Testing In Eclipse, with ADT

This topic explains how create and run tests of Android applications in Eclipse with ADT. with the basic processes for creating and running applications with ADT, as described in Developing In Eclipse, with ADT. Before you read this topic, you should read about how to create a Android application with the basic processes for creating and running applications with ADT, as described in Developing In Eclipse, with ADT. You may also want to read Testing and Instrumentation, which provides an overview of the Android testing framework.

ADT provides several features that help you set up and manage your testing environment effectively:

• It lets you quickly create a test project and link it to the application under test. When it creates the test project, it automatically inserts the necessary <instrumentation> element in the test application's manifest file.
• It lets you quickly import the classes of the application under test, so that your tests can inspect them.
• It lets you create run configurations for your test application and include in them flags that are passed to the Android testing framework.
• It lets you run your test application without leaving Eclipse. ADT builds both the application under test and the test application automatically, installs them if necessary to your device or emulator, runs the test application, and displays the results in a separate window in Eclipse.

If you are not developing in Eclipse or you want to learn how to create and run tests from the command line, see Testing in Other IDEs.

Creating a Test Project

To set up a test environment for your Android application, you must first create a separate application project that holds the test code. The new project follows the directory structure used for any Android application. It includes the same types of content and files, such as source code, resources, a manifest file, and so forth. The test application you create is connected to the application under test by an <instrumentation> element in its manifest file.

The New Android Test Project dialog makes it easy for you to generate a new test project that has the proper structure, including the <instrumentation> element in the manifest file. You can use the New Android Test Project dialog to generate the test project at any time. The dialog appears just after you create a new Android main application project, but you can also run it to create a test project for a project that you created previously.

To create a test project in Eclipse with ADT:

1. In Eclipse, select File > New > Other. This opens the Select a Wizard dialog.
2. In the dialog, in the Wizards drop-down list, find the entry for Android, then click the toggle to the left. Select Android Test Project, then at the bottom of the dialog click Next. The New Android Test Project wizard appears.
3. Enter a project name. You may use any name, but you may want to associate the name with the project name for your Application. One way to do this is to take the Application's project name, append the string "Test" to it, and then use this as the test case project name.
4. In the Test Target panel, set An Existing Android Project, click Browse, then select your Android application from the list. You now see that the wizard has completed the Test Target Package, Application Name, and Package Name fields for you (the latter two are in the Properties panel).
5. In the Build Target panel, select the Android SDK platform that you will use to test your application. Make this the same as the build target of the application under test.
6. Click Finish to complete the wizard. If Finish is disabled, look for error messages at the top of the wizard dialog, and then fix any problems.

Creating a Test Application

Once you have created a test project, you populate it with a test Android application. This application does not require an Activity, although you can define one if you wish. Although your test application can combine Activities, Android test class extensions, JUnit extensions, or ordinary classes, you should extend one of the Android test classes or JUnit classes, because these provide the best testing features.

Test applications do not have an Android GUI. Instead, when you run the application in Eclipse with ADT, its results appear in the JUnit view. If you run your tests with InstrumentationTestRunner (or a related test runner), then it will run all the methods in each class. You can modify this behavior by using the TestSuite class.

To create a test application, start with one of Android's test classes in the Java package android.test. These extend the JUnit TestCase class. With a few exceptions, the Android test classes also provide instrumentation for testing.

For test classes that extend TestCase, you probably want to override the setUp() and tearDown() methods:

• setUp(): This method is invoked before any of the test methods in the class. Use it to set up the environment for the test. You can use setUp() to instantiate a new Intent object with the action ACTION_MAIN. You can then use this intent to start the Activity under test.

  Note: If you override this method, call super.setUp() as the first statement in your code.

• tearDown(): This method is invoked after all the test methods in the class. Use it to do garbage collection and re-setting before moving on to the next set of tests.

  Note: If you override this method, you must call super.tearDown() as the last statement in your code.

Another useful convention is to add the method testPreConditions() to your test class. Use this method to test that the application under test is initialized correctly. If this test fails, you know that that the initial conditions were in error. When this happens, further test results are suspect, regardless of whether or not the tests succeeded.

The Resources tab contains an Activity Testing tutorial with more information about creating test classes and methods.

Running Tests

When you run a test application in Eclipse with ADT, the output appears in an Eclipse view panel. You can run the entire test application, one class, or one method of a class. To do this, Eclipse runs the adb command for running a test application, and displays the output, so there is no difference between running tests inside Eclipse and running them from the command line.

