Android: Unit Test for Custom Content Provider using Roboelectric

Robolectric provides a simple approach to automate unit test case for android by using standard JUnit tests. It runs on any JVM, without needing the emulator or a device.

Advantages of Roboelectric:

No Mocking Frameworks Required

Run Tests Outside of the Emulator

Test Annotations

@RunWith

To run your test with Robolectric, you need to tell JUnit using the @RunWith annotation on your test class:

@RunWith (RobolectricTestRunner.class) // required for Robolectric!

For more details: http://pivotal.github.io/robolectric/user-guide.html
With Robolectric, we can write a small unit test for custom content provide like this.

@RunWith(RobolectricTestRunner.class)
public class BookContentProviderTest {

 private Activity activity;
 private BookProvider bookProvider;
 private ContentResolver contentResolver;

 public static final String AUTHORITY = "com.test.provider.Book";

 public static final String BOOK_TABLE_NAME = "book";

 /**
  * The columns we are interested in from the database
  */
 public static final String[] BOOK_PROJECTION = new String[] {
   BookColumns._ID, // 0
   BookColumns.BOOK_NAME, // 1
 };

 public static final Uri BOOK_URI = Uri.parse("content://" + AUTHORITY + "/"
   + BOOK_TABLE_NAME);

 private String[] bookList = new String[] { "angels and demons", "Book1",
   "Book2", "Book3" };

 @Before
 public void setUp() throws Exception {
  bookProvider = new BookProvider();
  activity = new Activity();
  contentResolver = activity.getContentResolver();

  bookProvider.onCreate();
  ShadowContentResolver.registerProvider(AUTHORITY, bookProvider);
 }

 @Test
 public void testContentProvider() {

  insertBook(new Book("53bfc0b980b0", "angels and demons"));
  insertBook(new Book("53bfc0b980b3", "Book1"));
  insertBook(new Book("53bfc0b980b1", "Book2"));
  insertBook(new Book("53bfc0b980b2", "Book3"));

  Cursor cursor = contentResolver.query(BOOK_URI, BOOK_PROJECTION, null,
    null, BookColumns.DEFAULT_SORT_ORDER);

  cursor.moveToFirst();

  Assert.assertTrue(cursor.getCount() == 4);

  if (cursor.getCount() != 0) {
   do {
    Assert.assertEquals(bookList[cursor.getPosition()],
      cursor.getString(cursor
        .getColumnIndex(BookColumns.BOOK_NAME)));
   } while (cursor.moveToNext());
  }

 }

 private void insertBook(Book book) {
  contentResolver.insert(BOOK_URI, getContentValue(book));
 }

 private ContentValues getContentValue(Book book) {
  ContentValues values;
  values = new ContentValues();
  values.put(BookColumns._ID, book.getBookId());
  values.put(BookColumns.BOOK_NAME, book.getName());
  return values;
 }
}