From 78c6b4aa3befc0ecc8134f8cd5b5e7fa0d298295 Mon Sep 17 00:00:00 2001
From: Jonathan Ong <jonathanrichardong@gmail.com>
Date: Tue, 7 Apr 2015 23:08:18 -0700
Subject: [PATCH] never pass `undefined` as an argument

closes #8
---
 index.js      | 1 +
 test/index.js | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/index.js b/index.js
index 7632ee7..74a82a8 100644
--- a/index.js
+++ b/index.js
@@ -45,6 +45,7 @@ function addWith(obj, src, exclude) {
   var vars = detect(src).map(function (global) { return global.name; })
     .filter(function (v) {
       return exclude.indexOf(v) === -1
+        && v !== 'undefined'
     })
 
   if (vars.length === 0) return src
diff --git a/test/index.js b/test/index.js
index 6f7d47e..aaffaad 100644
--- a/test/index.js
+++ b/test/index.js
@@ -153,6 +153,15 @@ describe('addWith("obj || {}", "return this[foo]")', function () {
     assert(obj.fn(obj) === 'ding')
     done()
   })
+
+  it('does not pass `undefined` as an argument', function (done) {
+    var src = addWith('obj || {}', 'return this[foo]')
+    assert(!~src.indexOf('"undefined" in locals_for_with'))
+    assert(!~src.indexOf('locals_for_with.undefined'))
+    assert(!~src.indexOf('typeof undefined!=="undefined"?undefined:undefined'))
+    outputs.push(src)
+    done()
+  })
 })
 describe('addWith("obj", "var x = (y) => y + z; x(10);")', function () {
   it('keeps reference to this', function (done) {