[Android] Add DeviceUtils.GetApplicationVersion

build/android/pylib/device/device_utils.py

Index: build/android/pylib/device/device_utils.py
diff --git a/build/android/pylib/device/device_utils.py b/build/android/pylib/device/device_utils.py
index bc1f2ab27339c25b18d03ccac517649c15017c55..0dffa1d55bb52e9f24bf00dd58df0f25970f048b 100644
--- a/build/android/pylib/device/device_utils.py
+++ b/build/android/pylib/device/device_utils.py
@@ -386,6 +386,28 @@ class DeviceUtils(object):
     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.