docs/html/tools/testing/activity_testing.jd

page.title=Activity Testing
parent.title=Testing
parent.link=index.html
@jd:body

<div id="qv-wrapper">
  <div id="qv">
  <h2>In this document</h2>
  <ol>
    <li>
      <a href="#ActivityTestAPI">The Activity Testing API</a>
      <ol>
        <li>
            <a href="#ActivityInstrumentationTestCase2">ActivityInstrumentationTestCase2</a>
        </li>
        <li>
            <a href="#ActivityUnitTestCase">ActivityUnitTestCase</a>
        </li>
        <li>
            <a href="#SingleLaunchActivityTestCase">SingleLaunchActivityTestCase</a>
        </li>
        <li>
            <a href="#MockObjectNotes">Mock objects and activity testing</a>
        </li>
        <li>
            <a href="#AssertionNotes">Assertions for activity testing</a>
        </li>
      </ol>
    </li>
    <li>
        <a href="#WhatToTest">What to Test</a>
    </li>
    <li>
        <a href="#NextSteps">Next Steps</a>
    </li>
    <li>
      <a href="#UITesting">Appendix: UI Testing Notes</a>
      <ol>
        <li>
          <a href="#RunOnUIThread">Testing on the UI thread</a>
        </li>
        <li>
          <a href="#NotouchMode">Turning off touch mode</a>
        </li>
        <li>
          <a href="#UnlockDevice">Unlocking the Emulator or Device</a>
        </li>
        <li>
          <a href="#UITestTroubleshooting">Troubleshooting UI tests</a>
        </li>
      </ol>
    </li>
    </ol>
<h2>Key Classes</h2>
    <ol>
      <li>{@link android.test.InstrumentationTestRunner}</li>
      <li>{@link android.test.ActivityInstrumentationTestCase2}</li>
      <li>{@link android.test.ActivityUnitTestCase}</li>
    </ol>
<h2>Related Tutorials</h2>
    <ol>
      <li>
         <a href="{@docRoot}tools/testing/activity_test.html">Activity Testing Tutorial</a>
      </li>
    </ol>
<h2>See Also</h2>
      <ol>
        <li>
          <a href="{@docRoot}tools/testing/testing_eclipse.html">
          Testing from Eclipse with ADT</a>
        </li>
        <li>
          <a href="{@docRoot}tools/testing/testing_otheride.html">
          Testing from Other IDEs</a>
        </li>
      </ol>
  </div>
</div>
<p>
    Activity testing is particularly dependent on the Android instrumentation framework.
    Unlike other components, activities have a complex lifecycle based on callback methods; these
    can't be invoked directly except by instrumentation. Also, the only way to send events to the
    user interface from a program is through instrumentation.
</p>
<p>
    This document describes how to test activities using instrumentation and other test
    facilities. The document assumes you have already read
    <a href="{@docRoot}tools/testing/testing_android.html">Testing Fundamentals</a>,
    the introduction to the Android testing and instrumentation framework.
</p>
<h2 id="ActivityTestAPI">The Activity Testing API</h2>
<p>
    The activity testing API base class is {@link android.test.InstrumentationTestCase},
    which provides instrumentation to the test case subclasses you use for Activities.
</p>
<p>
    For activity testing, this base class provides these functions:
</p>
<ul>
    <li>
        Lifecycle control: With instrumentation, you can start the activity under test, pause it,
        and destroy it, using methods provided by the test case classes.
    </li>
    <li>
        Dependency injection: Instrumentation allows you to create mock system objects such as
        Contexts or Applications and use them to run the activity under test. This
        helps you control the test environment and isolate it from production systems. You can
        also set up customized Intents and start an activity with them.
    </li>
    <li>
        User interface interaction: You use instrumentation to send keystrokes or touch events
        directly to the UI of the activity under test.
    </li>
</ul>
<p>
    The activity testing classes also provide the JUnit framework by extending
    {@link junit.framework.TestCase} and {@link junit.framework.Assert}.
</p>
<p>
    The two main testing subclasses are {@link android.test.ActivityInstrumentationTestCase2} and
    {@link android.test.ActivityUnitTestCase}. To test an Activity that is launched in a mode
