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1page.title=Testing Fundamentals
2parent.title=Testing
3parent.link=index.html
4@jd:body
5
6<div id="qv-wrapper">
7  <div id="qv">
8  <h2>In this document</h2>
9  <ol>
10    <li>
11        <a href="#TestStructure">Test Structure</a>
12    </li>
13    <li>
14        <a href="#TestProjects">Test Projects</a>
15    </li>
16    <li>
17      <a href="#TestAPI">The Testing API</a>
18      <ol>
19        <li>
20          <a href="#JUnit">JUnit</a>
21        </li>
22        <li>
23          <a href="#Instrumentation">Instrumentation</a>
24        </li>
25        <li>
26            <a href="#TestCaseClasses">Test case classes</a>
27        </li>
28        <li>
29          <a href="#AssertionClasses">Assertion classes</a>
30        </li>
31        <li>
32          <a href="#MockObjectClasses">Mock object classes</a>
33        </li>
34      </ol>
35    </li>
36    <li>
37        <a href="#InstrumentationTestRunner">Running Tests</a>
38    </li>
39    <li>
40        <a href="#TestResults">Seeing Test Results</a>
41    </li>
42    <li>
43        <a href="#Monkeys">monkey and monkeyrunner</a>
44    </li>
45    <li>
46       <a href="#PackageNames">Working With Package Names</a>
47    </li>
48    <li>
49        <a href="#WhatToTest">What To Test</a>
50    </li>
51    <li>
52        <a href="#NextSteps">Next Steps</a>
53    </li>
54  </ol>
55  <h2>Key classes</h2>
56    <ol>
57      <li>{@link android.test.InstrumentationTestRunner}</li>
58      <li>{@link android.test}</li>
59      <li>{@link android.test.mock}</li>
60      <li>{@link junit.framework}</li>
61    </ol>
62  <h2>Related tutorials</h2>
63    <ol>
64        <li>
65            <a href="{@docRoot}tools/testing/activity_test.html">Activity Testing Tutorial</a>
66        </li>
67    </ol>
68  <h2>See also</h2>
69      <ol>
70        <li>
71          <a href="{@docRoot}tools/testing/testing_eclipse.html">
72          Testing from Eclipse with ADT</a>
73        </li>
74        <li>
75          <a href="{@docRoot}tools/testing/testing_otheride.html">
76          Testing from Other IDEs</a>
77        </li>
78        <li>
79          <a href="{@docRoot}tools/help/monkeyrunner_concepts.html">
80          monkeyrunner</a>
81        </li>
82        <li>
83     <a href="{@docRoot}tools/help/monkey.html">UI/Application Exerciser Monkey</a>
84        </li>
85      </ol>
86  </div>
87</div>
88<p>
89    The Android testing framework, an integral part of the development environment,
90    provides an architecture and powerful tools that help you test every aspect of your application
91    at every level from unit to framework.
92</p>
93<p>
94    The testing framework has these key features:
95</p>
96<ul>
97    <li>
98        Android test suites are based on JUnit. You can use plain JUnit to test a class that doesn't
99        call the Android API, or Android's JUnit extensions to test Android components. If you're
100        new to Android testing, you can start with general-purpose test case classes such as {@link
101        android.test.AndroidTestCase} and then go on to use more sophisticated classes.
102    </li>
103    <li>
104        The Android JUnit extensions provide component-specific test case classes. These classes
105        provide helper methods for creating mock objects and methods that help you control the
106        lifecycle of a component.
107    </li>
108    <li>
109        Test suites are contained in test packages that are similar to main application packages, so
110        you don't need to learn a new set of tools or techniques for designing and building tests.
111    </li>
112    <li>
113        The SDK tools for building and tests are available in Eclipse with ADT, and also in
114        command-line form for use with other IDEs. These tools get information from the project of
115        the application under test and use this information to automatically create the build files,
116        manifest file, and directory structure for the test package.
117    </li>
118    <li>
119        The SDK also provides
120  <a href="{@docRoot}tools/help/monkeyrunner_concepts.html">monkeyrunner</a>, an API
121        for testing devices with Python programs, and <a
122        href="{@docRoot}tools/help/monkey.html">UI/Application Exerciser Monkey</a>,
123        a command-line tool for stress-testing UIs by sending pseudo-random events to a device.
