Bug 665410 - waitFor callback has to return a boolean value. r=ctalbert

mozmill/mozmill/extension/resource/stdlib/utils.js

@@ -404,7 +404,13 @@ function waitFor(callback, message, timeout, interval, thisObject) {
   var thread = Cc["@mozilla.org/thread-manager;1"]
                .getService().currentThread;
 
-  while ((self.result != true) && (self.counter < timeout))  {
+  while (true) {
+    if (typeof(self.result) !== 'boolean')
+      throw TypeError("waitFor() callback has to return a boolean value.");
+
+    if (self.result === true || self.counter >= timeout)
+      break;
+
     thread.processNextEvent(true);
   }
 

mutt/mutt/tests/js/test_waitFor.js

@@ -0,0 +1,29 @@
+var setupModule = function () {
+  controller = mozmill.getBrowserController();
+}
+
+var testWaitForCallback = function () {
+  expect.doesNotThrow(function () {
+    controller.waitFor(function () {
+      return true;
+    });
+  }, "TypeError", "Return type 'boolean' in callback is supported.");
+
+  expect.throws(function () {
+    controller.waitFor(function () {
+      return 4;
+    });
+  }, "TypeError", "Return type 'number' in callback is not supported.");
+
+  expect.throws(function () {
+    controller.waitFor(function () {
+      return "true";
+    });
+  }, "TypeError", "Return type 'string' in callback is not supported.");
+
+  expect.throws(function () {
+    controller.waitFor(function () {
+      return new Object();
+    });
+  }, "TypeError", "Return type 'Object' in callback is not supported.");
+}