Add retry feature for push-to-trunk script.

tools/push-to-trunk/test_scripts.py

 #!/usr/bin/env python
 # Copyright 2013 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
@@ skipping 198 matching lines @@
     # Compare expected and actual arguments.
     for (expected_arg, actual_arg) in zip(expected_call, args):
       if expected_arg != actual_arg:
         raise Exception("Expected: %s - Actual: %s"
                         % (expected_arg, actual_arg))
 
     # The expectation list contains a mandatory return value and an optional
     # callback for checking the context at the time of the call.
     if len(expected_call) == len(args) + 2:
       expected_call[len(args) + 1]()
-    return expected_call[len(args)]
+    return_value = expected_call[len(args)]
+
+    # If the return value is an exception, raise it instead of returning.
+    if isinstance(return_value, Exception):
+      raise return_value
+    return return_value
 
   def AssertFinished(self):
     if self._index < len(self._recipe) -1:
       raise Exception("Called %s too seldom: %d vs. %d"
                       % (self._name, self._index, len(self._recipe)))
 
 
 class ScriptTest(unittest.TestCase):
   def MakeEmptyTempFile(self):
     handle, name = tempfile.mkstemp()
@@ skipping 32 matching lines @@
 
   def Command(self, cmd, args="", prefix="", pipe=True):
     return ScriptTest.MOCKS[cmd](self, cmd, args)
 
   def ReadLine(self):
     return self._rl_mock.Call()
 
   def ReadURL(self, url):
     return self._url_mock.Call(url)
 
+  def Sleep(self, seconds):
+    pass
+
   def ExpectGit(self, *args):
     """Convenience wrapper."""
     self._git_mock.Expect(*args)
 
   def ExpectReadline(self, *args):
     """Convenience wrapper."""
     self._rl_mock.Expect(*args)
 
   def ExpectReadURL(self, *args):
     """Convenience wrapper."""
@@ skipping 385 matching lines @@
   def testPushToTrunkForced(self):
     self._PushToTrunk(force=True)
 
   def testAutoRoll(self):
     TEST_CONFIG[DOT_GIT_LOCATION] = self.MakeEmptyTempFile()
 
     # TODO(machenbach): Get rid of the editor check in automatic mode.
     os.environ["EDITOR"] = "vi"
 
     self.ExpectReadURL([
+      ["https://v8-status.appspot.com/lkgr", Exception("Network problem")],
       ["https://v8-status.appspot.com/lkgr", "100"],
     ])
 
     self.ExpectGit([
       ["status -s -uno", ""],
       ["status -s -b -uno", "## some_branch\n"],
       ["svn fetch", ""],
       ["svn log -1 --oneline", "r101 | Text"],
     ])
 
@@ skipping 25 matching lines @@
 
 Review URL: https://codereview.chromium.org/83173002
 
 ------------------------------------------------------------------------""")
     self.assertEquals(
 """Prepare push to trunk.  Now working on version 3.23.11.
 
 R=danno@chromium.org
 
 Committed: https://code.google.com/p/v8/source/detail?r=17997""", body)