[Android] Add DeviceUtils.GetApplicationVersion

build/android/pylib/device/device_utils.py

 # Copyright 2014 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.
 
 """Provides a variety of device interactions based on adb.
 
 Eventually, this will be based on adb_wrapper.
 """
 # pylint: disable=unused-argument
 
@@ skipping 368 matching lines @@
     apks = []
     for line in output:
       if not line.startswith('package:'):
         raise device_errors.CommandFailedError(
             'pm path returned: %r' % '\n'.join(output), str(self))
       apks.append(line[len('package:'):])
     self._cache['package_apk_paths'][package] = list(apks)
     return apks
 
   @decorators.WithTimeoutAndRetriesFromInstance()
+  def GetApplicationVersion(self, package, timeout=None, retries=None):
+    """Get the version name of a package installed on the device.
+
+    Args:
+      package: Name of the package.
+
+    Returns:
+      A string with the version name or None if the package is not found
+      on the device.
+    """
+    output = self.RunShellCommand(
+        ['dumpsys', 'package', package], check_return=True)
+    if not output:
+      return None

[jbudorick, 2015/08/26 13:01:18]

Should this be an exception, too?

[perezju, 2015/08/26 13:21:12]

This usually means that the app is not installed on the device. And allows to
distinguish between "app not installed on the device" and "something really
wrong/unexpected happened when trying to execute the command". Also is
consistent with, e.g., how |GetApplicationPaths| works, which returns an empty
list when the app is not on the device.

[jbudorick, 2015/08/26 13:22:51]

Seems reasonable.

+    for line in output:
+      line = line.strip()
+      if line.startswith('versionName='):
+        return line[len('versionName='):]
+    raise device_errors.CommandFailedError(
+        'Version name for %s not found on dumpsys output' % package, str(self))
+
+  @decorators.WithTimeoutAndRetriesFromInstance()
   def GetApplicationDataDirectory(self, package, timeout=None, retries=None):
     """Get the data directory on the device for the given package.
 
     Args:
       package: Name of the package.
 
     Returns:
       The package's data directory, or None if the package doesn't exist on the
       device.
     """
@@ skipping 1483 matching lines @@
     return [cls(adb) for adb in adb_wrapper.AdbWrapper.Devices()
             if not blacklisted(adb)]
 
   @decorators.WithTimeoutAndRetriesFromInstance()
   def RestartAdbd(self, timeout=None, retries=None):
     logging.info('Restarting adbd on device.')
     with device_temp_file.DeviceTempFile(self.adb, suffix='.sh') as script:
       self.WriteFile(script.name, _RESTART_ADBD_SCRIPT)
       self.RunShellCommand(['source', script.name], as_root=True)
       self.adb.WaitForDevice()