Add a presubmit check for blink/public/web dependencies in chrome/browser

As part of crbug.com/1008303 we are removing all the blink/public/web
dependencies from chrome/browser. It would be nice to add a presubmit check so
that new dependencies are not added in the meantime.

Bug: 1008303
Change-Id: Id6aee21e4c64271b0c1e00cdffc848de88bb4629
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1879921
Commit-Queue: Sergio Villar <svillar@igalia.com>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: David Roger <droger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713391}

chrome/browser/PRESUBMIT.py

@@ -4,6 +4,8 @@
 
 """Presubmit script for Chromium browser code."""
 
+import re
+
 def _RunHistogramChecks(input_api, output_api, histogram_name):
   try:
     # Setup sys.path so that we can call histograms code.
@@ -25,10 +27,32 @@ def _RunHistogramChecks(input_api, output_api, histogram_name):
   finally:
     sys.path = original_sys_path
 
+def _CheckUnwantedDependencies(input_api, output_api):
+  problems = []
+  for f in input_api.AffectedFiles():
+    if not f.LocalPath().endswith('DEPS'):
+      continue
+
+    for line_num, line in f.ChangedContents():
+      if not line.strip().startswith('#'):
+        m = re.search(r".*\/blink\/public\/web.*", line)
+        if m:
+          problems.append(m.group(0))
+
+  if not problems:
+    return []
+  return [output_api.PresubmitPromptWarning(
+      'chrome/browser cannot depend on blink/public/web interfaces. ' +
+      'Use blink/public/common instead.',
+      items=problems)]
 
 def _CommonChecks(input_api, output_api):
   """Checks common to both upload and commit."""
-  return _RunHistogramChecks(input_api, output_api, "BadMessageReasonChrome")
+  results = []
+  results.extend(_CheckUnwantedDependencies(input_api, output_api))
+  results.extend(_RunHistogramChecks(input_api, output_api,
+                 "BadMessageReasonChrome"))
+  return results
 
 
 def CheckChangeOnUpload(input_api, output_api):

chrome/browser/PRESUBMIT_test.py

+#!/usr/bin/env python
+# Copyright (c) 2019 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.
+
+import os.path
+import subprocess
+import sys
+import unittest
+
+import PRESUBMIT
+
+file_dir_path = os.path.dirname(os.path.abspath(__file__))
+sys.path.insert(0, os.path.join(file_dir_path, '..', '..'))
+from PRESUBMIT_test_mocks import MockFile, MockAffectedFile
+from PRESUBMIT_test_mocks import MockInputApi, MockOutputApi
+
+_VALID_DEP = "+third_party/blink/public/platform/web_something.h,"
+_INVALID_DEP = "+third_party/blink/public/web/web_something.h,"
+_INVALID_DEP2 = "+third_party/blink/public/web/web_nothing.h,"
+
+class BlinkPublicWebUnwantedDependenciesTest(unittest.TestCase):
+  def makeInputApi(self, files):
+    input_api = MockInputApi()
+    input_api.files = files
+    # Override os_path.exists because the presubmit uses the actual
+    # os.path.exists.
+    input_api.CreateMockFileInPath(
+        [x.LocalPath() for x in input_api.AffectedFiles(include_deletes=True)])
+    return input_api
+
+  INVALID_DEPS_MESSAGE = ('chrome/browser cannot depend on '
+                          'blink/public/web interfaces. Use'
+                          ' blink/public/common instead.')
+
+  def testAdditionOfUnwantedDependency(self):
+    input_api = self.makeInputApi([
+        MockAffectedFile('DEPS', [_INVALID_DEP], [], action='M')])
+    warnings = PRESUBMIT._CheckUnwantedDependencies(input_api, MockOutputApi())
+    self.assertEqual(1, len(warnings))
+    self.assertEqual(self.INVALID_DEPS_MESSAGE, warnings[0].message)
+    self.assertEqual(1, len(warnings[0].items))
+
+  def testAdditionOfUnwantedDependencyInComment(self):
+    input_api = self.makeInputApi([
+        MockAffectedFile('DEPS', ["#" + _INVALID_DEP], [], action='M')])
+    warnings = PRESUBMIT._CheckUnwantedDependencies(input_api, MockOutputApi())
+    self.assertEqual([], warnings)
+
+  def testAdditionOfValidDependency(self):
+    input_api = self.makeInputApi([
+        MockAffectedFile('DEPS', [_VALID_DEP], [], action='M')])
+    warnings = PRESUBMIT._CheckUnwantedDependencies(input_api, MockOutputApi())
+    self.assertEqual([], warnings)
+
+  def testAdditionOfMultipleUnwantedDependency(self):
+    input_api = self.makeInputApi([
+        MockAffectedFile('DEPS', [_INVALID_DEP, _INVALID_DEP2], action='M')])
+    warnings = PRESUBMIT._CheckUnwantedDependencies(input_api, MockOutputApi())
+    self.assertEqual(1, len(warnings))
+    self.assertEqual(self.INVALID_DEPS_MESSAGE, warnings[0].message)
+    self.assertEqual(2, len(warnings[0].items))
+
+    input_api = self.makeInputApi([
+        MockAffectedFile('DEPS', [_INVALID_DEP, _VALID_DEP], [], action='M')])
+    warnings = PRESUBMIT._CheckUnwantedDependencies(input_api, MockOutputApi())
+    self.assertEqual(1, len(warnings))
+    self.assertEqual(self.INVALID_DEPS_MESSAGE, warnings[0].message)
+    self.assertEqual(1, len(warnings[0].items))
+
+  def testRemovalOfUnwantedDependency(self):
+    input_api = self.makeInputApi([
+        MockAffectedFile('DEPS', [], [_INVALID_DEP], action='M')])
+    warnings = PRESUBMIT._CheckUnwantedDependencies(input_api, MockOutputApi())
+    self.assertEqual([], warnings)
+
+  def testRemovalOfValidDependency(self):
+    input_api = self.makeInputApi([
+        MockAffectedFile('DEPS', [], [_VALID_DEP], action='M')])
+    warnings = PRESUBMIT._CheckUnwantedDependencies(input_api, MockOutputApi())
+    self.assertEqual([], warnings)
+
+if __name__ == '__main__':
+  unittest.main()