new tool: download all GM images for a given builder, ready for skdiff

gm/rebaseline_server/download_test.py

 #!/usr/bin/python
 
 """
-Copyright 2013 Google Inc.
+Copyright 2014 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 
-Test results.py
+Test download.py
 
 TODO(epoger): Create a command to update the expected results (in
 OUTPUT_DIR_EXPECTED) when appropriate.  For now, you should:
 1. examine the results in OUTPUT_DIR_ACTUAL and make sure they are ok
 2. rm -rf OUTPUT_DIR_EXPECTED
 3. mv OUTPUT_DIR_ACTUAL OUTPUT_DIR_EXPECTED
 Although, if you're using an SVN checkout, this will blow away .svn directories
 within OUTPUT_DIR_EXPECTED, which wouldn't be good...
 
 """
 
+# System-level imports
 import filecmp
 import os
 import shutil
-import sys
 import tempfile
 import unittest
+import url_or_path
 
 # Imports from within Skia
-import results
-import gm_json  # must import results first, so that gm_json will be in sys.path
+import download
 
 PARENT_DIR = os.path.dirname(os.path.realpath(__file__))
 INPUT_DIR = os.path.join(PARENT_DIR, 'tests', 'inputs')
 OUTPUT_DIR_ACTUAL   = os.path.join(PARENT_DIR, 'tests', 'outputs', 'actual')
 OUTPUT_DIR_EXPECTED = os.path.join(PARENT_DIR, 'tests', 'outputs', 'expected')
 
 
-class ResultsTest(unittest.TestCase):
+class DownloadTest(unittest.TestCase):
 
   def setUp(self):
     self._temp_dir = tempfile.mkdtemp()
     self._output_dir_actual   = os.path.join(OUTPUT_DIR_ACTUAL, self.id())
     self._output_dir_expected = os.path.join(OUTPUT_DIR_EXPECTED, self.id())
     create_empty_dir(self._output_dir_actual)
 
   def tearDown(self):
     shutil.rmtree(self._temp_dir)
     different_files = find_different_files(self._output_dir_actual,
@@ skipping 11 matching lines @@
     # Ravi notes: if somebody later comes along and adds cleanup code below the
     # assert, then if tests fail, the artifacts will not be cleaned up.
     assert (not different_files), \
       ('found differing files between actual dir %s and expected dir %s: %s' %
        (self._output_dir_actual, self._output_dir_expected, different_files))
 
   def shortDescription(self):
     """Tell unittest framework to not print docstrings for test cases."""
     return None
 
-  def test_gm(self):
-    """Process results of a GM run with the Results object."""
-    results_obj = results.Results(
-        actuals_root=os.path.join(INPUT_DIR, 'gm-actuals'),
-        expected_root=os.path.join(INPUT_DIR, 'gm-expectations'),
-        generated_images_root=self._temp_dir)
-    gm_json.WriteToFile(results_obj.get_results_of_type(results.RESULTS_ALL),
-                        os.path.join(self._output_dir_actual, 'gm.json'))
+  def test_fetch(self):
+    """Tests fetch() of GM results from actual-results.json ."""
+    downloader = download.Download(
+        actuals_base_url=os.path.join(INPUT_DIR, 'gm-actuals'),
+        gm_actuals_root_url=url_or_path.create_filepath_url(
+            os.path.join(INPUT_DIR, 'fake-gm-imagefiles')))
+    downloader.fetch(
+        builder_name='Test-Android-GalaxyNexus-SGX540-Arm7-Release',
+        dest_dir=self._output_dir_actual)
 
 
+# TODO(epoger): create_empty_dir(), find_different_files(), etc. should be
+# extracted from this file to some common location, where they can be shared
+# with results_test.py and other users.
+
 def create_empty_dir(path):
   """Create an empty directory at the given path."""
   if os.path.isdir(path):
     shutil.rmtree(path)
   elif os.path.lexists(path):
     os.remove(path)
   os.makedirs(path)
 
 
 def find_different_files(dir1, dir2, ignore_subtree_names=None):
@@ skipping 18 matching lines @@
   differing_files.extend(dircmp.common_funny)
   differing_files.extend(dircmp.diff_files)
   differing_files.extend(dircmp.funny_files)
   for common_dir in dircmp.common_dirs:
     differing_files.extend(find_different_files(
         os.path.join(dir1, common_dir), os.path.join(dir2, common_dir)))
   return differing_files
 
 
 def main():
-  suite = unittest.TestLoader().loadTestsFromTestCase(ResultsTest)
+  suite = unittest.TestLoader().loadTestsFromTestCase(DownloadTest)
   unittest.TextTestRunner(verbosity=2).run(suite)
 
 
 if __name__ == '__main__':
   main()