From 33e84a856e56f874b737b79f27390d55e5644f6f Mon Sep 17 00:00:00 2001
From: Devon Govett <devongovett@gmail.com>
Date: Sat, 19 May 2018 17:25:21 -0700
Subject: [PATCH] Add missing scopes when adding reference to scope tracker

Fixes "Cannot read property 'add' of undefined" error. #792 #556
---
 packages/babel-plugin-minify-mangle-names/src/scope-tracker.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/babel-plugin-minify-mangle-names/src/scope-tracker.js b/packages/babel-plugin-minify-mangle-names/src/scope-tracker.js
index 983098a5b..a37e7ced0 100644
--- a/packages/babel-plugin-minify-mangle-names/src/scope-tracker.js
+++ b/packages/babel-plugin-minify-mangle-names/src/scope-tracker.js
@@ -39,6 +39,7 @@ module.exports = class ScopeTracker {
   addReference(scope, binding, name) {
     let parent = scope;
     do {
+      this.addScope(parent);
       this.references.get(parent).add(name);
       if (!binding) {
         throw new Error(