124    </li>
125</ul>
126<p>
127    This document describes the fundamentals of the Android testing framework, including the
128    structure of tests, the APIs that you use to develop tests, and the tools that you use to run
129    tests and view results. The document assumes you have a basic knowledge of Android application
130    programming and JUnit testing methodology.
131</p>
132<p>
133    The following diagram summarizes the testing framework:
134</p>
135<div style="width: 70%; margin-left:auto; margin-right:auto;">
136<a href="{@docRoot}images/testing/test_framework.png">
137    <img src="{@docRoot}images/testing/test_framework.png"
138        alt="The Android testing framework"/>
139</a>
140</div>
141<h2 id="TestStructure">Test Structure</h2>
142<p>
143    Android's build and test tools assume that test projects are organized into a standard
144    structure of tests, test case classes, test packages, and test projects.
145</p>
146<p>
147    Android testing is based on JUnit. In general, a JUnit test is a method whose
148    statements test a part of the application under test. You organize test methods into classes
149    called test cases (or test suites). Each test is an isolated test of an individual module in
150    the application under test. Each class is a container for related test methods, although it
151    often provides helper methods as well.
152</p>
153<p>
154    In JUnit, you build one or more test source files into a class file. Similarly, in Android you
155    use the SDK's build tools to build one or more test source files into class files in an
156    Android test package. In JUnit, you use a test runner to execute test classes. In Android, you
157    use test tools to load the test package and the application under test, and the tools then
158    execute an Android-specific test runner.
159</p>
160<h2 id="TestProjects">Test Projects</h2>
161<p>
162    Tests, like Android applications, are organized into projects.
163</p>
164<p>
165    A test project is a directory or Eclipse project in which you create the source code, manifest
166    file, and other files for a test package. The Android SDK contains tools for Eclipse with ADT
167    and for the command line that create and update test projects for you. The tools create the
168    directories you use for source code and resources and the manifest file for the test package.
169    The command-line tools also create the Ant build files you need.
170</p>
171<p>
172    You should always use Android tools to create a test project. Among other benefits,
173    the tools:
174</p>
175    <ul>
176        <li>
177            Automatically set up your test package to use
178            {@link android.test.InstrumentationTestRunner} as the test case runner. You must use
179            <code>InstrumentationTestRunner</code> (or a subclass) to run JUnit tests.
180        </li>
181        <li>
182            Create an appropriate name for the test package. If the application
183            under test has a package name of <code>com.mydomain.myapp</code>, then the
184            Android tools set the test package name to <code>com.mydomain.myapp.test</code>. This
185            helps you identify their relationship, while preventing conflicts within the system.
186        </li>
187        <li>
188            Automatically create the proper build files, manifest file, and directory
189            structure for the test project. This helps you to build the test package without
190            having to modify build files and sets up the linkage between your test package and
191            the application under test.
192            The
193        </li>
194    </ul>
195<p>
196    You can create a test project anywhere in your file system, but the best approach is to
197    add the test project so that its root directory <code>tests/</code> is at the same level
198    as the <code>src/</code> directory of the main application's project. This helps you find the
199    tests associated with an application. For example, if your application project's root directory
200    is <code>MyProject</code>, then you should use the following directory structure:
201</p>
202<pre class="classic no-pretty-print">
203  MyProject/
204      AndroidManifest.xml
205      res/
206          ... (resources for main application)
207      src/
208          ... (source code for main application) ...
209      tests/
210          AndroidManifest.xml
211          res/
212              ... (resources for tests)
213          src/
214              ... (source code for tests)
215</pre>
216<h2 id="TestAPI">The Testing API</h2>
217<p>
218    The Android testing API is based on the JUnit API and extended with a instrumentation
219    framework and Android-specific testing classes.
