Test Module Config

Some test modules may require customized setup and tear down steps that cannot be performed within test case itself. Typical examples may include:

• install other apks (in addition to the test apk)
• push some files to the device
• run commands (e.g. adb shell pm ...)

In the past, component teams usually resort to writing a host side test to perform such tasks, which requires understanding of TradeFederation harness and typically increases the complexity of a test module .

Borrowing from CTS, we introduced the concept of test module config to support such tasks, the common tasks list above can be achieved by just a few lines of config. For maximum flexibility, you can even implement your own target preparer, as defined by [ITargetPreparer] (https://source.android.com/reference/com/android/tradefed/targetprep/ITargetPreparer.html) or [ITargetCleaner] (https://source.android.com/reference/com/android/tradefed/targetprep/ITargetCleaner.html), and configure them to use in your own test module config.

A test module config for a test module is a required XML file added to the top level module source folder, named ‘AndroidTest.xml’. The XML follows the format of a configuration file used by TradeFederation test automation harness. Currently the main tags handled via the test module configs are the “target_preparer” and “test” tags.

Target Preparers

A “target_preparer” tag, as the name suggests, defines a target preparer (see ITargetPreparer) that offers a setup method, which gets called before the test module is executed for testing; and if the class referenced in the “target_preparer” tag also implements ITargetCleaner, its teardown method will be invoked after the test module has finished.

To use the built-in common module config, add a new file ‘AndroidTest.xml’ at the top level folder for your test module, and populate it with the following content:

<?xml version="1.0" encoding="utf-8"?>
<!-- [insert standard AOSP copyright here] -->
<configuration description="Test module config for Foo">
<!-- insert options here -->
</configuration>

As an example, we can add the following option tags (at the “insert” comment above):

    <target_preparer class="com.android.tradefed.targetprep.RunCommandTargetPreparer">
        <option name="run-command" value="settings put secure accessibility_enabled 1" />
        <option name="teardown-command" value="settings put secure accessibility_enabled 0" />
    </target_preparer>

The options will configure the test harness to:

1. before test module is invoked, execute shell command “settings put secure accessibility_enabled 1” on device
2. after test module is finished, execute shell command “settings put secure accessibility_enabled 0”

In this particular example, accessibility is enabled/disabled before/after the test module execution, respectively. With a simple example demonstrated, it’s necessary to cover more details on how the “option” tag is used. As shown above, the tag can have two attributes: name, value. The name attribute indicated the name of the option, and is further broken down into two parts separated by a colon: short name for the preparer, and the actual option name offered by the preparer. The exact purpose of value field is dependent on how preparer defined the option: it can be a string, a number, a boolean, or even a file path etc. In the example above, name “run-command:run-command” means that we are setting value for the option “run-command” defined by a target preparer with short name “run-command”; and name “run-command:teardown-command” means that we are setting value for the option “teardown-command” also defined by the same target preparer with short name “run-command”. Here's a summary of the 3 common target preparers:

• class name: PushFilePreparer

  • short name: push-file
  • function: pushes arbitrary files under test case folder into destination on device
  • notes:
    • this preparer can push from folder to folder, or file to file; that is, you cannot push a file under a folder on device: you must specify the destination filename under that folder as well
  • options:
    • push: A push-spec, formatted as ‘/path/to/srcfile.txt->/path/to/destfile.txt’ or ‘/path/to/srcfile.txt->/path/to/destdir/’. May be repeated This path may be relative to the test module directory or the out directory itself.
    • **post-push: **A command to run on the device (with `adb shell <your command>`) after all pushes have been attempted. Typical use case would be using chmod for permissions

• class name: InstallApkSetup

  • **short name:**install-apk
  • function: pushes arbitrary apk files under into destination on device
  • options:
    • test-file-name: the name of the apk to be installed on to device.
    • install-arg: Additional arguments to be passed to the pm install command, including leading dash, e.g. “-d". May be repeated

• class name: RunCommandTargetPreparer

  • short name: run-command
  • function: executes arbitrary shell commands before or after test module execution
  • options:
    • **run-command:**adb shell command to run. May be repeated
    • **teardown-command:**adb shell command to run during teardown phase. May be repeated

Test Class

A test class is the TradeFederation class to use to execute the test.

<test class="com.android.tradefed.testtype.AndroidJUnitTest">
  <option name="package" value="android.test.example.helloworld"/>
  <option name="runner" value="android.support.test.runner.AndroidJUnitRunner"/>
</test>

Here are 3 common test classes:

• class name: GTest

  • short name: gtest
  • function: A Test that runs a native test package on given device.
  • options:
    • **native-test-device-path:**The path on the device where native tests are located.

• class name: InstrumentationTest

  • short name: instrumentation
  • function: A Test that runs an instrumentation test package on given device
  • options:
    • **package:**The manifest package name of the Android test application to run.
    • **class:**The test class name to run.
    • **method:**The test method name to run.

• class name: AndroidJUnitTest

  • function: A Test that runs an instrumentation test package on given device using the android.support.test.runner.AndroidJUnitRunner This is the main way to execute an instrumentation test.