[devil] Upgrade parser/serializer for command line flags

devil/devil/android/flag_changer_test.py

Index: devil/devil/android/flag_changer_test.py
diff --git a/devil/devil/android/flag_changer_test.py b/devil/devil/android/flag_changer_test.py
new file mode 100755
index 0000000000000000000000000000000000000000..f692bd62dbc41f1f7287e37d3d07317deb751a54
--- /dev/null
+++ b/devil/devil/android/flag_changer_test.py
@@ -0,0 +1,132 @@
+#!/usr/bin/env python
+# Copyright 2017 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 posixpath
+import unittest
+
+from devil.android import flag_changer
+
+
+_CMDLINE_FILE = 'chrome-command-line'
+
+
+class _FakeDevice(object):
+  def __init__(self):
+    self.build_type = 'user'
+    self.has_root = True
+    self.file_system = {}
+
+  def HasRoot(self):
+    return self.has_root
+
+  def PathExists(self, filepath):
+    return filepath in self.file_system
+
+  def RemovePath(self, path, **_kwargs):
+    self.file_system.pop(path)
+
+  def WriteFile(self, path, contents, **_kwargs):
+    self.file_system[path] = contents
+
+  def ReadFile(self, path, **_kwargs):
+    return self.file_system[path]
+
+
+class FlagChangerTest(unittest.TestCase):
+  def setUp(self):
+    self.device = _FakeDevice()
+    # pylint: disable=protected-access
+    self.cmdline_path = posixpath.join(flag_changer._CMDLINE_DIR, _CMDLINE_FILE)
+    self.cmdline_path_legacy = posixpath.join(
+        flag_changer._CMDLINE_DIR_LEGACY, _CMDLINE_FILE)
+
+  def testFlagChanger_removeLegacyCmdLine(self):
+    self.device.WriteFile(self.cmdline_path_legacy, 'chrome --old --stuff')
+    self.assertTrue(self.device.PathExists(self.cmdline_path_legacy))
+
+    changer = flag_changer.FlagChanger(self.device, 'chrome-command-line')
+    self.assertEquals(
+        changer._cmdline_path,  # pylint: disable=protected-access
+        self.cmdline_path)
+    self.assertFalse(self.device.PathExists(self.cmdline_path_legacy))
+
+
+class ParseSerializeFlagsTest(unittest.TestCase):
+  def _testQuoteFlag(self, flag, expected_quoted_flag):
+    # Start with an unquoted flag, check that it's quoted as expected.
+    # pylint: disable=protected-access
+    quoted_flag = flag_changer._QuoteFlag(flag)
+    self.assertEqual(quoted_flag, expected_quoted_flag)
+    # Check that it survives a round-trip.
+    parsed_flags = flag_changer._ParseFlags('_ %s' % quoted_flag)
+    self.assertEqual(len(parsed_flags), 1)
+    self.assertEqual(flag, parsed_flags[0])
+
+  def testQuoteFlag_simple(self):
+    self._testQuoteFlag('--simple-flag', '--simple-flag')
+
+  def testQuoteFlag_withSimpleValue(self):
+    self._testQuoteFlag('--key=value', '--key=value')
+
+  def testQuoteFlag_withQuotedValue1(self):
+    self._testQuoteFlag('--key=valueA valueB', '--key="valueA valueB"')
+
+  def testQuoteFlag_withQuotedValue2(self):
+    self._testQuoteFlag(
+        '--key=this "should" work', r'--key="this \"should\" work"')
+
+  def testQuoteFlag_withQuotedValue3(self):
+    self._testQuoteFlag(
+        "--key=this is 'fine' too", '''--key="this is 'fine' too"''')
+
+  def testQuoteFlag_withQuotedValue4(self):
+    with self.assertRaises(AssertionError):
+      # TODO(catapult:#3112) This test is broken in the current implementation;
+      # flags that appear to be quoted are left as-is and, thus, do not
+      # survive the round-trip.
+      self._testQuoteFlag(
+          "--key='I really want to keep these quotes'",
+          '''--key="'I really want to keep these quotes'"''')
+
+  def testQuoteFlag_withQuotedValue5(self):
+    self._testQuoteFlag(
+        "--this is a strange=flag", '"--this is a strange=flag"')
+
+  def _testParseCmdLine(self, command_line, expected_flags):
+    # Start with a command line, check that flags are parsed as expected.
+    # pylint: disable=protected-access
+    flags = flag_changer._ParseFlags(command_line)
+    self.assertItemsEqual(flags, expected_flags)
+
+    # Check that flags survive a round-trip.
+    # Note: Although new_command_line and command_line may not match, they
+    # should describe the same set of flags.
+    new_command_line = flag_changer._SerializeFlags(flags)
+    new_flags = flag_changer._ParseFlags(new_command_line)
+    self.assertItemsEqual(new_flags, expected_flags)
+
+  def testParseCmdLine_simple(self):
+    self._testParseCmdLine(
+        'chrome --foo --bar="a b" --baz=true --fine="ok"',
+        ['--foo', '--bar=a b', '--baz=true', '--fine=ok'])
+
+  def testParseCmdLine_withFancyQuotes(self):
+    self._testParseCmdLine(
+        r'''_ --foo="this 'is' ok"
+              --bar='this \'is\' too'
+              --baz="this \'is\' tricky"
+        ''',
+        ["--foo=this 'is' ok",
+         "--bar=this 'is' too",
+         r"--baz=this \'is\' tricky"])
+
+  def testParseCmdLine_withUnterminatedQuote(self):
+    self._testParseCmdLine(
+        '_ --foo --bar="I forgot something',
+        ['--foo', '--bar=I forgot something'])
+
+
+if __name__ == '__main__':
+  unittest.main(verbosity=2)