From 3f144e6e74f19fd345d5948baab0883bce58e0cf Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Sat, 28 Mar 2015 04:34:05 +1100
Subject: [PATCH] ensure that nodes are only traversed once per context

---
 src/babel/traversal/context.js    | 10 ++++++++--
 src/babel/traversal/path/index.js | 13 +++++--------
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/babel/traversal/context.js b/src/babel/traversal/context.js
index 1642bc8b6f..1e9dd23183 100644
--- a/src/babel/traversal/context.js
+++ b/src/babel/traversal/context.js
@@ -18,9 +18,10 @@ export default class TraversalContext {
     // nothing to traverse!
     if (nodes.length === 0) return false;
 
+    var visited = [];
+
     var queue = this.queue = [];
     var stop  = false;
-    var done  = [];
 
     // build up initial queue
     for (let i = 0; i < nodes.length; i++) {
@@ -29,7 +30,12 @@ export default class TraversalContext {
 
     // visit the queue
     for (let i = 0; i < queue.length; i++) {
-      if (queue[i].visit()) {
+      var path = queue[i];
+      if (visited.indexOf(path.node) >= 0) continue;
+
+      visited.push(path.node);
+
+      if (path.visit()) {
         stop = true;
         break;
       }
diff --git a/src/babel/traversal/path/index.js b/src/babel/traversal/path/index.js
index d6a164c01c..467c612875 100644
--- a/src/babel/traversal/path/index.js
+++ b/src/babel/traversal/path/index.js
@@ -97,6 +97,7 @@ export default class TraversalPath {
 
   _containerInsertAfter(nodes) {
     this.updateSiblingKeys(this.key + 1, nodes.length);
+
     for (var i = 0; i < nodes.length; i++) {
       var to = this.key + 1 + i;
       this.container.splice(to, 0, nodes[i]);
@@ -222,7 +223,7 @@ export default class TraversalPath {
   replaceInline(nodes) {
     if (Array.isArray(nodes)) {
       if (Array.isArray(this.container)) {
-        this._verifyNodeList("replaceInline", nodes);
+        this._verifyNodeList(nodes);
         this._containerInsertAfter(nodes);
         return this.remove();
       } else {
@@ -233,19 +234,15 @@ export default class TraversalPath {
     }
   }
 
-  _verifyNodeList(key, nodes) {
-    if (nodes.indexOf(this.node) >= 0) {
-      // todo: possibly check for inclusion of current node and yell at the user as it's an anti-pattern
-    }
-
+  _verifyNodeList(nodes) {
     for (var i = 0; i < nodes.length; i++) {
       var node = nodes[i];
-      if (!node) throw new Error(`Falsy node passed to \`path.${key}()\` with the index of ${i}`);
+      if (!node) throw new Error(`Node list has falsy node with the index of ${i}`);
     }
   }
 
   replaceWithMultiple(nodes: Array<Object>) {
-    this._verifyNodeList("replaceWithMultiple", nodes);
+    this._verifyNodeList(nodes);
     t.inheritsComments(nodes[0], this.node);
     this.container[this.key] = null;
     this.insertAfter(nodes);