使用 JUnit 和 Mockito 对 DAO 类进行单元测试

Question

I have DaoImpl class:

public class MessageTypeDaoImpl implements MessageTypeDao{

    public int[] createMessageTypes(final List<MessageType> messageTypes){
        String sql = "INSERT INTO MSG_TYPE VALUES(?, ?)";
        return jdbcTemplate.batchUpdate(sql, new BatchPreparedStatementSetter() {
            public void setValues(PreparedStatement ps, int i) throws SQLException {
                MessageType messageType = messageTypes.get(i);
                ps.setString(1, messageType.getMessageId());
                ps.setString(2, messageType.getMessageName());
            }

            public int getBatchSize(){
                return messageTypes.size();
            }
    });
}

And my test:

@RunWith(MockitoJUnitRunner.class)
public class MessageTypeDaoImplTest {

@Mock
private JdbcTemplate jdbcTemplate;

@Spy
@InjectMocks
MessageTypeDaoImpl messageTypeDaoImpl;
@Before
public void setUp(){
    MockitoAnnotations.initMocks(this);
}
@Test
public void createMessageTypes() {
    int[] returnCount = new int[1];
    List<MessageType> messageTypeList = new ArrayList<MessageType>();
    messageTypeList.add(getSampleMessageType());
    messageTypeDaoImpl.createMessageTypes(messageTypeList);
    doReturn(returnCount).when(messageTypeDaoImpl).createMessageTypes(messageTypeList);
    assertEquals(returnCount, messageTypeDaoImpl.createMessageTypes(messageTypeList));
}
}

public MessageType getSampleMessageType(){
    return new MessageType("messageTypeId", "messageTypeName");
}

Test is successful but when I run junit test with coverage it shows public void setValues() method is not being covered, hence my overall unit test line coverage is below the requirements. Can we cover that part? And if yes then how we do it? Thanks.

Answer 1

Try this below code spinet. I will cover the code as well. I check it from my end, and it worked.

int[] batchInsert=new int[] {1,2};
        try {

            Mockito.doAnswer(invocationOnMock -> {

                PreparedStatement ps = Mockito.mock(PreparedStatement.class);
                BatchPreparedStatementSetter psr = invocationOnMock.getArgument(1);
                psr.setValues(ps, 1);
                return batchInsert;

            }).when(jdbcTemplate).batchUpdate(anyString(),  Mockito.any(BatchPreparedStatementSetter.class));