Migrate DeviceUtils.SetJavaAsserts to adb_wrapper

The implementation mirrors that of android_commands, but is hopefully
clearer and more efficient. ReadFile/WriteFile are used to read
persistent properties first, and then GetProp/SetProp are used for
the current runtime properties.

BUG=267773

Review URL: https://codereview.chromium.org/776303002

Cr-Commit-Position: refs/heads/master@{#314791}

build/android/pylib/device/device_utils.py

@@ -104,6 +104,9 @@ class DeviceUtils(object):
   _MAX_ADB_COMMAND_LENGTH = 512
   _VALID_SHELL_VARIABLE = re.compile('^[a-zA-Z_][a-zA-Z0-9_]*$')
 
+  # Property in /data/local.prop that controls Java assertions.
+  JAVA_ASSERT_PROPERTY = 'dalvik.vm.enableassertions'
+
   def __init__(self, device, default_timeout=_DEFAULT_TIMEOUT,
                default_retries=_DEFAULT_RETRIES):
     """DeviceUtils constructor.
@@ -1041,7 +1044,43 @@ class DeviceUtils(object):
     Raises:
       CommandTimeoutError on timeout.
     """
-    return self.old_interface.SetJavaAssertsEnabled(enabled)
+    def find_property(lines, property_name):
+      for index, line in enumerate(lines):
+        key, value = (s.strip() for s in line.split('=', 1))
+        if key == property_name:
+          return index, value
+      return None, ''
+
+    new_value = 'all' if enabled else ''
+
+    # First ensure the desired property is persisted.
+    try:
+      properties = self.ReadFile(
+          constants.DEVICE_LOCAL_PROPERTIES_PATH).splitlines()
+    except device_errors.CommandFailedError:
+      properties = []
+    index, value = find_property(properties, self.JAVA_ASSERT_PROPERTY)
+    if new_value != value:
+      if new_value:
+        new_line = '%s=%s' % (self.JAVA_ASSERT_PROPERTY, new_value)
+        if index is None:
+          properties.append(new_line)
+        else:
+          properties[index] = new_line
+      else:
+        assert index is not None # since new_value == '' and new_value != value
+        properties.pop(index)
+      self.WriteFile(constants.DEVICE_LOCAL_PROPERTIES_PATH,
+                     _JoinLines(properties))
+
+    # Next, check the current runtime value is what we need, and
+    # if not, set it and report that a reboot is required.
+    value = self.GetProp(self.JAVA_ASSERT_PROPERTY)
+    if new_value != value:
+      self.SetProp(self.JAVA_ASSERT_PROPERTY, new_value)
+      return True
+    else:
+      return False
 
 
   @property

build/android/pylib/device/device_utils_test.py

@@ -1238,81 +1238,44 @@ class DeviceUtilsStatTest(DeviceUtilsNewImplTest):
         self.device.Stat('/data/local/tmp/does.not.exist.txt')
 
 
-class DeviceUtilsSetJavaAssertsTest(DeviceUtilsOldImplTest):
-
-  @staticmethod
-  def mockNamedTemporary(name='/tmp/file/property.file',
-                         read_contents=''):
-    mock_file = mock.MagicMock(spec=file)
-    mock_file.name = name
-    mock_file.__enter__.return_value = mock_file
-    mock_file.read.return_value = read_contents
-    return mock_file
+class DeviceUtilsSetJavaAssertsTest(DeviceUtilsNewImplTest):
 
   def testSetJavaAsserts_enable(self):
-    mock_file = self.mockNamedTemporary()
-    with mock.patch('tempfile.NamedTemporaryFile',
-                    return_value=mock_file), (
-         mock.patch('__builtin__.open', return_value=mock_file)):
-      with self.assertCallsSequence(
-          [('adb -s 0123456789abcdef shell ls %s' %
-                constants.DEVICE_LOCAL_PROPERTIES_PATH,
-            '%s\r\n' % constants.DEVICE_LOCAL_PROPERTIES_PATH),
-           ('adb -s 0123456789abcdef pull %s %s' %
-                (constants.DEVICE_LOCAL_PROPERTIES_PATH, mock_file.name),
-            '100 B/s (100 bytes in 1.000s)\r\n'),
-           ('adb -s 0123456789abcdef push %s %s' %
-                (mock_file.name, constants.DEVICE_LOCAL_PROPERTIES_PATH),
-            '100 B/s (100 bytes in 1.000s)\r\n'),
-           ('adb -s 0123456789abcdef shell '
-                'getprop dalvik.vm.enableassertions',
-            '\r\n'),
-           ('adb -s 0123456789abcdef shell '
-                'setprop dalvik.vm.enableassertions "all"',
-            '')]):
-        self.assertTrue(self.device.SetJavaAsserts(True))
+    with self.assertCalls(
+        (self.call.device.ReadFile(constants.DEVICE_LOCAL_PROPERTIES_PATH),
+         'some.example.prop=with an example value\n'
+         'some.other.prop=value_ok\n'),
+        self.call.device.WriteFile(
+            constants.DEVICE_LOCAL_PROPERTIES_PATH,
+            'some.example.prop=with an example value\n'
+            'some.other.prop=value_ok\n'
+            'dalvik.vm.enableassertions=all\n'),
+        (self.call.device.GetProp('dalvik.vm.enableassertions'), ''),
+        self.call.device.SetProp('dalvik.vm.enableassertions', 'all')):
+      self.assertTrue(self.device.SetJavaAsserts(True))
 
