Running Android instrumentation tests with Mobly

This tutorial shows how to write and execute Mobly tests for running Android instrumentation tests. For more details about instrumentation tests, please refer to https://developer.android.com/studio/test/index.html.

Setup Requirements

• A computer with at least 1 USB ports.
• Mobly package and its system dependencies installed on the computer.
• One Android device that is compatible with your instrumentatation and application apks.
• Your instrumentation and applications apks for installing.
• A working adb setup. To check, connect one Android device to the computer and make sure it has “USB debugging” enabled. Make sure the device shows up in the list printed by adb devices.

Example Name Substitutions

Here are the names that we use in this tutorial, substitute these names with your actual apk package and file names when using your real files:

• The application apk : application.apk
• The instrumentation apk : instrumentation_test.apk
• The instrumentation test package : com.example.package.test

Example 1: Running Instrumentation Tests

Assuming your apks are already installed on devices. You can just subclass the instrumentation test class and run against your package.

You will need a configuration file for Mobly to find your devices.

sample_config.yml

TestBeds:
  - Name: BasicTestBed
    Controllers:
        AndroidDevice: '*'

instrumentation_test.py

from mobly import base_instrumentation_test
from mobly import test_runner
from mobly.controllers import android_device

class InstrumentationTest(base_instrumentation_test.BaseInstrumentationTestClass):
    def setup_class(self):
        self.dut = self.register_controller(android_device)[0]

    def test_instrumentation(self):
        self.run_instrumentation_test(self.dut, 'com.example.package.test')


if __name__ == '__main__':
  test_runner.main()

To execute:

$ python instrumentation_test.py -c sample_config.yml

Expect:

The output from normally running your instrumentation tests along with a summary of the test results.

Example 2: Specifying Instrumentation Options

If your instrumentation tests use instrumentation options for controlling behaviour, then you can put these options into your configuration file and then fetch them when you run your instrumentatation tests.

sample_config.yml

TestBeds:
  - Name: BasicTestBed
    Controllers:
        AndroidDevice: '*'
    TestParams:
        instrumentation_option_annotation: android.support.test.filters.LargeTest
        instrumentation_option_nonAnnotation: android.support.test.filters.SmallTest

instrumentation_test.py

from mobly import base_instrumentation_test
from mobly import test_runner
from mobly.controllers import android_device

class InstrumentationTest(base_instrumentation_test.BaseInstrumentationTestClass):
    def setup_class(self):
        self.dut = self.register_controller(android_device)[0]
        self.options = self.parse_instrumentation_options(self.user_params)

    def test_instrumentation(self):
        self.run_instrumentation_test(self.dut, 'com.example.package.test',
            options=self.options)


if __name__ == '__main__':
  test_runner.main()

To execute:

$ python instrumentation_test.py -c sample_config.yml

Expect:

The output of your LargeTest instrumentation tests with no SmallTest instrumentation test being run.

Example 3 Using a Custom Runner

If you have a custom runner that you use for instrumentation tests, then you can specify it in the run_instrumentation_test method call. Replace com.example.package.test.CustomRunner with the fully quailied package name of your real instrumentation runner.

def test_instrumentation(self):
  self.run_instrumentation_test(self.dut, 'com.example.package.test',
      runner='com.example.package.test.CustomRunner')

Example 4: Multiple Instrumentation Runs

If you have multiple devices that you want to run instrumentation tests against, then you can simply call the run_instrumentation_test method multiple times. If you need to distinguish between runs, then you can specify a prefix.

sample_config.yml

TestBeds:
  - Name: TwoDeviceTestBed
    Controllers:
        AndroidDevice:
          - serial: xyz
            label: dut
          - serial: abc
            label: dut

instrumentation_test.py

from mobly import base_instrumentation_test
from mobly import test_runner
from mobly.controllers import android_device

class InstrumentationTest(base_instrumentation_test.BaseInstrumentationTestClass):
    def setup_class(self):
        self.ads = self.register_controller(android_device)
        # Get all of the dut devices to run instrumentation tests against.
        self.duts = android_device.get_devices(self.ads, label='dut')

    def test_instrumentation(self):
        # Iterate over the dut devices with a corresponding index.
        for index, dut in enumerate(self.duts):
            # Specify a prefix to help disambiguate the runs.
            self.run_instrumentation_test(dut, 'com.example.package.tests',
                prefix='test_run_%s' % index)


if __name__ == '__main__':
  test_runner.main()

To execute:

$ python instrumentation_test.py -c sample_config.yml

Expect:

The output from both instrumentation runs along with an aggregated summary of the results from both runs.