GetServicePath should perform a scan

chrome/test/pyautolib/pyauto.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """PyAuto: Python Interface to Chromium's Automation Proxy.
 
 PyAuto uses swig to expose Automation Proxy interfaces to Python.
 For complete documentation on the functionality available,
 run pydoc on this file.
@@ skipping 776 matching lines @@
       retry_sleep: the sleep interval (in secs) before retrying |function|.
                    Defaults to 0.25 secs.
       args: the args to pass to |function|
       expect_retval: the expected return value for |function|. This forms the
                      exit criteria. In case this is None (the default),
                      |function|'s return value is checked for truth,
                      so 'non-empty-string' should match with True
       debug: if True, displays debug info at each retry.
 
     Returns:
-      True, if returning when |function| evaluated to True
+      The return value of the calling function when |function| evaluates to
+          True.

[Nirnimesh, 2012/08/08 21:58:31]

append: (or matches expect_retval)

       False, when returning due to timeout
     """
     if timeout == -1:  # Default
       timeout = self.action_max_timeout_ms() / 1000.0
     assert callable(function), "function should be a callable"
     begin = time.time()
     debug_begin = begin
     while timeout is None or time.time() - begin <= timeout:
       retval = function(*args)
-      if (expect_retval is None and retval) or expect_retval == retval:
-        return True
+      if (expect_retval is None and retval) or \
+         (expect_retval is not None and expect_retval == retval):
+        return retval
       if debug and time.time() - debug_begin > 5:
         debug_begin += 5
         if function.func_name == (lambda: True).func_name:
           function_info = inspect.getsource(function).strip()
         else:
           function_info = '%s()' % function.func_name
         logging.debug('WaitUntil(%s:%d %s) still waiting. '
                       'Expecting %s. Last returned %s.',
                       os.path.basename(inspect.getsourcefile(function)),
                       inspect.getsourcelines(function)[1],
@@ skipping 4352 matching lines @@
 
     Returns:
       The SSID of the connected network or None if we're not connected.
     """
     service_list = self.GetNetworkInfo()
     connected_service_path = service_list.get('connected_wifi')
     if 'wifi_networks' in service_list and \
        connected_service_path in service_list['wifi_networks']:
        return service_list['wifi_networks'][connected_service_path]['name']
 
-  def GetServicePath(self, ssid):
-    """Returns the service path associated with an SSID.
+  def GetServicePath(self, ssid, encryption=None, timeout=30):
+    """Waits until the SSID is observed and returns its service path.
 
     Args:
       ssid: String defining the SSID we are searching for.
+      encryption: Encryption type of the network; either None to return the
+                  first instance of network that matches the ssid, '' for
+                  an empty network, 'PSK', 'WEP' or '8021X'.
+      timeout: Duration to wait for ssid to appear.
 
     Returns:
-      The service path or None if SSID does not exist.
+      The service path or None if SSID does not exist after timeout period.
     """
-    service_list = self.GetNetworkInfo()
-    service_list = service_list.get('wifi_networks', [])
-    for service_path, service_obj in service_list.iteritems():
-      if service_obj['name'] == ssid:
-        return service_path
-    return None
+    def _get_service_path():
+      service_list = self.GetNetworkInfo().get('wifi_networks', [])
+      for service_path, service_obj in service_list.iteritems():
+        service_encr = 'PSK' if service_obj['encryption'] in ['WPA', 'RSN'] \
+                       else service_obj['encryption']
+
+        if service_obj['name'] == ssid and \
+           (encryption == None or service_encr == encryption):
+          return service_path
+      self.NetworkScan()
+      return None
+
+    service_path = self.WaitUntil(_get_service_path, timeout=timeout,
+                                  retry_sleep=1)
+    return service_path or None
 
   def NetworkScan(self):
     """Causes ChromeOS to scan for available wifi networks.
 
     Blocks until scanning is complete.
 
     Returns:
       The new list of networks obtained from GetNetworkInfo().
 
     Raises:
@@ skipping 1453 matching lines @@
     successful = result.wasSuccessful()
     if not successful:
       pyauto_tests_file = os.path.join(self.TestsDir(), self._tests_filename)
       print >>sys.stderr, 'Tests can be disabled by editing %s. ' \
                           'Ref: %s' % (pyauto_tests_file, _PYAUTO_DOC_URL)
     sys.exit(not successful)
 
 
 if __name__ == '__main__':
   Main()