Add pretty printing for rappor.xml

tools/metrics/common/presubmit_util.py

Index: tools/metrics/common/presubmit_util.py
diff --git a/tools/metrics/common/presubmit_util.py b/tools/metrics/common/presubmit_util.py
new file mode 100644
index 0000000000000000000000000000000000000000..8c6400908bf1142d97094a93a196f95c215dbce0
--- /dev/null
+++ b/tools/metrics/common/presubmit_util.py
@@ -0,0 +1,79 @@
+# Copyright (c) 2015 The Chromium Authors. All rights reserved.

[Alexei Svitkine (slow), 2015/02/17 01:36:54]

Nit: No (c) - remove throughout.

[Steven Holte, 2015/02/17 19:33:38]

Done.

+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import os
+import sys
+import logging
+import shutil
+
+import diff_util
+
+sys.path.insert(1, os.path.join(sys.path[0], '..', '..', 'python'))
+from google import path_utils
+
+def DoPresubmitMain(argv, original_filename, backup_filename, script_name,
+                    prettyFn):
+  """Execute presubmit/pretty printing for the target file.
+
+  Args:
+    argv: command line arguments
+    original_filename: The filename to read from.
+    backup_filename: When pretty printing, move the old file contents here.
+    script_name: The name of the script to run for pretty printing.
+    prettyFn: A function which takes the original xml content and produces
+        pretty printed xml.
+
+  Returns:
+    An exit status.  Non-zero indicates errors.
+  """
+  logging.basicConfig(level=logging.INFO)
+  presubmit = ('--presubmit' in argv)
+
+  # If there is a histograms.xml in the current working directory, use that.

[Alexei Svitkine (slow), 2015/02/17 01:36:54]

Update comment.

[Steven Holte, 2015/02/17 19:33:38]

Done.

+  # Otherwise, use the one residing in the same directory as this script.
+  xml_dir = os.getcwd()
+  if not os.path.isfile(os.path.join(xml_dir, original_filename)):
+    xml_dir = path_utils.ScriptDir()
+
+  xml_path = os.path.join(xml_dir, original_filename)
+
+  # Save the original file content.
+  logging.info('Loading %s...', os.path.relpath(xml_path))
+  with open(xml_path, 'rb') as f:
+    original_xml = f.read()
+
+  # Check there are no CR ('\r') characters in the file.
+  if '\r' in original_xml:
+    logging.error('DOS-style line endings (CR characters) detected - these are '
+                  'not allowed. Please run dos2unix %s', original_filename)
+    return 1
+
+  try:
+    pretty = prettyFn(original_xml)
+  except Error:
+    logging.error('Aborting parsing due to fatal errors.')
+    return 1
+
+  if original_xml == pretty:
+    logging.info('%s is correctly pretty-printed.', original_filename)
+    return 0
+  if presubmit:
+    logging.error('%s is not formatted correctly; run %s to fix.',
+                  original_filename, script_name)
+    return 1
+
+  # Prompt user to consent on the change.
+  if not diff_util.PromptUserToAcceptDiff(
+      original_xml, pretty, 'Is the new version acceptable?'):
+    logging.error('Diff not accepted. Aborting.')
+    return 1
+
+  logging.info('Creating backup file: %s', backup_filename)
+  shutil.move(xml_path, os.path.join(xml_dir, backup_filename))
+
+  with open(xml_path, 'wb') as f:
+    f.write(pretty)
+  logging.info('Updated %s. Don\'t forget to add it to your changelist',
+               xml_path)
+  return 0