220</p>
221<h3 id="JUnit">JUnit</h3>
222<p>
223    You can use the JUnit {@link junit.framework.TestCase TestCase} class to do unit testing on
224    a class that doesn't call Android APIs. <code>TestCase</code> is also the base class for
225    {@link android.test.AndroidTestCase}, which you can use to test Android-dependent objects.
226    Besides providing the JUnit framework, AndroidTestCase offers Android-specific setup,
227    teardown, and helper methods.
228</p>
229<p>
230    You use the JUnit {@link junit.framework.Assert} class to display test results.
231    The assert methods compare values you expect from a test to the actual results and
232    throw an exception if the comparison fails. Android also provides a class of assertions that
233    extend the possible types of comparisons, and another class of assertions for testing the UI.
234    These are described in more detail in the section <a href="#AssertionClasses">
235    Assertion classes</a>
236</p>
237<p>
238    To learn more about JUnit, you can read the documentation on the
239    <a href="http://www.junit.org">junit.org</a> home page.
240    Note that the Android testing API supports JUnit 3 code style, but not JUnit 4. Also, you must
241    use Android's instrumented test runner {@link android.test.InstrumentationTestRunner} to run
242    your test case classes. This test runner is described in the
243    section <a href="#InstrumentationTestRunner">Running Tests</a>.
244</p>
245<h3 id="Instrumentation">Instrumentation</h3>
246<p>
247    Android instrumentation is a set of control methods or "hooks" in the Android system. These hooks
248    control an Android component independently of its normal lifecycle. They also control how
249    Android loads applications.
250</p>
251<p>
252    Normally, an Android component runs in a lifecycle determined by the system. For example, an
253    Activity object's lifecycle starts when the Activity is activated by an Intent. The object's
254    <code>onCreate()</code> method is called, followed by <code>onResume()</code>. When the user
255    starts another application, the <code>onPause()</code> method is called. If the Activity
256    code calls the <code>finish()</code> method, the <code>onDestroy()</code> method is called.
257    The Android framework API does not provide a way for your code to invoke these callback
258    methods directly, but you can do so using instrumentation.
259</p>
260<p>
261    Also, the system runs all the components of an application into the same
262    process. You can allow some components, such as content providers, to run in a separate process,
263    but you can't force an application to run in the same process as another application that is
264    already running.
265</p>
266<p>
267    With Android instrumentation, though, you can invoke callback methods in your test code.
268    This allows you to run through the lifecycle of a component step by step, as if you were
269    debugging the component. The following test code snippet demonstrates how to use this to
270    test that an Activity saves and restores its state:
271</p>
272<a name="ActivitySnippet"></a>
273<pre>
274    // Start the main activity of the application under test
275    mActivity = getActivity();
276
277    // Get a handle to the Activity object's main UI widget, a Spinner
278    mSpinner = (Spinner)mActivity.findViewById(com.android.example.spinner.R.id.Spinner01);
279
280    // Set the Spinner to a known position
281    mActivity.setSpinnerPosition(TEST_STATE_DESTROY_POSITION);
282
283    // Stop the activity - The onDestroy() method should save the state of the Spinner
284    mActivity.finish();
285
286    // Re-start the Activity - the onResume() method should restore the state of the Spinner
287    mActivity = getActivity();
288
289    // Get the Spinner's current position
290    int currentPosition = mActivity.getSpinnerPosition();
291
292    // Assert that the current position is the same as the starting position
293    assertEquals(TEST_STATE_DESTROY_POSITION, currentPosition);
294</pre>
295<p>
296    The key method used here is
297    {@link android.test.ActivityInstrumentationTestCase2#getActivity()}, which is a
298    part of the instrumentation API. The Activity under test is not started until you call this
299    method. You can set up the test fixture in advance, and then call this method to start the
300    Activity.
301</p>
302<p>
303    Also, instrumentation can load both a test package and the application under test into the
304    same process. Since the application components and their tests are in the same process, the
305    tests can invoke methods in the components, and modify and examine fields in the components.
306</p>
307<h3 id="TestCaseClasses">Test case classes</h3>
308<p>
309    Android provides several test case classes that extend {@link junit.framework.TestCase} and
310    {@link junit.framework.Assert} with Android-specific setup, teardown, and helper methods.