As with any other application, to run a test application in Eclipse with ADT you must either attach a device to your computer or use the Android emulator. If you use the emulator, you must have an Android Virtual Device (AVD) that uses the same target

To run a test in Eclipse, you have two choices:

1. Run a test just as you run an application, by selecting Run As... > Android JUnit Test from the project's context menu or from the main menu's Run item.
2. Create an Eclipse run configuration for your test project. This is useful if you want multiple test suites, each consisting of selected tests from the project. To run a test suite, you run the test configuration.

   Creating and running test configurations is described in the next section.

To create and run a test suite using a run configuration:

1. In the Package Explorer, select the test project, then from the main menu, select Run > Run Configurations.... The Run Configurations dialog appears.
2. In the left-hand pane, find the Android JUnit Test entry. In the right-hand pane, click the Test tab. The Name: text box shows the name of your project. The Test class: dropdown box shows one your project's classes test classes in your project.
3. To run one test class, click Run a single test, then enter your project name in the Project: text box and the class name in the Test class: text box.

   To run all the test classes, click Run all tests in the selected project or package, then enter the project or package name in the text box.

4. Now click the Target tab.
   • Optional: If you are using the emulator, click Automatic, then in the Android Virtual Device (AVD) selection table, select an existing AVD.
   • In the Emulator Launch Parameters pane, set the Android emulator flags you want to use. These are documented in the topic Emulator Startup Options.
5. Click the Common tab. In the Save As pane, click Local to save this run configuration locally, or click Shared to save it to another project.
6. Optional: Add the configuration to the Run toolbar and the Favorites menu: in the Display in Favorites pane click the checkbox next to Run.
7. Optional: To add this configuration to the Debug menu and toolbar, click the checkbox next to Debug.
8. To save your settings, click Close.
   

   Note: Although you can run the test immediately by clicking Run, you should save the test first and then run it by selecting it from the Eclipse standard toolbar.

9. On the Eclipse standard toolbar, click the down arrow next to the green Run arrow. This displays a menu of saved Run and Debug configurations.
10. Select the test run configuration you just created.
11. The progress of your test appears in the Console view. You should see the following messages, among others:
    • Performing Android.test.InstrumentationTestRunner JUnit launch
      The class name that proceeds "JUnit" depends on the Android instrumentation class you have chosen.
    • If you are using an emulator and you have not yet started it, then you will see the message:

      Automatic Target Mode: launching new emulator with compatible AVD avdname
      (where avdname is the name of the AVD you are using.)

    • If you have not already installed your test application, then you will see the message:

      Uploading testclass.apk onto device 'device-id'
      where testclass is the name of your unit test class and device-id is the name and port for your test device or emulator, followed by the message Installing testclass.apk

    • Launching instrumentation Android.test.InstrumentationTestRunner on device device-id.
      This indicates that Android's Instrumentation system is now testing your code. Again, the instrumentation class name depends on the Android instrumentation class you have chosen.
    • Test run complete.
      When you see this, your unit tests have finished.

The test results appear in the JUnit view. This is divided into an upper summary pane, and a lower stack trace pane.

The upper pane contains test information. In the pane's header, you see the following information:

• Total time elapsed for the test application (labeled Finished after x seconds).
• Number of runs (Runs:) - the number of tests in the entire test class.
• Number of errors (Errors:) - the number of program errors and exceptions encountered during the test run.
• Number of failures (Failures:) - the number of test failures encountered during the test run. This is the number of assertion failures. A test can fail even if the program does not encounter an error.
• A progress bar. The progress bar extends from left to right as the tests run. If all the tests succeed, the bar remains green. If a test fails, the bar turns from green to red.

The body of the upper pane contains the details of the test run. For each test case class that was run, you see a line with the class name. To look at the results for the individual test methods in that class, you click the left arrow to expand the line. You now see a line for each test method in the class, and to its right the time it took to run. If you double-click the method name, Eclipse opens the test class source in an editor view pane and moves the focus to the first line of the test method.

The lower pane is for stack traces. If you highlight a failed test in the upper pane, the lower pane contains a stack trace for the test. If a line corresponds to a point in your test code, you can double-click it to display the code in an editor view pane, with the line highlighted. For a successful test, the lower pane is empty.