WebDriverWait and SauceLabs

If you've used the WebDriverWait class with SauceLabs, you may have noticed that it actually will run beyond the designated timeout period. I first noticed this issue when seeing that this function took 40 minutes to complete with a 20 second implicit wait time and a 60 second timeout w/ .5 poll frequency! (60 / .5 = 120 loops * 20 seconds/implicit wait = 2400 seconds total)

The problem appears to be that WebDriverWait attempts to run self._timeout / self._poll times before returning a Timeout Exception:

for _ in xrange(max(1, int(self._timeout/self._poll))):

Since this code could wait until an ElementNotFound exception is found (and if the implicit wait time is increased), then the total time this routine takes is a function of the total # of loops * poll frequency * the implicit wait time.

The correct patch appears to be recording the start time and looping until the maximum timeout period has been exceeded:

--- a/selenium/webdriver/support/wait.py
+++ b/selenium/webdriver/support/wait.py
@@ -24,7 +24,7 @@ class WebDriverWait(object):
 
     def __init__(self, driver, timeout, poll_frequency=POLL_FREQUENCY):
         """Constructor, takes a WebDriver instance and timeout in seconds.
-           
+
            :Args:
             - driver - Instance of WebDriver (Ie, Firefox, Chrome or Remote)
             - timeout - Number of seconds before timing out
@@ -43,7 +43,8 @@ class WebDriverWait(object):
     def until(self, method):
         """Calls the method provided with the driver as an argument until the \
         return value is not Falsy."""
-        for _ in xrange(max(1, int(self._timeout/self._poll))):
+        end_time = time.time() + self._timeout
+        while(time.time() < end_time):
             try:
                 value = method(self._driver)
                 if value:

The bug report is filed here:

http://code.google.com/p/selenium/issues/detail?id=2939