A pair of hamcrest matchers to check for activity results / intent data.

ActivityResultMatchers.java

/**
 * A pair of hamcrest matchers that expose the result code and intent data of activities.
 * 
 * Usage:
 * 
 * @RunWith(AndroidJUnit4.class)
 * public class YourActivityTest extends ActivityTestBase {
 *    @Rule
 *    public final ActivityTestRule<YourActivity> mActivityTestRule = new ActivityTestRule<>(YourActivity.class);
 * 
 *    @Test
 *    public void testFinishing() {
 *		    // do something that triggers your activity to finish with a result code
 *        assertThat(mActivityTestRule.getActivity().isFinishing(), is(true));
 *        assertThat(mActivityTestRule.getActivity(), hasActivityResultCode(Activity.RESULT_OK));
 *    }
 * }
 * 
 * License: Apache Software License, v2
 * Author: Thomas Keller <me@thomaskeller.biz>
 */
public class ActivityResultMatchers {
    private ActivityResultMatchers() {
    }

    /**
     * Checks whether an activity has a specific result code set
     *
     * @param resultCode
     * @return
     */
    public static TypeSafeMatcher<Activity> hasActivityResultCode(final int resultCode) {
        return new TypeSafeMatcher<Activity>(Activity.class) {
            private static final String FIELD_NAME = "mResultCode";

            @Override
            public void describeTo(Description description) {
                description.appendText("matches activity with result code ");
                description.appendValue(resultCode);
            }

            @Override
            protected boolean matchesSafely(Activity item) {
                try {
                    Field field = Activity.class.getDeclaredField(FIELD_NAME);
                    field.setAccessible(true);
                    return field.getInt(item) == resultCode;
                } catch (Exception e) {
                    throw new IllegalStateException("cannot find or access " + FIELD_NAME + " on Activity", e);
                }
            }
        };
    }

    /**
     * Checks whether an activity has a specific result intent set
     *
     * @param intentMatcher
     * @return
     */
    public static TypeSafeMatcher<Activity> hasActivityResultIntent(final Matcher<Intent> intentMatcher) {
        return new TypeSafeMatcher<Activity>(Activity.class) {
            private static final String FIELD_NAME = "mResultData";

            @Override
            public void describeTo(Description description) {
                description.appendText("matches activity with intent: ");
                intentMatcher.describeTo(description);
            }

            @Override
            protected boolean matchesSafely(Activity item) {
                try {
                    Field field = Activity.class.getDeclaredField(FIELD_NAME);
                    field.setAccessible(true);
                    return intentMatcher.matches(field.get(item));
                } catch (Exception e) {
                    throw new IllegalStateException("cannot find or access " + FIELD_NAME + " on Activity", e);
                }
            }
        };
    }
}