allow whitelisting by var name

Useful in cases when you do not know ahead of time what
the value of the global variable leak will be.

index.js

@@ -45,10 +45,14 @@ exports.detect = function detect () {
   Object.keys(global).forEach(function (key) {
     var w = whitelist.length
       , bad = true
+      , white
 
-    while (w--) if (global[key] === whitelist[w]) {
-      bad = false;
-      break;
+    while (w--) {
+      white = whitelist[w];
+      if (global[key] === white || 'string' === typeof white && key === white) {
+        bad = false;
+        break;
+      }
     }
 
     if (bad) ret.push(key);

test/index.js

@@ -57,6 +57,14 @@ exports['detect()'] = function () {
   assert.equal("haha", gleak.detect()[0]);
 }
 
+exports['unknown values can be whitelisted by passing strings'] = function () {
+  ignoreme = 1;
+  assert.ok(~gleak.detect().indexOf('ignoreme'));
+  gleak.whitelist.push('ignoreme');
+  assert.ok(!~gleak.detect().indexOf('ignoreme'));
+  delete global.ignoreme;
+}
+
 exports['print()'] = function () {
   var write = console.error;
   var times = 0;
@@ -72,7 +80,6 @@ exports['print()'] = function () {
 }
 
 exports['test middleware'] = function (beforeExit) {
-
   var called = false;
   var req = {};
   var res = { send: function (x) { assert.equal(x, 'yes'); called = true; }};