Android JUnit tests can't call any android api?

Question

From Android\'s Testing Fundamentals, \"You can use plain JUnit to test a class that doesn\'t call the Android API, or Android\'s JUnit extensions to test Android components

Answer 1

I was running into a similar problem with a SpannableStringBuilder. My problem was solved by moving my test to the androidTest directory. (Thanks to this answer for the suggestion.)

Here is the test in the new location:

/**
 * Instrumentation test, which will execute on an Android device.
 *
 * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
 */
@RunWith(AndroidJUnit4.class)
public class ExampleInstrumentedTest {

    @Test
    public void myStringTest() throws Exception {
        CharSequence unicode = "";
        MyClass myClass = new MyClass(unicode); 
        CharSequence result = myClass.getUnicodeText(); // uses SpannableStringBuilder internally
        CharSequence expected = unicode;
        assertEquals(expected, result);
    }
}

Note

You can also try mocking the Android classes, but this was a lot easier for a Testing beginner like me. The disadvantage, I suppose, is that the instrumentation tests run slower than Unit tests.