Add presubmit check to prevent package boundary violations.

BUG=webrtc:6954
NOTRY=True

Review-Url: https://codereview.webrtc.org/2629723004
Cr-Commit-Position: refs/heads/master@{#16357}

tools-webrtc/check_package_boundaries_test.py

@@ -0,0 +1,67 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+#
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+
+import ast
+import os
+import unittest
+
+from check_package_boundaries import CheckPackageBoundaries
+
+
+MSG_FORMAT = 'ERROR:check_package_boundaries.py: Unexpected %s.'
+TESTDATA_DIR = os.path.join(os.path.dirname(os.path.abspath(__file__)),
+                            'testdata')
+
+
+def ReadPylFile(file_path):
+  with open(file_path) as f:
+    return ast.literal_eval(f.read())
+
+
+class Logger(object):
+  def __init__(self, test_dir):
+    self.messages = []
+    self.test_dir = test_dir
+
+  def log(self, build_file_path, line_number, target_name, source_file,
+          subpackage):
+    build_file_path = os.path.relpath(build_file_path, self.test_dir)
+    self.messages.append([build_file_path, line_number, target_name,
+                          source_file, subpackage])
+
+
+class UnitTest(unittest.TestCase):
+  def RunTest(self, test_dir, check_all_build_files=False):
+    logger = Logger(test_dir)
+    build_files = [os.path.join(test_dir, 'BUILD.gn')]
+    if check_all_build_files:
+      build_files = None
+    CheckPackageBoundaries(test_dir, logger, build_files)
+    expected_messages = ReadPylFile(os.path.join(test_dir, 'expected.pyl'))
+    self.assertListEqual(sorted(expected_messages), sorted(logger.messages))
+
+  def test_no_errors(self):
+    self.RunTest(os.path.join(TESTDATA_DIR, 'no_errors'))
+
+  def test_multiple_errors_single_target(self):
+    self.RunTest(os.path.join(TESTDATA_DIR, 'multiple_errors_single_target'))
+
+  def test_multiple_errors_multiple_targets(self):
+    self.RunTest(os.path.join(TESTDATA_DIR, 'multiple_errors_multiple_targets'))
+
+  def test_common_prefix(self):
+    self.RunTest(os.path.join(TESTDATA_DIR, 'common_prefix'))
+
+  def test_all_build_files(self):
+    self.RunTest(os.path.join(TESTDATA_DIR, 'all_build_files'), True)
+
+
+if __name__ == '__main__':
+  unittest.main()