311</p>
312<h4 id="AndroidTestCase">AndroidTestCase</h4>
313<p>
314    A useful general test case class, especially if you are
315    just starting out with Android testing, is {@link android.test.AndroidTestCase}. It extends
316    both {@link junit.framework.TestCase} and {@link junit.framework.Assert}. It provides the
317    JUnit-standard <code>setUp()</code> and <code>tearDown()</code> methods, as well as
318    all of JUnit's Assert methods. In addition, it provides methods for testing permissions, and a
319    method that guards against memory leaks by clearing out certain class references.
320</p>
321<h4 id="ComponentTestCase">Component-specific test cases</h4>
322<p>
323    A key feature of the Android testing framework is its component-specific test case classes.
324    These address specific component testing needs with methods for fixture setup and
325    teardown and component lifecycle control. They also provide methods for setting up mock objects.
326    These classes are described in the component-specific testing topics:
327</p>
328<ul>
329    <li>
330        <a href="{@docRoot}tools/testing/activity_testing.html">Activity Testing</a>
331    </li>
332    <li>
333        <a href="{@docRoot}tools/testing/contentprovider_testing.html">
334        Content Provider Testing</a>
335    </li>
336    <li>
337        <a href="{@docRoot}tools/testing/service_testing.html">Service Testing</a>
338    </li>
339</ul>
340<p>
341    Android does not provide a separate test case class for BroadcastReceiver. Instead, test a
342    BroadcastReceiver by testing the component that sends it Intent objects, to verify that the
343    BroadcastReceiver responds correctly.
344</p>
345<h4 id="ApplicationTestCase">ApplicationTestCase</h4>
346<p>
347    You use the {@link android.test.ApplicationTestCase} test case class to test the setup and
348    teardown of {@link android.app.Application} objects. These objects maintain the global state of
349    information that applies to all the components in an application package. The test case can
350    be useful in verifying that the &lt;application&gt; element in the manifest file is correctly
351    set up. Note, however, that this test case does not allow you to control testing of the
352    components within your application package.
353</p>
354<h4 id="InstrumentationTestCase">InstrumentationTestCase</h4>
355<p>
356    If you want to use instrumentation methods in a test case class, you must use
357    {@link android.test.InstrumentationTestCase} or one of its subclasses. The
358    {@link android.app.Activity} test cases extend this base class with other functionality that
359    assists in Activity testing.
360</p>
361
362<h3 id="AssertionClasses">Assertion classes</h3>
363<p>
364    Because Android test case classes extend JUnit, you can use assertion methods to display the
365    results of tests. An assertion method compares an actual value returned by a test to an
366    expected value, and throws an AssertionException if the comparison test fails. Using assertions
367    is more convenient than doing logging, and provides better test performance.
368</p>
369<p>
370    Besides the JUnit {@link junit.framework.Assert} class methods, the testing API also provides
371    the {@link android.test.MoreAsserts} and {@link android.test.ViewAsserts} classes:
372</p>
373<ul>
374    <li>
375        {@link android.test.MoreAsserts} contains more powerful assertions such as
376        {@link android.test.MoreAsserts#assertContainsRegex}, which does regular expression
377        matching.
378    </li>
379    <li>
380        {@link android.test.ViewAsserts} contains useful assertions about Views. For example
381        it contains {@link android.test.ViewAsserts#assertHasScreenCoordinates} that tests if a View
382        has a particular X and Y position on the visible screen. These asserts simplify testing of
383        geometry and alignment in the UI.
384    </li>
385</ul>
386<h3 id="MockObjectClasses">Mock object classes</h3>
387<p>
388    To facilitate dependency injection in testing, Android provides classes that create mock system
389    objects such as {@link android.content.Context} objects,
390    {@link android.content.ContentProvider} objects, {@link android.content.ContentResolver}
391    objects, and {@link android.app.Service} objects. Some test cases also provide mock
392    {@link android.content.Intent} objects. You use these mocks both to isolate tests
393    from the rest of the system and to facilitate dependency injection for testing. These classes
394    are found in the packages {@link android.test} and {@link android.test.mock}.
