test: don't compute knownGlobals lazily

Conditional globals like 'gc' should only be recognized when --expose_gc
is set.  The global.gc feature check works only when done eagerly, else
it lets through a leaked variable called 'gc'.

test/common.js

@@ -89,12 +89,6 @@ exports.spawnPwd = function(options) {
   }
 };
 
-
-// Turn this off if the test should not check for global leaks.
-exports.globalCheck = true;
-
-process.on('exit', function() {
-  if (!exports.globalCheck) return;
 var knownGlobals = [setTimeout,
                     setInterval,
                     setImmediate,
@@ -121,6 +115,7 @@ process.on('exit', function() {
   knownGlobals.push(DTRACE_NET_SOCKET_READ);
   knownGlobals.push(DTRACE_NET_SOCKET_WRITE);
 }
+
 if (global.COUNTER_NET_SERVER_CONNECTION) {
   knownGlobals.push(COUNTER_NET_SERVER_CONNECTION);
   knownGlobals.push(COUNTER_NET_SERVER_CONNECTION_CLOSE);
@@ -144,21 +139,27 @@ process.on('exit', function() {
   knownGlobals.push(DataView);
 }
 
-  for (var x in global) {
-    var found = false;
+function leakedGlobals() {
+  var leaked = [];
 
-    for (var y in knownGlobals) {
-      if (global[x] === knownGlobals[y]) {
-        found = true;
-        break;
-      }
-    }
+  for (var val in global)
+    if (-1 === knownGlobals.indexOf(global[val]))
+      leaked.push(val);
 
-    if (!found) {
-      console.error('Unknown global: %s', x);
+  return leaked;
+};
+exports.leakedGlobals = leakedGlobals;
+
+// Turn this off if the test should not check for global leaks.
+exports.globalCheck = true;
+
+process.on('exit', function() {
+  if (!exports.globalCheck) return;
+  var leaked = leakedGlobals();
+  if (leaked.length > 0) {
+    console.error('Unknown globals: %s', leaked);
     assert.ok(false, 'Unknown global found');
   }
-  }
 });
 
 

test/simple/test-common.js

@@ -0,0 +1,27 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+var common = require('../common');
+var assert = require('assert');
+
+common.globalCheck = false;
+global.gc = 42;  // Not a valid global unless --expose_gc is set.
+assert.deepEqual(common.leakedGlobals(), ['gc']);