Accessing resources in an android test project

Question

I have setup an android test project that runs junit tests. It\'s using two eclipse projects \"Application\" and \"ApplicationTest\" where my tests are in the \"ApplicationT

Answer 1

With build tools 3.0.0 you can use ActivityTestRule

@RunWith(AndroidJUnit4::class)
@SmallTest
class MainActivityTest {
    @Rule
    @JvmField
    var mainActivityRule = ActivityTestRule(MainActivity::class.java)

    private val baseUrl: String
        get() {
            return mainActivityRule.activity.getString(R.string.base_url)
        }

    @Test
    fun launchingWithMovieIntent() {
            assert.that(baseUrl, equalTo("someValue")
        }
    }
}

Answer 2

I would suggest extending ActivityTestCase instead of AndroidTestCase. You can than access test project resources via

getInstrumentation().getContext().getResources().openRawResource(R.raw.your_res).

Dummy test case example:

public class Test extends ActivityTestCase {

   public void testFoo() {  

      // .. test project environment
      Context testContext = getInstrumentation().getContext();
      Resources testRes = testContext.getResources();
      InputStream ts = testRes.openRawResource(R.raw.your_res);

      assertNotNull(testRes);
   }    
}

And then in test methods use getInstrumentation().getTargetContext() wherever you used getContext() in your AndroidTestCase extension.

Answer 3

Since Android Gradle Plugin version 1.1 you haven't to use Instrumentation to load file resource.

I wrote here how to do it with POJO unit test case.

Answer 4

I derived the test case as follows:

class MyTest extends InstrumentationTestCase {
    void setUp() {
        InputStream is = getInstrumentation().getContext().getAssets()
            .open("test_image.bmp");
        ...
   }
}

And the file test_image.bmp is saved in assets directory, which is reasonable if you intend to use the asset for some testing related work - and its not part of ui resources. The technique is used in another context here: https://stackoverflow.com/a/4570206/1577626