395</p>
396<p>
397    Mock objects isolate tests from a running system by stubbing out or overriding
398    normal operations. For example, a {@link android.test.mock.MockContentResolver}
399    replaces the normal resolver framework with its own local framework, which is isolated
400    from the rest of the system. MockContentResolver also stubs out the
401    {@link android.content.ContentResolver#notifyChange(Uri, ContentObserver, boolean)} method
402    so that observer objects outside the test environment are not accidentally triggered.
403</p>
404<p>
405    Mock object classes also facilitate dependency injection by providing a subclass of the
406    normal object that is non-functional except for overrides you define. For example, the
407    {@link android.test.mock.MockResources} object provides a subclass of
408    {@link android.content.res.Resources} in which all the methods throw Exceptions when called.
409    To use it, you override only those methods that must provide information.
410</p>
411<p>
412    These are the mock object classes available in Android:
413</p>
414<h4 id="SimpleMocks">Simple mock object classes</h4>
415<p>
416    {@link android.test.mock.MockApplication}, {@link android.test.mock.MockContext},
417    {@link android.test.mock.MockContentProvider}, {@link android.test.mock.MockCursor},
418    {@link android.test.mock.MockDialogInterface}, {@link android.test.mock.MockPackageManager}, and
419    {@link android.test.mock.MockResources} provide a simple and useful mock strategy. They are
420    stubbed-out versions of the corresponding system object class, and all of their methods throw an
421    {@link java.lang.UnsupportedOperationException} exception if called. To use them, you override
422    the methods you need in order to provide mock dependencies.
423</p>
424<p class="Note"><strong>Note:</strong>
425    {@link android.test.mock.MockContentProvider}
426    and {@link android.test.mock.MockCursor} are new as of API level 8.
427</p>
428<h4 id="ResolverMocks">Resolver mock objects</h4>
429<p>
430    {@link android.test.mock.MockContentResolver} provides isolated testing of content providers by
431    masking out the normal system resolver framework. Instead of looking in the system to find a
432    content provider given an authority string, MockContentResolver uses its own internal table. You
433    must explicitly add providers to this table using
434    {@link android.test.mock.MockContentResolver#addProvider(String,ContentProvider)}.
435</p>
436<p>
437    With this feature, you can associate a mock content provider with an authority. You can create
438    an instance of a real provider but use test data in it. You can even set the provider for an
439    authority to <code>null</code>. In effect, a MockContentResolver object isolates your test
440    from providers that contain real data. You can control the
441    function of the provider, and you can prevent your test from affecting real data.
442</p>
443<h3 id="ContextMocks">Contexts for testing</h3>
444<p>
445    Android provides two Context classes that are useful for testing:
446</p>
447<ul>
448    <li>
449        {@link android.test.IsolatedContext} provides an isolated {@link android.content.Context},
450        File, directory, and database operations that use this Context take place in a test area.
451        Though its functionality is limited, this Context has enough stub code to respond to
452        system calls.
453        <p>
454            This class allows you to test an application's data operations without affecting real
455            data that may be present on the device.
456        </p>
457    </li>
458    <li>
459        {@link android.test.RenamingDelegatingContext} provides a Context in which
460        most functions are handled by an existing {@link android.content.Context}, but
461        file and database operations are handled by a {@link android.test.IsolatedContext}.
462        The isolated part uses a test directory and creates special file and directory names.
463        You can control the naming yourself, or let the constructor determine it automatically.
464        <p>
465            This object provides a quick way to set up an isolated area for data operations,
466            while keeping normal functionality for all other Context operations.
467        </p>
468    </li>
469</ul>
470<h2 id="InstrumentationTestRunner">Running Tests</h2>
471<p>
472    Test cases are run by a test runner class that loads the test case class, set ups,
473    runs, and tears down each test. An Android test runner must also be instrumented, so that
474    the system utility for starting applications can control how the test package
475    loads test cases and the application under test. You tell the Android platform
476    which instrumented test runner to use by setting a value in the test package's manifest file.
