Saturday, January 28, 2012

monkeyrunner: testing views properties

There are several questions floating around, like this one in stackoverflow, about how some view properties could be obtained from a monkeyrunner script or putting the question in more general terms:
how a test that verifies some properties can be created using monkeyrunner ?

This is a required feature if we are going to create tests in monkeyrunner otherwise our alternatives to verify some state in the views is limited to visual comparison. These cases were treated in previous articles like:

but now we will be using a logical approach rather than visual comparison. To be able to do it we need a mechanism of obtaining view properties values.
Lastest versions of monkeyrunner provides an extension to MonkeyDevice called EasyMonkeyDevice and this class has methods to get some properties like MonkeyDevice.getText().
This API is not documented so expect changes in the future.
TemperatureConverter, a sample application that has been used in other articles before, will be our application under test. The source code can be obtained from github.

The idea behind this test is, using monkeyrunner to connect to  the device, enter 123 in the Celsius field and expect to find 253.40 in the Fahrenheit field.

#! /usr/bin/env monkeyrunner

import sys
from import MonkeyRunner, MonkeyDevice
from import EasyMonkeyDevice
from import By

# connect to the device
device = MonkeyRunner.waitForConnection()

# start TemperatureConverter

# use the EasyMonkey API
easyDevice = EasyMonkeyDevice(device)

celsiusId ='id/celsius')
if not celsiusId:
   raise Exception("View with id/celsius not found")

fahrenheitId ='id/fahrenheit')
if not fahrenheitId:
   raise Exception("View with id/fahrenheit not found")

easyDevice.type(celsiusId, '123')

celsius = easyDevice.getText(celsiusId)
fahrenheit = easyDevice.getText(fahrenheitId)
expected = '253.40'

if fahrenheit == expected:
   print 'PASS'
   print 'FAIL: expected %s, actual %s' % (expected, fahrenheit)

Unfortunately, it won't work in most of the cases. You are likely to receive this exception:

        java.lang.RuntimeException: java.lang.RuntimeException: No text property on node

I felt frustrated at first, but what the advantage of an Open Source project is other than going to the source code and find out why it's not working.
I dug into the Chimpchat, HierarchyView and ViewServer code and found out that for some reason EasyMonkeyDevice is looking for the text:mText property when in most of the cases it should be only mText.
So here is the patch, that I will be uploading to android soon:

diff --git a/chimpchat/src/com/android/chimpchat/hierarchyviewer/ b/chimpchat/src/com/android/chimpchat/hierarchyviewer/
index 6ad98ad..6c34d71 100644
--- a/chimpchat/src/com/android/chimpchat/hierarchyviewer/
+++ b/chimpchat/src/com/android/chimpchat/hierarchyviewer/
@@ -170,7 +170,11 @@ public class HierarchyViewer {
         ViewNode.Property textProperty = node.namedProperties.get("text:mText");
         if (textProperty == null) {
-            throw new RuntimeException("No text property on node");
+            // dtmilano: give it another chance, ICS ViewServer returns mText
+            textProperty = node.namedProperties.get("mText");
+            if ( textProperty == null ) {
+                throw new RuntimeException("No text property on node");
+            }
         return textProperty.value;
Once this patch is applied and you rebuild monkeyrunner or the entire SDK if you prefer, you will be presented with the expected result: PASS

This patch has been submitted to Android Open Source Project as

UPDATE: July 2012
Android SDK Tools Rev 20 includes the aforementioned patch and now the previous monkeyrunner example works! 

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