent) {
   child.loc   = parent.loc;
   child.end   = parent.end;