Add presubmit warning to update references to (re)moved OWNERS files

file:// references in OWNERS files can become invalid when the file
is moved or deleted.

Bug: 1385205
Change-Id: Icf1a65b3d96d6ad298eac6645d8f692cb09dc75a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4029143
Auto-Submit: Victor Vianna <victorvianna@google.com>
Reviewed-by: Josip Sokcevic <sokcevic@google.com>
Commit-Queue: Victor Vianna <victorvianna@google.com>

presubmit_canned_checks.py

@@ -2081,3 +2081,21 @@ def CheckInclusiveLanguage(input_api, output_api,
         output_api.PresubmitError('Banned non-inclusive language was used.\n' +
                                   '\n'.join(errors)))
   return result
+
+
+def CheckUpdateOwnersFileReferences(input_api, output_api):
+  """Checks whether an OWNERS file is being (re)moved and if so asks the
+    contributor to update any file:// references to it."""
+  files = []
+  # AffectedFiles() includes owner files, not AffectedSourceFiles().
+  for f in input_api.AffectedFiles():
+    # Moved files appear here as one deletion and one addition.
+    if f.LocalPath().endswith('OWNERS') and f.Action() == 'D':
+      files.append(f.LocalPath())
+  if not files:
+    return []
+  return [
+      output_api.PresubmitPromptWarning(
+          'OWNERS files being moved/removed, please update any file:// ' +
+          'references to them in other OWNERS files', files)
+  ]

presubmit_canned_checks_test.py

@@ -241,5 +241,39 @@ class DescriptionChecksTest(unittest.TestCase):
     self.assertEqual(0, len(errors))
 
 
+class CheckUpdateOwnersFileReferences(unittest.TestCase):
+  def testShowsWarningIfDeleting(self):
+    input_api = MockInputApi()
+    input_api.files = [
+        MockFile('foo/OWNERS', [], [], action='D'),
+    ]
+    results = presubmit_canned_checks.CheckUpdateOwnersFileReferences(
+        input_api, MockOutputApi())
+    self.assertEqual(1, len(results))
+    self.assertEqual('warning', results[0].type)
+    self.assertEqual(1, len(results[0].items))
+
+  def testShowsWarningIfMoving(self):
+    input_api = MockInputApi()
+    input_api.files = [
+        MockFile('new_directory/OWNERS', [], [], action='A'),
+        MockFile('old_directory/OWNERS', [], [], action='D'),
+    ]
+    results = presubmit_canned_checks.CheckUpdateOwnersFileReferences(
+        input_api, MockOutputApi())
+    self.assertEqual(1, len(results))
+    self.assertEqual('warning', results[0].type)
+    self.assertEqual(1, len(results[0].items))
+
+  def testNoWarningIfAdding(self):
+    input_api = MockInputApi()
+    input_api.files = [
+        MockFile('foo/OWNERS', [], [], action='A'),
+    ]
+    results = presubmit_canned_checks.CheckUpdateOwnersFileReferences(
+        input_api, MockOutputApi())
+    self.assertEqual(0, len(results))
+
+
 if __name__ == '__main__':
   unittest.main()

presubmit_canned_checks_test_mocks.py

@@ -79,7 +79,7 @@ class MockInputApi(object):
   def CreateMockFileInPath(self, f_list):
     self.os_path.exists = lambda x: x in f_list
 
-  def AffectedFiles(self, file_filter=None, include_deletes=False):
+  def AffectedFiles(self, file_filter=None, include_deletes=True):
     for file in self.files: # pylint: disable=redefined-builtin
       if file_filter and not file_filter(file):
         continue