   def testSetJavaAsserts_disable(self):
-    mock_file = self.mockNamedTemporary(
-        read_contents='dalvik.vm.enableassertions=all\n')
-    with mock.patch('tempfile.NamedTemporaryFile',
-                    return_value=mock_file), (
-         mock.patch('__builtin__.open', return_value=mock_file)):
-      with self.assertCallsSequence(
-          [('adb -s 0123456789abcdef shell ls %s' %
-                constants.DEVICE_LOCAL_PROPERTIES_PATH,
-            '%s\r\n' % constants.DEVICE_LOCAL_PROPERTIES_PATH),
-           ('adb -s 0123456789abcdef pull %s %s' %
-                (constants.DEVICE_LOCAL_PROPERTIES_PATH, mock_file.name),
-            '100 B/s (100 bytes in 1.000s)\r\n'),
-           ('adb -s 0123456789abcdef push %s %s' %
-                (mock_file.name, constants.DEVICE_LOCAL_PROPERTIES_PATH),
-            '100 B/s (100 bytes in 1.000s)\r\n'),
-           ('adb -s 0123456789abcdef shell '
-                'getprop dalvik.vm.enableassertions',
-            'all\r\n'),
-           ('adb -s 0123456789abcdef shell '
-                'setprop dalvik.vm.enableassertions ""',
-            '')]):
-        self.assertTrue(self.device.SetJavaAsserts(False))
+    with self.assertCalls(
+        (self.call.device.ReadFile(constants.DEVICE_LOCAL_PROPERTIES_PATH),
+         'some.example.prop=with an example value\n'
+         'dalvik.vm.enableassertions=all\n'
+         'some.other.prop=value_ok\n'),
+        self.call.device.WriteFile(
+            constants.DEVICE_LOCAL_PROPERTIES_PATH,
+            'some.example.prop=with an example value\n'
+            'some.other.prop=value_ok\n'),
+        (self.call.device.GetProp('dalvik.vm.enableassertions'), 'all'),
+        self.call.device.SetProp('dalvik.vm.enableassertions', '')):
+      self.assertTrue(self.device.SetJavaAsserts(False))
 
   def testSetJavaAsserts_alreadyEnabled(self):
-    mock_file = self.mockNamedTemporary(
-        read_contents='dalvik.vm.enableassertions=all\n')
-    with mock.patch('tempfile.NamedTemporaryFile',
-                    return_value=mock_file), (
-         mock.patch('__builtin__.open', return_value=mock_file)):
-      with self.assertCallsSequence(
-          [('adb -s 0123456789abcdef shell ls %s' %
-                constants.DEVICE_LOCAL_PROPERTIES_PATH,
-            '%s\r\n' % constants.DEVICE_LOCAL_PROPERTIES_PATH),
-           ('adb -s 0123456789abcdef pull %s %s' %
-                (constants.DEVICE_LOCAL_PROPERTIES_PATH, mock_file.name),
-            '100 B/s (100 bytes in 1.000s)\r\n'),
-           ('adb -s 0123456789abcdef shell '
-                'getprop dalvik.vm.enableassertions',
-            'all\r\n')]):
-        self.assertFalse(self.device.SetJavaAsserts(True))
+    with self.assertCalls(
+        (self.call.device.ReadFile(constants.DEVICE_LOCAL_PROPERTIES_PATH),
+         'some.example.prop=with an example value\n'
+         'dalvik.vm.enableassertions=all\n'
+         'some.other.prop=value_ok\n'),
+        (self.call.device.GetProp('dalvik.vm.enableassertions'), 'all')):
+      self.assertFalse(self.device.SetJavaAsserts(True))
 
 
 class DeviceUtilsGetPropTest(DeviceUtilsNewImplTest):