svndiff.py: add ability to compare before-and-after JSON files, not just raw images

tools/rebaseline.py

 #!/usr/bin/python
 
 '''
 Copyright 2012 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 '''
 
 '''
@@ skipping 83 matching lines @@
     def __init__(self, expectations_root, expectations_filename,
                  actuals_base_url, actuals_filename,
                  tests=None, configs=None, add_new=False):
         self._expectations_root = expectations_root
         self._expectations_filename = expectations_filename
         self._tests = tests
         self._configs = configs
         self._actuals_base_url = actuals_base_url
         self._actuals_filename = actuals_filename
         self._add_new = add_new
-        self._testname_pattern = re.compile('(\S+)_(\S+).png')
+        self._image_filename_re = re.compile(gm_json.IMAGE_FILENAME_PATTERN)
 
     # Returns the full contents of filepath, as a single string.
     # If filepath looks like a URL, try to read it that way instead of as
     # a path on local storage.
     #
     # Raises _InternalException if there is a problem.
     def _GetFileContents(self, filepath):
         if filepath.startswith('http:') or filepath.startswith('https:'):
             try:
                 return urllib2.urlopen(filepath).read()
@@ skipping 63 matching lines @@
         # Read in current expectations.
         expectations_json_filepath = os.path.join(
             self._expectations_root, subdir, self._expectations_filename)
         expectations_dict = gm_json.LoadFromFile(expectations_json_filepath)
 
         # Update the expectations in memory, skipping any tests/configs that
         # the caller asked to exclude.
         skipped_images = []
         if results_to_update:
             for (image_name, image_results) in results_to_update.iteritems():
-                (test, config) = self._testname_pattern.match(image_name).groups()
+                (test, config) = self._image_filename_re.match(image_name).groups()

[borenet, 2013/07/16 18:31:03]

nit: 80 chars

Also, why are we using four space indents in this file?

[epoger, 2013/07/16 18:42:32]

Thanks to Python's whitespace-sensitivity, I couldn't think of a way to break
this line that would work.  Can you?
I guess because my emacs configuration was doing that by default.

If it's OK with you, I would like to commit this CL as-is and fix the spacing
separately.  I have added TODOs in each of these files that are 4-space
indented.

[borenet, 2013/07/16 18:48:37]

It's ugly, but what about:
(test, config) = \
    self._image_filename_re.match(image_name).groups()
?
SGTM

                 if self._tests:
                     if test not in self._tests:
                         skipped_images.append(image_name)
                         continue
                 if self._configs:
                     if config not in self._configs:
                         skipped_images.append(image_name)
                         continue
                 expectations_dict[gm_json.JSONKEY_EXPECTEDRESULTS] \
                                  [image_name] \
@@ skipping 98 matching lines @@
             dry_run=args.dry_run,
             json_base_url=args.actuals_base_url,
             json_filename=args.actuals_filename,
             add_new=args.add_new,
             missing_json_is_fatal=missing_json_is_fatal)
     try:
         rebaseliner.RebaselineSubdir(subdir=subdir, builder=builder)
     except BaseException as e:
         print >> sys.stderr, e
         sys.exit(1)