    other than <code>standard</code>, you use {@link android.test.SingleLaunchActivityTestCase}.
</p>
<h3 id="ActivityInstrumentationTestCase2">ActivityInstrumentationTestCase2</h3>
<p>
    The {@link android.test.ActivityInstrumentationTestCase2} test case class is designed to do
    functional testing of one or more Activities in an application, using a normal system
    infrastructure. It runs the Activities in a normal instance of the application under test,
    using a standard system Context. It allows you to send mock Intents to the activity under
    test, so you can use it to test an activity that responds to multiple types of intents, or
    an activity that expects a certain type of data in the intent, or both. Notice, though, that it
    does not allow mock Contexts or Applications, so you can not isolate the test from the rest of
    a production system.
</p>
<h3 id="ActivityUnitTestCase">ActivityUnitTestCase</h3>
<p>
    The {@link android.test.ActivityUnitTestCase} test case class tests a single activity in
    isolation. Before you start the activity, you can inject a mock Context or Application, or both.
    You use it to run activity tests in isolation, and to do unit testing of methods
    that do not interact with Android. You can not send mock Intents to the activity under test,
    although you can call
    {@link android.app.Activity#startActivity(Intent) Activity.startActivity(Intent)} and then
    look at arguments that were received.
</p>
<h3 id="SingleLaunchActivityTestCase">SingleLaunchActivityTestCase</h3>
<p>
    The {@link android.test.SingleLaunchActivityTestCase} class is a convenience class for
    testing a single activity in an environment that doesn't change from test to test.
    It invokes {@link junit.framework.TestCase#setUp() setUp()} and
    {@link junit.framework.TestCase#tearDown() tearDown()} only once, instead of once per
    method call. It does not allow you to inject any mock objects.
</p>
<p>
    This test case is useful for testing an activity that runs in a mode other than
    <code>standard</code>. It ensures that the test fixture is not reset between tests. You
    can then test that the activity handles multiple calls correctly.
</p>
<h3 id="MockObjectNotes">Mock objects and activity testing</h3>
<p>
    This section contains notes about the use of the mock objects defined in
    {@link android.test.mock} with activity tests.
</p>
<p>
    The mock object {@link android.test.mock.MockApplication} is only available for activity
    testing if you use the {@link android.test.ActivityUnitTestCase} test case class.
    By default, <code>ActivityUnitTestCase</code>, creates a hidden <code>MockApplication</code>
    object that is used as the application under test. You can inject your own object using
    {@link android.test.ActivityUnitTestCase#setApplication(Application) setApplication()}.
</p>
<h3 id="AssertionNotes">Assertions for activity testing</h3>
<p>
    {@link android.test.ViewAsserts} defines assertions for Views. You use it to verify the
    alignment and position of View objects, and to look at the state of ViewGroup objects.
</p>
<h2 id="WhatToTest">What To Test</h2>
<ul>
    <li>
        Input validation: Test that an activity responds correctly to input values in an
        EditText View. Set up a keystroke sequence, send it to the activity, and then
        use {@link android.view.View#findViewById(int)} to examine the state of the View. You can
        verify that a valid keystroke sequence enables an OK button, while an invalid one leaves the
        button disabled. You can also verify that the Activity responds to invalid input by
        setting error messages in the View.
    </li>
    <li>
        Lifecycle events: Test that each of your application's activities handles lifecycle events
        correctly. In general, lifecycle events are actions, either from the system or from the
        user, that trigger a callback method such as <code>onCreate()</code> or
        <code>onClick()</code>. For example, an activity should respond to pause or destroy events
