Fix get_latest_build to return actual latest build

Tools/TestResultServer/handlers/buildershandler_unittest.py

 #!/usr/bin/env python
 # Copyright (C) 2012 Google Inc. 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
@@ skipping 32 matching lines @@
 
     def test_cached_build_json_url(self):
         self.assertEqual(buildershandler.cached_build_json_url('http://base', 'dummybuilder', 12345), 'http://base/json/builders/dummybuilder/builds/12345')
         self.assertEqual(buildershandler.cached_build_json_url('http://base', 'dummybuilder', '12345'), 'http://base/json/builders/dummybuilder/builds/12345')
 
     def test_get_latest_build(self):
         build_data = {'cachedBuilds': ['1', '2', '3'],
                       'currentBuilds': ['3'],
                       'basedir': 'fake'}
         latest_build = buildershandler.get_latest_build(build_data)
-
         self.assertEqual(latest_build, '2')
 
         build_data = {'cachedBuilds': [],
                       'currentBuilds': ['1', '2', '3'],
                       'basedir': 'fake'}
         latest_build = buildershandler.get_latest_build(build_data)
-
         self.assertEqual(latest_build, '1')
 
         build_data = {'cachedBuilds': ['1', '2', '3'],
                       'currentBuilds': ['1', '2', '3'],
                       'basedir': 'fake'}
         latest_build = buildershandler.get_latest_build(build_data)
-
         self.assertEqual(latest_build, '1')
 
         build_data = {'cachedBuilds': [],
                       'currentBuilds': [],
                       'basedir': 'fake'}
         latest_build = buildershandler.get_latest_build(build_data)
+        self.assertEqual(latest_build, None)
 
-        self.assertEqual(latest_build, None)
+        long_list = map(lambda x: str(x), xrange(1000, 1200))
+        current_build = long_list[-1]
+        build_data = {'cachedBuilds': long_list[:],
+                      'currentBuilds': [current_build],
+                      'basedir': 'fake'}
+        latest_build = buildershandler.get_latest_build(build_data)
+        self.assertEqual(latest_build, long_list[-2])
 
     def test_fetch_buildbot_data(self):
         try:
             fetched_urls = []
 
             def fake_fetch_json(url):
                 fetched_urls.append(url)
                 if url == 'http://build.chromium.org/p/chromium.webkit/json/builders':
                     return {'WebKit Win': None, 'WebKit Linux': None, 'WebKit Mac': None, 'WebKit Empty': None}
 
@@ skipping 47 matching lines @@
             expected_json = buildershandler.dump_json(expected_masters)
 
             self.assertEqual(buildbot_data, expected_json)
 
         finally:
             buildershandler.fetch_json = old_fetch_json
 
 
 if __name__ == '__main__':
     unittest.main()