[Android] Add a check in sharder for an empty test list.

build/android/pylib/base/shard_unittest.py

 # 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.
 
 """Unittests for shard.py."""
 
 import os
 import sys
 import unittest
 
@@ skipping 65 matching lines @@
     raise TestException
 
 
 class TestFunctions(unittest.TestCase):
   """Tests for shard._RunTestsFromQueue."""
   @staticmethod
   def _RunTests(mock_runner, tests):
     results = []
     tests = shard._TestCollection([shard._Test(t) for t in tests])
     shard._RunTestsFromQueue(mock_runner, tests, results,
-                             watchdog_timer.WatchdogTimer(None))
+                             watchdog_timer.WatchdogTimer(None), 2)
     run_results = base_test_result.TestRunResults()
     for r in results:
       run_results.AddTestRunResults(r)
     return run_results
 
   def testRunTestsFromQueue(self):
     results = TestFunctions._RunTests(MockRunner(), ['a', 'b'])
     self.assertEqual(len(results.GetPass()), 2)
     self.assertEqual(len(results.GetNotPass()), 0)
 
@@ skipping 29 matching lines @@
     runners = shard._CreateRunners(MockRunner, ['0', '1'])
     for runner in runners:
       self.assertEqual(runner.setups, 1)
     self.assertEqual(set([r.device for r in runners]),
                      set(['0', '1']))
     self.assertEqual(set([r.shard_index for r in runners]),
                      set([0, 1]))
 
   def testRun(self):
     runners = [MockRunner('0'), MockRunner('1')]
-    results = shard._RunAllTests(runners, self.tests)
+    results = shard._RunAllTests(runners, self.tests, 0)
     self.assertEqual(len(results.GetPass()), len(self.tests))
 
   def testTearDown(self):
     runners = [MockRunner('0'), MockRunner('1')]
     shard._TearDownRunners(runners)
     for runner in runners:
       self.assertEqual(runner.teardowns, 1)
 
   def testRetry(self):
     runners = shard._CreateRunners(MockRunnerFail, ['0', '1'])
-    results = shard._RunAllTests(runners, self.tests)
+    results = shard._RunAllTests(runners, self.tests, 0)
     self.assertEqual(len(results.GetFail()), len(self.tests))
 
   def testReraise(self):
     runners = shard._CreateRunners(MockRunnerException, ['0', '1'])
     with self.assertRaises(TestException):
-      shard._RunAllTests(runners, self.tests)
+      shard._RunAllTests(runners, self.tests, 0)
 
 
 class TestShard(unittest.TestCase):
   """Tests for shard.Shard."""
   @staticmethod
   def _RunShard(runner_factory):
     return shard.ShardAndRunTests(runner_factory, ['0', '1'], ['a', 'b', 'c'])
 
   def testShard(self):
     results = TestShard._RunShard(MockRunner)
     self.assertEqual(len(results.GetPass()), 3)
 
   def testFailing(self):
     results = TestShard._RunShard(MockRunnerFail)
     self.assertEqual(len(results.GetPass()), 0)
     self.assertEqual(len(results.GetFail()), 3)
 
+  def testNoTests(self):
+    results = shard.ShardAndRunTests(MockRunner, ['0', '1'], [])
+    self.assertEqual(len(results.GetAll()), 0)
+
 
 if __name__ == '__main__':
   unittest.main()