        by saving its state. Remember that even a change in screen orientation causes the current
        activity to be destroyed, so you should test that accidental device movements don't
        accidentally lose the application state.
    </li>
    <li>
        Intents: Test that each activity correctly handles the intents listed in the intent
        filter specified in its manifest. You can use
        {@link android.test.ActivityInstrumentationTestCase2} to send mock Intents to the
        activity under test.
    </li>
    <li>
        Runtime configuration changes: Test that each activity responds correctly to the
        possible changes in the device's configuration while your application is running. These
        include a change to the device's orientation, a change to the current language, and so
        forth. Handling these changes is described in detail in the topic
        <a href="{@docRoot}guide/topics/resources/runtime-changes.html">Handling Runtime
        Changes</a>.
    </li>
    <li>
        Screen sizes and resolutions: Before you publish your application, make sure to test it on
        all of the screen sizes and densities on which you want it to run. You can test the
        application on multiple sizes and densities using AVDs, or you can test your application
        directly on the devices that you are targeting. For more information, see the topic
        <a href="{@docRoot}guide/practices/screens_support.html">Supporting Multiple Screens</a>.
    </li>
</ul>
<h2 id="NextSteps">Next Steps</h2>
<p>
    To learn how to set up and run tests in Eclipse, please refer to 
<a href="{@docRoot}tools/testing/testing_eclipse.html">Testing from Eclipse with ADT</a>.
    If you're not working in Eclipse, refer to 
<a href="{@docRoot}tools/testing/testing_otheride.html">Testing from Other IDEs</a>.
</p>
<p>
    If you want a step-by-step introduction to testing activities, try the 
    <a href="{@docRoot}tools/testing/activity_test.html">Activity Testing Tutorial</a>, which
    guides you through a testing scenario that you develop against an activity-oriented application.
</p>
<h2 id="UITesting">Appendix: UI Testing Notes</h2>
<p>
    The following sections have tips for testing the UI of your Android application, specifically
    to help you handle actions that run in the UI thread, touch screen and keyboard events, and home
    screen unlock during testing.
</p>
<h3 id="RunOnUIThread">Testing on the UI thread</h3>
<p>
    An application's activities run on the application's <strong>UI thread</strong>. Once the
    UI is instantiated, for example in the activity's <code>onCreate()</code> method, then all
    interactions with the UI must run in the UI thread. When you run the application normally, it
    has access to the thread and does not have to do anything special.
</p>
<p>
    This changes when you run tests against the application. With instrumentation-based classes,
    you can invoke methods against the UI of the application under test. The other test classes
    don't allow this. To run an entire test method on the UI thread, you can annotate the thread
    with <code>@UiThreadTest</code>. Notice that this will run <em>all</em> of the method statements
    on the UI thread.  Methods that do not interact with the UI are not allowed; for example, you
    can't invoke <code>Instrumentation.waitForIdleSync()</code>.
</p>
<p>
    To run a subset of a test method on the UI thread, create an anonymous class of type
    <code>Runnable</code>, put the statements you want in the <code>run()</code> method, and
    instantiate a new instance of the class as a parameter to the method
    <code><em>appActivity</em>.runOnUiThread()</code>, where <code><em>appActivity</em></code> is
    the instance of the application you are testing.
</p>
<p>
    For example, this code instantiates an activity to test, requests focus (a UI action) for the
    Spinner displayed by the activity, and then sends a key to it. Notice that the calls to
    <code>waitForIdleSync</code> and <code>sendKeys</code> aren't allowed to run on the UI thread:
</p>
<pre>
  private MyActivity mActivity; // MyActivity is the class name of the app under test
  private Spinner mSpinner;