477</p>
478<p>
479    {@link android.test.InstrumentationTestRunner} is the primary Android test runner class. It
480    extends the JUnit test runner framework and is also instrumented. It can run any of the test
481    case classes provided by Android and supports all possible types of testing.
482</p>
483<p>
484    You specify <code>InstrumentationTestRunner</code> or a subclass in your test package's
485    manifest file, in the
486<code><a href="{@docRoot}guide/topics/manifest/instrumentation-element.html">&lt;instrumentation&gt;</a></code>
487    element. Also, <code>InstrumentationTestRunner</code> code resides
488    in the shared library <code>android.test.runner</code>,  which is not normally linked to
489    Android code. To include it, you must specify it in a
490<code><a href="{@docRoot}guide/topics/manifest/uses-library-element.html">&lt;uses-library&gt;</a></code>
491    element. You do not have to set up these elements yourself. Both Eclipse with ADT and the
492    <code>android</code> command-line tool construct them automatically and add them to your
493    test package's manifest file.
494</p>
495<p class="Note">
496    <strong>Note:</strong> If you use a test runner other than
497    <code>InstrumentationTestRunner</code>, you must change the &lt;instrumentation&gt;
498    element to point to the class you want to use.
499</p>
500<p>
501    To run {@link android.test.InstrumentationTestRunner}, you use internal system classes called by
502    Android tools. When you run a test in Eclipse with ADT, the classes are called automatically.
503    When you run a test from the command line, you run these classes with
504    <a href="{@docRoot}tools/help/adb.html">Android Debug Bridge (adb)</a>.
505</p>
506<p>
507    The system classes load and start the test package, kill any processes that
508    are running an instance of the application under test, and then load a new instance of the
509    application under test. They then pass control to
510    {@link android.test.InstrumentationTestRunner}, which runs
511    each test case class in the test package. You can also control which test cases and
512    methods are run using settings in Eclipse with ADT, or using flags with the command-line tools.
513</p>
514<p>
515    Neither the system classes nor {@link android.test.InstrumentationTestRunner} run
516    the application under test. Instead, the test case does this directly. It either calls methods
517    in the application under test, or it calls its own methods that trigger lifecycle events in
518    the application under test. The application is under the complete control of the test case,
519    which allows it to set up the test environment (the test fixture) before running a test. This
520    is demonstrated in the previous <a href="#ActivitySnippet">code snippet</a> that tests an
521    Activity that displays a Spinner widget.
522</p>
523<p>
524    To learn more about running tests, please read the topics
525    <a href="{@docRoot}tools/testing/testing_eclipse.html">
526    Testing from Eclipse with ADT</a> or
527    <a href="{@docRoot}tools/testing/testing_otheride.html">
528    Testing from Other IDEs</a>.
529</p>
530<h2 id="TestResults">Seeing Test Results</h2>
531<p>
532    The Android testing framework returns test results back to the tool that started the test.
533    If you run a test in Eclipse with ADT, the results are displayed in a new JUnit view pane. If
534    you run a test from the command line, the results are displayed in <code>STDOUT</code>. In
535    both cases, you see a test summary that displays the name of each test case and method that
536    was run. You also see all the assertion failures that occurred. These include pointers to the
537    line in the test code where the failure occurred. Assertion failures also list the expected
538    value and actual value.
539</p>
540<p>
541    The test results have a format that is specific to the IDE that you are using. The test
542    results format for Eclipse with ADT is described in
543    <a href="{@docRoot}tools/testing/testing_eclipse.html#RunTestEclipse">
544    Testing from Eclipse with ADT</a>. The test results format for tests run from the
545    command line is described in
546    <a href="{@docRoot}tools/testing/testing_otheride.html#RunTestsCommand">
547    Testing from Other IDEs</a>.
548</p>
549<h2 id="Monkeys">monkey and monkeyrunner</h2>
550<p>
551    The SDK provides two tools for functional-level application testing:
552</p>
553    <ul>
554        <li>
555The <a href="{@docRoot}tools/help/monkey.html">UI/Application Exerciser Monkey</a>,
556            usually called "monkey", is a command-line tool that sends pseudo-random streams of
557            keystrokes, touches, and gestures to a device. You run it with the
558            <a href="{@docRoot}tools/help/adb.html">Android Debug Bridge</a> (adb) tool.
