From d8c30c209ea88ad9678667580503537da4f8dbf4 Mon Sep 17 00:00:00 2001
From: Jed Fox <git@twopointzero.us>
Date: Fri, 16 Jun 2017 06:08:31 -0400
Subject: [PATCH] Should fix #576

People were calling `"foo".toString() or ["foo", "bar"].toString()`, which returned the real JS string `"[object Object]"`, the stringified version of the replacements object.
---
 packages/babel-plugin-minify-constant-folding/src/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel-plugin-minify-constant-folding/src/index.js b/packages/babel-plugin-minify-constant-folding/src/index.js
index 782d76be2..9f09489f2 100644
--- a/packages/babel-plugin-minify-constant-folding/src/index.js
+++ b/packages/babel-plugin-minify-constant-folding/src/index.js
@@ -22,7 +22,7 @@ function swap(path, member, handlers, ...args) {
   const key = getName(member);
   if (key === undefined) return;
   let handler = handlers[key];
-  if (typeof handler !== "function") {
+  if (typeof handler !== "function" || !Object.hasOwnProperty.call(handlers, key)) {
     if (typeof handlers[FALLBACK_HANDLER] === "function") {
       handler = handlers[FALLBACK_HANDLER].bind(member.object, key);
     } else {