Testing Room Migrations

DatabaseInstrumentedTest.java

@RunWith(AndroidJUnit4.class)
public class DatabaseInstrumentedTest {

    private static final String TEST_DB_NAME = "test_database";

    @Rule
    public MigrationTestHelper testHelper =
            new MigrationTestHelper(
                    InstrumentationRegistry.getInstrumentation(),
                    TestDatabase.class.getCanonicalName(),
                new FrameworkSQLiteOpenHelperFactory()
            );

    @Test
    public void testAllMigrations() throws IOException {
        testHelper.createDatabase(TEST_DB_NAME, 1);
        testHelper.runMigrationsAndValidate(TEST_DB_NAME, Constants.DB_VERSION, true, migrations);
    }
}

DatabaseModule.java

public class DatabaseModule {

    private static final Migration MIGRATION_1_2 = new Migration(1, 2) {
        @Override
        public void migrate(SupportSQLiteDatabase database) {
            database.execSQL("DROP TABLE IF EXISTS dummy_table");
        }
    };
    
    @NonNull
    public static Migration[] migrations = {
            MIGRATION_1_2
    };
}