@RunWith(Suite.class)
@ContextConfiguration(classes = MainApp.class)
@SpringBootTest
@WebAppConfiguration
@Suite.SuiteClasses({ BackendTests.class, Frontend.class })
public class JunitTestSuite {

    @Autowired
    DataSource dataSource;

    @ClassRule
    public static JunitTestWatcher extentWatcher = new JunitTestWatcher() {

        @Override
        protected void finished(Description description) {
            System.out.println(dataSource);      //dataSource is null
            jdbcTemplate = new JdbcTemplate(dataSource);
        }
    };
}

spring.datasource.url = jdbc:mysql://localhost/junit
spring.datasource.username = cm189
spring.datasource.password = 23dy-.390saef
spring.datasource.driver-class = com.mysql.jdbc.Driver

@Autowired
 DataSource dataSource;