presubmit_support: cache the result of ChangedContents.

tests/presubmit_unittest.py

 #!/usr/bin/env python
 # Copyright (c) 2011 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 is too confused.
 # pylint: disable=E1101,E1103,R0201,W0212,W0403
 
@@ skipping 1201 matching lines @@
     presubmit.os.path.isdir(path).AndReturn(False)
     presubmit.gclient_utils.FileRead(path, 'rU').AndReturn('whatever\ncookie')
     presubmit.scm.SVN.CaptureInfo(path).AndReturn(
         {'URL': 'svn:/foo/foo/blat.cc'})
     self.mox.ReplayAll()
     af = presubmit.SvnAffectedFile('foo/blat.cc', 'M')
     self.failUnless(af.ServerPath() == 'svn:/foo/foo/blat.cc')
     self.failUnless(af.LocalPath() == presubmit.normpath('foo/blat.cc'))
     self.failUnless(af.Action() == 'M')
     self.assertEquals(af.NewContents(), ['whatever', 'cookie'])
+    
+  def testAffectedFileNotExists(self):
+    presubmit.os.path.exists('notfound.cc').AndReturn(False)
+    presubmit.gclient_utils.FileRead('notfound.cc', 'rU').AndRaise(IOError)
+    self.mox.ReplayAll()
     af = presubmit.AffectedFile('notfound.cc', 'A')
     self.failUnless(af.ServerPath() == '')
+    self.failUnless(af.NewContents() == [])

[M-A Ruel, 2011/04/27 14:07:43]

nit: I prefer:
self.assertEquals('', af.ServerPath())
self.assertEquals([], af.NewContents())

[ncarter (slow), 2011/04/27 20:55:13]

Done.

 
   def testProperty(self):
     presubmit.scm.SVN.GetFileProperty('foo.cc', 'svn:secret-property'
         ).AndReturn('secret-property-value')
     self.mox.ReplayAll()
     affected_file = presubmit.SvnAffectedFile('foo.cc', 'A')
     # Verify cache coherency.
     self.failUnless(affected_file.Property('svn:secret-property') ==
                     'secret-property-value')
     self.failUnless(affected_file.Property('svn:secret-property') ==
@@ skipping 904 matching lines @@
         whitelist=['^a$', '^b$'],
         blacklist=['a'])
     self.assertEqual(results, [])
     self.checkstdout(
         'Running %s\n' % presubmit.os.path.join('random_directory', 'b'))
 
 
 if __name__ == '__main__':
   import unittest
   unittest.main()