[Presubmit tests] Warn when new source files are not added to GN/GYPi files.

PRESUBMIT.py

Index: PRESUBMIT.py
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index fde5a12f590ee156633047c944e71ceb546280b9..0c6562daceb9bd1baa3bbc641e7c6bdf2317b745 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -1944,6 +1944,52 @@ def _AndroidSpecificOnUploadChecks(input_api, output_api):
   results.extend(_CheckAndroidToastUsage(input_api, output_api))
   return results
 
+def _CheckNewSourceFileAddedToGn(input_api, output_api):
+   """Checks new source code files were added to GN files"""
+   new_source_files = []
+   gn_files = []
+
+   """ Get lists of new source code files and GN files in the commit"""
+   for f in input_api.AffectedFiles():
+     if f.LocalPath().endswith('.gn'):
+       gn_files.append(f)
+       continue
+     if f.LocalPath().endswith(('.h', '.c', '.cc', '.m', '.mm', '.java')):
+       for line in f.GenerateScmDiff().splitlines():
+         if line.startswith('@@ -0,0'):

[Dirk Pranke, 2016/08/19 20:42:02]

You don't need to look at the diff. 

f.Action() returns 'A', 'M', 'D' for add/modify/deleted, so you can just look
for f.Action() == 'A'.

[maksims (do not use this acc), 2016/08/23 06:00:18]

Done.

+           new_source_files.append(f.LocalPath())
+           break
+
+   if not new_source_files:
+     return []
+
+   if not gn_files:

[Dirk Pranke, 2016/08/19 20:42:02]

Eventually something like this'll be the right check, but for now some file
lists are still held in .gypi files, so you'd really need to look for changes to
either gn or gypi files, and it might be a bit confusing until we're fully off
of GYP and the files have been deleted.

[maksims (do not use this acc), 2016/08/23 06:00:18]

Done.

+     return [output_api.PresubmitPromptWarning('The following new'
+         ' source code files must be added to GN files:\n    ' +
+         '\n    '.join(new_source_files))]
+
+   """Get a list of new source code files that CAN BE FOUND in the GN files"""
+   source_files_listed = []
+   for ff in new_source_files:
+     head, sep, tail = ff.partition('/')
+     if tail:
+       source_file_match_pattern = tail + '",'
+     else:
+       source_file_match_pattern = ff + '",'
+     for gn in gn_files:
+       for line in gn.GenerateScmDiff().splitlines():
+         if line.endswith(source_file_match_pattern):
+           source_files_listed.append(ff)
+           break
+
+   """Remove files, which has been found in the GN files, from the list"""
+   for f in source_files_listed:
+     if f in new_source_files:
+       new_source_files.remove(f)
+
+   return [output_api.PresubmitPromptWarning('The following new'
+       ' source code files must be added to GN files:\n    ' +
+       '\n    '.join(new_source_files))]
 
 def _CommonChecks(input_api, output_api):
   """Checks common to both upload and commit."""
@@ -1995,6 +2041,7 @@ def _CommonChecks(input_api, output_api):
   results.extend(_CheckJavaStyle(input_api, output_api))
   results.extend(_CheckIpcOwners(input_api, output_api))
   results.extend(_CheckMojoUsesNewWrapperTypes(input_api, output_api))
+  results.extend(_CheckNewSourceFileAddedToGn(input_api, output_api))
 
   if any('PRESUBMIT.py' == f.LocalPath() for f in input_api.AffectedFiles()):
     results.extend(input_api.canned_checks.RunUnitTestsInDirectory(