add traversal node aliases to be dry

lib/6to5/file.js

@@ -84,7 +84,14 @@ File.prototype.runTransformer = function (name, transformer) {
 
   var build = function (exit) {
     return function (node, parent) {
-      var fns = transformer[node.type] || transformer.all;
+      var types = [node.type].concat(traverse.aliases[node.type] || []);
+
+      var fns = transformer.all;
+
+      _.each(types, function (type) {
+        fns = transformer[type] || fns;
+      });
+
       if (!fns) return;
 
       var fn = fns.enter || fns;

lib/6to5/transformers/default-parameters.js

@@ -1,9 +1,7 @@
 var util = require("../util");
 var _    = require("lodash");
 
-exports.ArrowFunctionExpression =
+exports.Function = function (node) {
-exports.FunctionDeclaration =
-exports.FunctionExpression = function (node) {
   if (!node.defaults.length) return;
   util.ensureBlock(node);
 

lib/6to5/transformers/destructuring.js

@@ -85,9 +85,7 @@ exports.ForOfStatement = function (node, parent, file) {
   block.body = nodes.concat(block.body);
 };
 
-exports.ArrowFunctionExpression =
+exports.Function = function (node, parent, file) {
-exports.FunctionDeclaration =
-exports.FunctionExpression = function (node, parent, file) {
   var block = node.body;
   var nodes = [];
 

lib/6to5/transformers/rest-parameters.js

@@ -1,9 +1,7 @@
 var util = require("../util");
 var b    = require("ast-types").builders;
 
-exports.ArrowFunctionExpression =
+exports.Function = function (node) {
-exports.FunctionDeclaration =
-exports.FunctionExpression = function (node) {
   if (!node.rest) return;
 
   var rest = node.rest;

lib/6to5/traverse/index.js

@@ -69,6 +69,16 @@ var traverse = module.exports = function (parent, callbacks, blacklistTypes) {
 
 traverse.FUNCTION_TYPES = ["ArrowFunctionExpression", "FunctionDeclaration", "FunctionExpression"];
 
+traverse.aliases = {
+  ArrowFunctionExpression: ["Function"],
+  FunctionDeclaration:     ["Function"],
+  FunctionExpression:      ["Function"]
+};
+
+traverse.isFunction = function (node) {
+  return _.contains(traverse.FUNCTION_TYPES, node.type);
+};
+
 traverse.Delete = {};
 
 traverse.hasType = function (tree, type, blacklistTypes) {