  ...

  protected void setUp() throws Exception {
      super.setUp();
      mInstrumentation = getInstrumentation();

      mActivity = getActivity(); // get a references to the app under test

      /*
       * Get a reference to the main widget of the app under test, a Spinner
       */
      mSpinner = (Spinner) mActivity.findViewById(com.android.demo.myactivity.R.id.Spinner01);

  ...

  public void aTest() {
      /*
       * request focus for the Spinner, so that the test can send key events to it
       * This request must be run on the UI thread. To do this, use the runOnUiThread method
       * and pass it a Runnable that contains a call to requestFocus on the Spinner.
       */
      mActivity.runOnUiThread(new Runnable() {
          public void run() {
              mSpinner.requestFocus();
          }
      });

      mInstrumentation.waitForIdleSync();

      this.sendKeys(KeyEvent.KEYCODE_DPAD_CENTER);
</pre>

<h3 id="NotouchMode">Turning off touch mode</h3>
<p>
    To control the emulator or a device with key events you send from your tests, you must turn off
    touch mode. If you do not do this, the key events are ignored.
</p>
<p>
    To turn off touch mode, you invoke
    <code>ActivityInstrumentationTestCase2.setActivityTouchMode(false)</code>
    <em>before</em> you call <code>getActivity()</code> to start the activity. You must invoke the
    method in a test method that is <em>not</em> running on the UI thread. For this reason, you
    can't invoke the touch mode method from a test method that is annotated with
    <code>@UIThread</code>. Instead, invoke the touch mode method from <code>setUp()</code>.
</p>
<h3 id="UnlockDevice">Unlocking the emulator or device</h3>
<p>
    You may find that UI tests don't work if the emulator's or device's home screen is disabled with
    the keyguard pattern. This is because the application under test can't receive key events sent
    by <code>sendKeys()</code>. The best way to avoid this is to start your emulator or device
    first and then disable the keyguard for the home screen.
</p>
<p>
    You can also explicitly disable the keyguard. To do this,
    you need to add a permission in the manifest file (<code>AndroidManifest.xml</code>) and
    then disable the keyguard in your application under test. Note, though, that you either have to
    remove this before you publish your application, or you have to disable it with code in
    the published application.
</p>
<p>
    To add the permission, add the element
    <code>&lt;uses-permission android:name="android.permission.DISABLE_KEYGUARD"/&gt;</code>
    as a child of the <code>&lt;manifest&gt;</code> element. To disable the KeyGuard, add the
    following code to the <code>onCreate()</code> method of activities you intend to test:
</p>
<pre>
  mKeyGuardManager = (KeyguardManager) getSystemService(KEYGUARD_SERVICE);
  mLock = mKeyGuardManager.newKeyguardLock("<em>activity_classname</em>");
  mLock.disableKeyguard();
</pre>
<p>where <code><em>activity_classname</em></code> is the class name of the activity.</p>
<h3 id="UITestTroubleshooting">Troubleshooting UI tests</h3>
<p>
    This section lists some of the common test failures you may encounter in UI testing, and their
    causes:
</p>
<dl>
    <dt><code>WrongThreadException</code></dt>
    <dd>
      <p><strong>Problem:</strong></p>
      For a failed test, the Failure Trace contains the following error message:
      <code>
        android.view.ViewRoot$CalledFromWrongThreadException: Only the original thread that created
        a view hierarchy can touch its views.
      </code>
      <p><strong>Probable Cause:</strong></p>
        This error is common if you tried to send UI events to the UI thread from outside the UI
        thread. This commonly happens if you send UI events from the test application, but you don't
        use the <code>@UIThread</code> annotation or the <code>runOnUiThread()</code> method. The
        test method tried to interact with the UI outside the UI thread.
      <p><strong>Suggested Resolution:</strong></p>
        Run the interaction on the UI thread. Use a test class that provides instrumentation. See
        the previous section <a href="#RunOnUIThread">Testing on the UI Thread</a>
        for more details.
    </dd>
    <dt><code>java.lang.RuntimeException</code></dt>
    <dd>
      <p><strong>Problem:</strong></p>
        For a failed test, the Failure Trace contains the following error message:
      <code>
        java.lang.RuntimeException: This method can not be called from the main application thread
      </code>
      <p><strong>Probable Cause:</strong></p>
        This error is common if your test method is annotated with <code>@UiThreadTest</code> but
        then tries to do something outside the UI thread or tries to invoke
        <code>runOnUiThread()</code>.
      <p><strong>Suggested Resolution:</strong></p>
        Remove the <code>@UiThreadTest</code> annotation, remove the <code>runOnUiThread()</code>
        call, or re-factor your tests.
    </dd>
</dl>