Modify scm.GIT.GetUpstreamBranch to behave like git-cl.

tests/trychange_unittest.py

 #!/usr/bin/python
 # Copyright (c) 2010 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 trychange.py."""
 
 # Fixes include path.
 from super_mox import mox, SuperMoxTestBase
 
 import trychange
 
 
 class TryChangeTestsBase(SuperMoxTestBase):
   """Setups and tear downs the mocks but doesn't test anything as-is."""
   def setUp(self):
     SuperMoxTestBase.setUp(self)
     self.mox.StubOutWithMock(trychange.gclient_utils, 'CheckCall')
     self.mox.StubOutWithMock(trychange.scm.GIT, 'Capture')
     self.mox.StubOutWithMock(trychange.scm.GIT, 'GenerateDiff')
     self.mox.StubOutWithMock(trychange.scm.GIT, 'GetCheckoutRoot')
+    self.mox.StubOutWithMock(trychange.scm.GIT, 'GetEmail')
     self.mox.StubOutWithMock(trychange.scm.GIT, 'GetPatchName')
-    self.mox.StubOutWithMock(trychange.scm.GIT, 'GetEmail')
+    self.mox.StubOutWithMock(trychange.scm.GIT, 'GetUpstreamBranch')
     self.mox.StubOutWithMock(trychange.scm.SVN, 'DiffItem')
     self.mox.StubOutWithMock(trychange.scm.SVN, 'GenerateDiff')
     self.mox.StubOutWithMock(trychange.scm.SVN, 'GetCheckoutRoot')
     self.mox.StubOutWithMock(trychange.scm.SVN, 'GetEmail')
     self.fake_root = self.Dir()
     self.expected_files = ['foo.txt', 'bar.txt']
     self.options = trychange.optparse.Values()
     self.options.files = self.expected_files
     self.options.diff = None
     self.options.name = None
@@ skipping 47 matching lines @@
     members = [
       'AutomagicalSettings', 'GclStyleSettings', 'GclientStyleSettings',
       'GetCodeReviewSetting', 'ReadRootFile',
       'GenerateDiff', 'GetFileNames',
     ]
     # If this test fails, you should add the relevant test.
     self.compareMembers(trychange.GIT, members)
 
   def testBasic(self):
     trychange.scm.GIT.GetCheckoutRoot(self.fake_root).AndReturn(self.fake_root)
+    trychange.scm.GIT.GetUpstreamBranch(self.fake_root).AndReturn('somewhere')
     trychange.scm.GIT.GenerateDiff(self.fake_root,
                                    full_move=True,
                                    files=['foo.txt', 'bar.txt'],
-                                   branch=None).AndReturn('A diff')
+                                   branch='somewhere').AndReturn('A diff')
     trychange.scm.GIT.GetPatchName(self.fake_root).AndReturn('bleh-1233')
     trychange.scm.GIT.GetEmail(self.fake_root).AndReturn('georges@example.com')
     self.mox.ReplayAll()
     git = trychange.GIT(self.options, self.fake_root)
     self.assertEqual(git.GetFileNames(), self.expected_files)
     self.assertEqual(git.checkout_root, self.fake_root)
     self.assertEqual(git.GenerateDiff(), 'A diff')
 
 
 if __name__ == '__main__':
   import unittest
   unittest.main()