559            You use it to stress-test your application and report back errors that are encountered.
560            You can repeat a stream of events by running the tool each time with the same random
561            number seed.
562        </li>
563        <li>
564    The <a href="{@docRoot}tools/help/monkeyrunner_concepts.html">monkeyrunner</a> tool
565            is an API and execution environment for test programs written in Python. The API
566            includes functions for connecting to a device, installing and uninstalling packages,
567            taking screenshots, comparing two images, and running a test package against an
568            application. Using the API, you can write a wide range of large, powerful, and complex
569            tests. You run programs that use the API with the <code>monkeyrunner</code> command-line
570            tool.
571        </li>
572    </ul>
573<h2 id="PackageNames">Working With Package names</h2>
574<p>
575    In the test environment, you work with both Android application package names and
576    Java package identifiers. Both use the same naming format, but they represent substantially
577    different entities. You need to know the difference to set up your tests correctly.
578</p>
579<p>
580    An Android package name is a unique system name for a <code>.apk</code> file, set by the
581    &quot;android:package&quot; attribute of the &lt;manifest&gt; element in the package's
582    manifest. The Android package name of your test package must be different from the
583    Android package name of the application under test. By default, Android tools create the
584    test package name by appending ".test" to the package name of the application under test.
585</p>
586<p>
587    The test package also uses an Android package name to target the application package it
588    tests. This is set in the &quot;android:targetPackage&quot; attribute of the
589    &lt;instrumentation&gt; element in the test package's manifest.
590</p>
591<p>
592    A Java package identifier applies to a source file. This package name reflects the directory
593    path of the source file. It also affects the visibility of classes and members to each other.
594</p>
595<p>
596    Android tools that create test projects set up an Android test package name for you.
597    From your input, the tools set up the test package name and the target package name for the
598    application under test. For these tools to work, the application project must already exist.
599</p>
600<p>
601    By default, these tools set the Java package identifier for the test class to be the same
602    as the Android package identifier. You may want to change this if you want to expose
603    members in the application under test by giving them package visibility. If you do this,
604    change only the Java package identifier, not the Android package names, and change only the
605    test case source files. Do not change the Java package name of the generated
606    <code>R.java</code> class in your test package, because it will then conflict with the
607    <code>R.java</code> class in the application under test. Do not change the Android package name
608    of your test package to be the same as the application it tests, because then their names
609    will no longer be unique in the system.
610</p>
611<h2 id="WhatToTest">What to Test</h2>
612<p>
613    The topic <a href="{@docRoot}tools/testing/what_to_test.html">What To Test</a>
614    describes the key functionality you should test in an Android application, and the key
615    situations that might affect that functionality.
616</p>
617<p>
618    Most unit testing is specific to the Android component you are testing.
619    The topics <a href="{@docRoot}tools/testing/activity_testing.html">Activity Testing</a>,
620    <a href="{@docRoot}tools/testing/contentprovider_testing.html">
621    Content Provider Testing</a>, and <a href="{@docRoot}tools/testing/service_testing.html">
622    Service Testing</a> each have a section entitled "What To Test" that lists possible testing
623    areas.
624</p>
625<p>
626    When possible, you should run these tests on an actual device. If this is not possible, you can
627    use the <a href="{@docRoot}tools/devices/emulator.html">Android Emulator</a> with
628    Android Virtual Devices configured for the hardware, screens, and versions you want to test.
629</p>
630<h2 id="NextSteps">Next Steps</h2>
631<p>
632    To learn how to set up and run tests in Eclipse, please refer to
633<a href="{@docRoot}tools/testing/testing_eclipse.html">Testing from Eclipse with ADT</a>.
634    If you're not working in Eclipse, refer to
635<a href="{@docRoot}tools/testing/testing_otheride.html">Testing from Other IDEs</a>.
636</p>
637<p>
638    If you want a step-by-step introduction to Android testing, try the
639    <a href="{@docRoot}tools/testing/activity_test.html">Activity Testing Tutorial</a>.
640</p>
641