Android - AssertionFailedError on startActivity method in ActivityUnitTestCase test class

Question

I am trying to test an activity in a module. I am just trying to start this activity in the test method, but I always have a AssertionFailedError. I searched the web for this issue but could not find any solution. Any help is appreciated.

This is my test class:

public class ContactActivityTest extends ActivityUnitTestCase<ContactActivity> {

    public ContactActivityTest() {
        super(ContactActivity.class);
    }


    @Override
    public void setUp() throws Exception {
        super.setUp();
    }


    public void testWebViewHasNotSetBuiltInZoomControls() throws Exception {
        Intent intent = new Intent(getInstrumentation().getTargetContext(),
                ContactActivity.class);
        startActivity(intent, null, null);
    }


    @Override
    public void tearDown() throws Exception {
        super.tearDown();
    }
}

And this is the error:

junit.framework.AssertionFailedError
at android.test.ActivityUnitTestCase.startActivity(ActivityUnitTestCase.java:147)
at com.modilisim.android.contact.ContactActivityTest.testWebViewHasNotSetBuiltInZoomControls(ContactActivityTest.java:29)
at android.test.InstrumentationTestCase.runMethod(InstrumentationTestCase.java:214)
at android.test.InstrumentationTestCase.runTest(InstrumentationTestCase.java:199)
at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:191)
at android.test.AndroidTestRunner.runTest(AndroidTestRunner.java:176)
at android.test.InstrumentationTestRunner.onStart(InstrumentationTestRunner.java:555)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1763)

Regards.

Answer 1

ActivityUnitTestCase's startActivity() method needs to be called on the main thread only.

This can be done in the following ways:

1. Use the @UiThreadTest annotation before your test method:

   @UiThreadTest
   public void testWebViewHasNotSetBuiltInZoomControls() throws Exception {
       Intent intent = new Intent(getInstrumentation().getTargetContext(),
               ContactActivity.class);
       startActivity(intent, null, null);
   }
   

2. Use the runOnMainSync method of the Instrumentation class:

   public void testWebViewHasNotSetBuiltInZoomControls() throws Exception {
       final Intent intent = new Intent(getInstrumentation().getTargetContext(),
               ContactActivity.class);
   
       getInstrumentation().runOnMainSync(new Runnable() {
           @Override
           public void run() {
               startActivity(intent, null, null);
              }
           });
    }
   

Why am I right?