1 page.title=Creating Unit Tests 2 trainingnavtop=true 3 @jd:body 4 5 <!-- This is the training bar --> 6 <div id="tb-wrapper"> 7 <div id="tb"> 8 9 <h2>This lesson teaches you to</h2> 10 <ol> 11 <li><a href="#testcase">Create a Test Case for Activity Unit Testing</a> 12 <li><a href="#test_method">Validate Launch of Another Activity</a> 13 </ol> 14 15 <h2>Try it out</h2> 16 <div class="download-box"> 17 <a href="http://developer.android.com/shareables/training/AndroidTestingFun.zip" 18 class="button">Download the demo</a> 19 <p class="filename">AndroidTestingFun.zip</p> 20 </div> 21 22 </div> 23 </div> 24 25 <p>An {@link android.app.Activity} unit test is an excellent way to quickly 26 verify the state of an {@link android.app.Activity} and its interactions with 27 other components in isolation (that is, disconnected from the rest of the 28 system). A unit test generally tests the smallest possible unit of code 29 (which could be a method, class, or component), without dependencies on system 30 or network resources. For example, you can write a unit test to check 31 that an {@link android.app.Activity} has the correct layout or that it 32 triggers an {@link android.content.Intent} object correctly.</p> 33 <p>Unit tests are generally not suitable for testing complex UI interaction 34 events with the system. Instead, you should use 35 the {@link android.test.ActivityInstrumentationTestCase2} class, as described 36 in <a href="activity-ui-testing.html">Testing UI Components</a>.</p> 37 <p>This lesson shows how you can write a unit test to verify that an 38 {@link android.content.Intent} is triggered to launch another 39 {@link android.app.Activity}. 40 Since the test runs in an isolated environment, the 41 {@link android.content.Intent} 42 is not actually sent to the Android system, but you can inspect that the 43 {@link android.content.Intent} object's payload data is accurate.</p> 44 <p>For a complete test case example, take a look at 45 {@code LaunchActivityTest.java} in the sample app.</p> 46 47 <p class="note"><strong>Note: </strong>To test against system or external 48 dependencies, you can use mock objects from a mocking 49 framework and inject them into your unit tests. To learn more about the mocking 50 framework provided by Android, see 51 <a href="{@docRoot}tools/testing/testing_android.html#MockObjectClasses}">Mock 52 Object Classes</a>.</p> 53 54 <h2 id="testcase">Create a Test Case for Activity Unit Testing</h2> 55 <p>The {@link android.test.ActivityUnitTestCase} class provides support for 56 isolated testing of a single {@link android.app.Activity}. To create a unit 57 test for your {@link android.app.Activity}, your test class should extend 58 {@link android.test.ActivityUnitTestCase}.</p> 59 60 <p>The {@link android.app.Activity} in an {@link android.test.ActivityUnitTestCase} 61 is not automatically started by Android Instrumentation. To start the 62 {@link android.app.Activity} in isolation, you need to explicitly call the 63 {@link android.test.ActivityUnitTestCase#startActivity(android.content.Intent, android.os.Bundle, java.lang.Object) startActivity()} 64 method, and pass in the {@link android.content.Intent} to 65 launch your target {@link android.app.Activity}.</p> 66 67 <p>For example:</p> 68 <pre> 69 public class LaunchActivityTest 70 extends ActivityUnitTestCase<LaunchActivity> { 71 ... 72 73 @Override 74 protected void setUp() throws Exception { 75 super.setUp(); 76 mLaunchIntent = new Intent(getInstrumentation() 77 .getTargetContext(), LaunchActivity.class); 78 startActivity(mLaunchIntent, null, null); 79 final Button launchNextButton = 80 (Button) getActivity() 81 .findViewById(R.id.launch_next_activity_button); 82 } 83 } 84 </pre> 85 86 <h2 id="test_method">Validate Launch of Another Activity</h2> 87 <p id="test_goals">Your unit testing goals might include:</p> 88 <ul> 89 <li>Verifying that {@code LaunchActivity} fires an 90 {@link android.content.Intent} when a button is pushed clicked.</li> 91 <li>Verifying that the launched {@link android.content.Intent} contains the 92 correct payload data.</li> 93 </ul> 94 95 <p>To verify if an {@link android.content.Intent} was triggered 96 following the {@link android.widget.Button} click, you can use the 97 {@link android.test.ActivityUnitTestCase#getStartedActivityIntent()} method. 98 By using assertion methods, you can verify that the returned 99 {@link android.content.Intent} is not null, and that it contains the expected 100 string value to launch the next {@link android.app.Activity}. If both assertions 101 evaluate to {@code true}, you've successfully verified that the 102 {@link android.content.Intent} was correctly sent by your 103 {@link android.app.Activity}.</p> 104 105 <p>You might implement your test method like this:</p> 106 <pre> 107 @MediumTest 108 public void testNextActivityWasLaunchedWithIntent() { 109 startActivity(mLaunchIntent, null, null); 110 final Button launchNextButton = 111 (Button) getActivity() 112 .findViewById(R.id.launch_next_activity_button); 113 launchNextButton.performClick(); 114 115 final Intent launchIntent = getStartedActivityIntent(); 116 assertNotNull("Intent was null", launchIntent); 117 assertTrue(isFinishCalled()); 118 119 final String payload = 120 launchIntent.getStringExtra(NextActivity.EXTRAS_PAYLOAD_KEY); 121 assertEquals("Payload is empty", LaunchActivity.STRING_PAYLOAD, payload); 122 } 123 </pre> 124 <p>Because {@code LaunchActivity} runs in isolation, you cannot use the 125 {@link android.test.TouchUtils} library to manipulate UI controls. To directly 126 click a {@link android.widget.Button}, you can call the 127 {@link android.view.View#performClick()} method instead.</p> 128 129 130 131 132 133 134 135
