Update PRESUBMIT check for use counters to handle C++ formatting changes

third_party/WebKit/Source/core/frame/PRESUBMIT.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Blink frame presubmit script
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into gcl.
 """
 
 
 def _RunUseCounterChecks(input_api, output_api):
     for f in input_api.AffectedFiles():
         if f.LocalPath().endswith('UseCounter.cpp'):
-            useCounterCpp = f
+            use_counter_cpp_file = f
             break
     else:
         return []
 
-    largestFoundBucket = 0
-    maximumBucket = 0
+    largest_found_bucket = 0
+    expected_max_bucket = 0
+
     # Looking for a line like "case CSSPropertyGrid: return 453;"
-    bucketFinder = input_api.re.compile(r'.*CSSProperty.*return\s*([0-9]+).*')
+    bucket_finder = input_api.re.compile(
+        r'case CSSProperty\w*?\:\s*?\n?\s+?return (\d+);',

[Nico, 2016/09/30 00:41:18]

why \s+ instead of \s* ?

So `return\n43;` doesn't happen in practice?

[dcheng, 2016/09/30 01:56:38]

I think \s will match \n, since we're matching in multiline mode. I simplified
it a bit overall by replacing \s*?\n?\s+ with just \s+?

[Nico, 2016/09/30 02:24:52]

I mean isn't `\s+?` the same as `\s*` ?

+        input_api.re.MULTILINE)
     # Looking for a line like "int maximumCSSSampleId() { return 452; }"

[Nico, 2016/09/30 00:41:18]

update comment

[dcheng, 2016/09/30 01:56:38]

Done.

-    maximumFinder = input_api.re.compile(
-        r'constexpr int kMaximumCSSSampleId = ([0-9]+);')
-    for line in useCounterCpp.NewContents():
-        bucketMatch = bucketFinder.match(line)
-        if bucketMatch:
-            bucket = int(bucketMatch.group(1))
-            largestFoundBucket = max(largestFoundBucket, bucket)
-        else:
-            maximumMatch = maximumFinder.match(line)
-            if maximumMatch:
-                maximumBucket = int(maximumMatch.group(1))
+    expected_max_finder = input_api.re.compile(
+        r'constexpr int kMaximumCSSSampleId = (\d+);')
+    joined_contents = '\n'.join(use_counter_cpp_file.NewContents())
 
-    if largestFoundBucket != maximumBucket:
+    expected_max_match = expected_max_finder.search(joined_contents)
+    if expected_max_match:
+        expected_max_bucket = int(expected_max_match.group(1))
+
+    for bucket_match in bucket_finder.finditer(joined_contents):
+        bucket = int(bucket_match.group(1))
+        largest_found_bucket = max(largest_found_bucket, bucket)
+
+    if largest_found_bucket != expected_max_bucket:
         if input_api.is_committing:
             message_type = output_api.PresubmitError
         else:
             message_type = output_api.PresubmitPromptWarning
 
         return [message_type(
             'Largest found CSSProperty bucket Id (%d) does not match '
-            'maximumCSSSampleId (%d)' %
-                    (largestFoundBucket, maximumBucket),
-            items=[useCounterCpp.LocalPath()])]
+            'maximumCSSSampleId (%d)' % (
+                largest_found_bucket, expected_max_bucket),
+            items=[use_counter_cpp_file.LocalPath()])]
 
     return []
 
 
 def _RunUmaHistogramChecks(input_api, output_api):
     import sys
 
     original_sys_path = sys.path
     try:
         sys.path = sys.path + [input_api.os_path.join(
@@ skipping 32 matching lines @@
     results.extend(_RunUseCounterChecks(input_api, output_api))
     results.extend(_RunUmaHistogramChecks(input_api, output_api))
     return results
 
 
 def CheckChangeOnCommit(input_api, output_api):
     results = []
     results.extend(_RunUseCounterChecks(input_api, output_api))
     results.extend(_RunUmaHistogramChecks(input_api, output_api))
     return results