Extensions Docs Server: Fix headings with no IDs

chrome/common/extensions/PRESUBMIT.py

Index: chrome/common/extensions/PRESUBMIT.py
diff --git a/chrome/common/extensions/PRESUBMIT.py b/chrome/common/extensions/PRESUBMIT.py
index 2a8f7bc2fa2f947752b97f63aa0dbfe5e9c13d09..e4a2f7e06448e37a51a894301f39e6d5273b0844 100644
--- a/chrome/common/extensions/PRESUBMIT.py
+++ b/chrome/common/extensions/PRESUBMIT.py
@@ -73,8 +73,23 @@ def _CreateIntegrationTestArgs(affected_files):
                                          _ListFilesInPublic()))
   return args
 
+def _CheckHeadingIDs(input_api):
+  ids_re = re.compile('<h[23].*id=.*?>')
+  headings_re = re.compile('<h[23].*?>')
+  bad_files = []
+  for name in input_api.AbsoluteLocalPaths():
+    if (fnmatch.fnmatch(name, '*%s*' % INTROS_PATH) or
+        fnmatch.fnmatch(name, '*%s*' % ARTICLES_PATH)):
+      contents = input_api.ReadFile(name)
+      if (len(re.findall(headings_re, contents)) !=
+          len(re.findall(ids_re, contents))):
+        bad_files.append(name)
+  return bad_files
+
 def _CheckChange(input_api, output_api):
-  results = []
+  results = [
+      output_api.PresubmitError('File %s needs an id for each heading.' % name)
+      for name in _CheckHeadingIDs(input_api)]
   try:
     integration_test = []
     # From depot_tools/presubmit_canned_checks.py:529