PRESUBMIT: Add check for JSON parse errors + fix JSON

PRESUBMIT.py

 # Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import json
 import os
@@ skipping 321 matching lines @@
         error_descriptions))
   if warning_descriptions:
     results.append(output_api.PresubmitPromptOrNotify(
         'You added one or more #includes of files that are temporarily\n'
         'allowed but being removed. Can you avoid introducing the\n'
         '#include? See relevant DEPS file(s) for details and contacts.',
         warning_descriptions))
   return results
 
 
+def _CheckJSONParseErrors(input_api, output_api):
+  """Check that JSON files do not contain syntax errors."""
+
+  def FilterFile(affected_file):
+    return input_api.os_path.splitext(affected_file.LocalPath())[1] == '.json'
+
+  def GetJSONParseError(input_api, filename):
+    try:
+      contents = input_api.ReadFile(filename)
+      input_api.json.loads(contents)
+    except ValueError as e:
+      return e
+    return None
+
+  results = []
+  for affected_file in input_api.AffectedFiles(
+      file_filter=FilterFile, include_deletes=False):
+    parse_error = GetJSONParseError(input_api,
+                                    affected_file.AbsoluteLocalPath())
+    if parse_error:
+      results.append(output_api.PresubmitError('%s could not be parsed: %s' %
+          (affected_file.LocalPath(), parse_error)))
+  return results
+
+
 def _RunPythonTests(input_api, output_api):
   def join(*args):
     return input_api.os_path.join(input_api.PresubmitLocalPath(), *args)
 
   test_directories = [
     join('tools', 'autoroller', 'unittests'),
   ]
 
   tests = []
   for directory in test_directories:
@@ skipping 44 matching lines @@
                   # TODO(phoglund): should arguably be checked.
                   r'^tools[\\\/]valgrind-webrtc[\\\/].*\.py$',
                   r'^tools[\\\/]valgrind[\\\/].*\.py$',
                   r'^tools[\\\/]win[\\\/].*\.py$',
                   r'^xcodebuild.*[\\\/].*\.py$',),
       disabled_warnings=['F0401',  # Failed to import x
                          'E0611',  # No package y in x
                          'W0232',  # Class has no __init__ method
                         ],
       pylintrc='pylintrc'))
+
   # WebRTC can't use the presubmit_canned_checks.PanProjectChecks function since
   # we need to have different license checks in talk/ and webrtc/ directories.
   # Instead, hand-picked checks are included below.
 
   # Skip long-lines check for DEPS, GN and GYP files.
   long_lines_sources = lambda x: input_api.FilterSourceFile(x,
       black_list=(r'.+\.gyp$', r'.+\.gypi$', r'.+\.gn$', r'.+\.gni$', 'DEPS'))
   results.extend(input_api.canned_checks.CheckLongLines(
       input_api, output_api, maxlen=80, source_file_filter=long_lines_sources))
   results.extend(input_api.canned_checks.CheckChangeHasNoTabs(
       input_api, output_api))
   results.extend(input_api.canned_checks.CheckChangeHasNoStrayWhitespace(
       input_api, output_api))
   results.extend(input_api.canned_checks.CheckChangeTodoHasOwner(
       input_api, output_api))
   results.extend(_CheckNativeApiHeaderChanges(input_api, output_api))
   results.extend(_CheckNoIOStreamInHeaders(input_api, output_api))
   results.extend(_CheckNoFRIEND_TEST(input_api, output_api))
   results.extend(_CheckGypChanges(input_api, output_api))
   results.extend(_CheckUnwantedDependencies(input_api, output_api))
+  results.extend(_CheckJSONParseErrors(input_api, output_api))
   results.extend(_RunPythonTests(input_api, output_api))
   return results
 
 
 def CheckChangeOnUpload(input_api, output_api):
   results = []
   results.extend(_CommonChecks(input_api, output_api))
   results.extend(
       input_api.canned_checks.CheckGNFormatted(input_api, output_api))
   return results
@@ skipping 34 matching lines @@
     for builder in masters[master]:
       if 'presubmit' in builder:
         # Do not trigger presubmit builders, since they're likely to fail
         # (e.g. OWNERS checks before finished code review), and we're running
         # local presubmit anyway.
         pass
       else:
         try_config[master][builder] = ['defaulttests']
 
   return try_config