Adds saner behavior for git try -t foo to not fail in a inexplicable way. Enforces that each builde…

tests/presubmit_unittest.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.
 
 """Unit tests for presubmit_support.py and presubmit_canned_checks.py."""
 
 # pylint: disable=E1101,E1103
 
 import logging
@@ skipping 774 matching lines @@
                      presubmit.DoGetTrySlaves(change, [filename],
                                               self.fake_root_dir,
                                               None, None, False, output))
     output = StringIO.StringIO()
     self.assertEqual(['win', 'linux'],
                      presubmit.DoGetTrySlaves(change,
                                               [filename, filename_linux],
                                               self.fake_root_dir, None, None,
                                               False, output))
 
+  def testGetTrySlavesExecuter_ok(self):
+    script_text = (
+        'def GetPreferredTrySlaves():\n'
+        '  return ["foo", "bar"]\n')
+    results = presubmit.GetTrySlavesExecuter.ExecPresubmitScript(
+        script_text, 'path', 'project', None)
+    self.assertEquals(['foo', 'bar'], results)
+
+  def testGetTrySlavesExecuter_comma(self):
+    script_text = (
+        'def GetPreferredTrySlaves():\n'
+        '  return ["foo,bar"]\n')
+    try:
+      presubmit.GetTrySlavesExecuter.ExecPresubmitScript(
+          script_text, 'path', 'project', None)
+      self.fail()
+    except presubmit.PresubmitFailure:
+      pass
+
   def testMainUnversioned(self):
     # OptParser calls presubmit.os.path.exists and is a pain when mocked.
     self.UnMock(presubmit.os.path, 'exists')
     self.mox.StubOutWithMock(presubmit, 'DoPresubmitChecks')
     self.mox.StubOutWithMock(presubmit, 'ParseFiles')
     presubmit.scm.determine_scm(self.fake_root_dir).AndReturn(None)
     presubmit.ParseFiles(['random_file.txt'], None
         ).AndReturn([('M', 'random_file.txt')])
     output = self.mox.CreateMock(presubmit.PresubmitOutput)
     output.should_continue().AndReturn(False)
@@ skipping 1560 matching lines @@
         owners_check=False)
     self.assertEqual(1, len(results))
     self.assertEqual(
         'Found line ending with white spaces in:', results[0]._message)
     self.checkstdout('')
 
 
 if __name__ == '__main__':
   import unittest
   unittest.main()