如何增加与数据库交互的 Class 的测试覆盖率？

Question

我有一个名为 PatientRepositoryImpl 的 Java class，它包含一些方法，可以在 MySql 数据库中插入、删除或更新数据。我还为此 class 编写了一些单元测试。当我检查我的测试的覆盖率时，我只得到 59%，尽管几乎每一行代码都被覆盖率工具标记为绿色，除了 SQL 异常。我是新来的，希望我做的一切正确，如果有人能帮助我，我将不胜感激。

这是我的存储库和测试的代码。

public class PatientRepositoryMySqlImpl implements PatientRepository {


private DatabaseConnection connection;
private PatientGenerator patientGenerator;


public PatientRepositoryMySqlImpl(DatabaseConnection connection, PatientGenerator patientGenerator) {
    this.connection = connection;
    this.patientGenerator = patientGenerator;
}

/* (non-Javadoc)
 * @see com.id.hl7sim.PatientRepository#insertPatient()
 */
@Override
public void insertPatient(Patient patient) {
    if (!patient.isValid()) { 
        throw new IllegalArgumentException("Incomplete Patient");
    } else {
        String insert = "INSERT INTO tbl_patient(lastname, firstname, gender, birthday) VALUES('"
        + patient.getLastname() + "', '" + patient.getFirstname() + "', '" + patient.getGender() + "', '"
        + patient.getBirthday().toString() + "');";
        try (Connection dbConnection = connection.getDBConnection();
             Statement statement = dbConnection.prepareStatement(insert)) {
            statement.executeUpdate(insert);
        } catch (SQLException e) {
            System.out.println(e.getMessage());
        }
    }
}

/* (non-Javadoc)
 * @see com.id.hl7sim.PatientRepository#insertListOfPatients()
 */
@Override
public void insertListOfPatients(List<Patient> allPatients) {
    for (Patient patient : allPatients) {
        insertPatient(patient);
    }
}

/* (non-Javadoc)
 * @see com.id.hl7sim.PatientRepository#getRandomPatient()
 */
@Override
public Patient getRandomPatient() {
    Patient patient = new Patient.Builder().build();
    String query = "SELECT * FROM tbl_patient ORDER BY RAND() LIMIT 1";
    try (Connection dbConnection = connection.getDBConnection();
         Statement statement = dbConnection.createStatement();) {
        ResultSet rs = statement.executeQuery(query);
        rs.next();
        setPatientBasicData(patient, rs);
    } catch (SQLException e) {
        System.out.println(e.getMessage());
    }
    return patient;
}

private void setPatientBasicData(Patient patient, ResultSet rs) {
    try {
        patient.setId(rs.getInt("id"));
        patient.setLastname(rs.getString("lastname"));
        patient.setFirstname(rs.getString("firstname"));
        patient.setGender(rs.getString("gender"));
        patient.setBirthday(parseBirthday(rs.getString("birthday")));
    } catch (SQLException e) {
        System.out.println(e.getMessage());
    }
}

public LocalDate parseBirthday(String birthday) {
    LocalDate localDate = LocalDate.parse(birthday);
    return localDate;
}

/* (non-Javadoc)
 * @see com.id.hl7sim.PatientRepository#admitRandomPatient()
 */
@Override
public Patient admitRandomPatient() {
    Patient patient = getRandomPatient();
    patient.setDepartment(patientGenerator.getRandomDepartment());
    patient.setWard(patientGenerator.getRandomWard());
    patient.setAdmissionDateTime(LocalDateTime.now());
    patient.setStatus("I");
    String insert = "INSERT INTO tbl_inpatients(id, ward, department, admissionDate, patientStatus) VALUES('"
                    + patient.getId() + "', '" + patient.getWard() + "', '" + patient.getDepartment() + "', '"
                    + patient.getAdmissionDateTime().toString() + "', '" + patient.getStatus() + "')";
    try (Connection dbConnection = connection.getDBConnection();
         PreparedStatement statement = dbConnection.prepareStatement(insert)) {
        statement.executeUpdate(insert, Statement.RETURN_GENERATED_KEYS);
        ResultSet keys = statement.getGeneratedKeys();
        keys.next();
        patient.setCaseId(keys.getInt(1));
    } catch (SQLException e) {
        System.out.println(e.getMessage());
    }
    return patient;
}

public Patient getRandomInpatient() {
    Patient patient = new Patient.Builder().build();
    String query = "SELECT * FROM tbl_inpatients ip, tbl_patient p WHERE p.id = ip.id  ORDER BY RAND() LIMIT 1";
    try (Connection dbConnection = connection.getDBConnection();
         Statement statement = dbConnection.createStatement();) {
        ResultSet rs = statement.executeQuery(query);
        rs.next();
        setPatientBasicData(patient, rs);
        setPatientCaseData(patient, rs);
    } catch (SQLException e) {
        System.out.println(e.getMessage());
    }
    return patient;
}

public void setPatientCaseData(Patient patient, ResultSet rs) {
    try {
        patient.setWard(rs.getString("ward"));
        patient.setDepartment(rs.getString("department"));
        patient.setAdmissionDateTime(parseLocalDateTime(rs.getString("admissionDate")));
        patient.setStatus(rs.getString("patientStatus"));
        patient.setCaseId(rs.getInt("case"));
    } catch (SQLException e) {
        System.out.println(e.getMessage());
    }
}

public LocalDateTime parseLocalDateTime(String localdatetime) {
    localdatetime = localdatetime.replace("T", "");
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-ddHH:mm:ss.SSS");
    LocalDateTime formattedLocalDateTime = LocalDateTime.parse(localdatetime, formatter);
    return formattedLocalDateTime;
}

/* (non-Javadoc)
 * @see com.id.hl7sim.PatientRepository#transferRandomPatient()
 */
@Override
public Patient transferRandomPatient() {
    Patient patient = getRandomInpatient();
    patient.setPriorWard(patient.getWard());
    patient.setPriorDepartment(patient.getPriorDepartment());
    patient.setDepartment(patientGenerator.getRandomDepartment());
    patient.setWard(patientGenerator.getRandomWard());
    String update = "UPDATE tbl_inpatients SET ward='" + patient.getWard() + "', department='"
            + patient.getDepartment() + "' WHERE id='" + patient.getId() + "'";
    try (Connection dbConnection = connection.getDBConnection();
         Statement statement = dbConnection.prepareStatement(update)) {
        statement.executeUpdate(update);
    } catch (SQLException e) {
        System.out.println(e.getMessage());
    }
    return patient;
}

/* (non-Javadoc)
 * @see com.id.hl7sim.PatientRepository#dischargeRandomPatient()
 */
@Override
public Patient dischargeRandomPatient() {
    Patient patient = getRandomInpatient();
    patient.setDischargeDateTime(LocalDateTime.now());
    insertFormerPatient(patient);
    String delete = "DELETE FROM tbl_inpatients WHERE `case`=" + patient.getCaseId();
    try (Connection dbConnection = connection.getDBConnection();
         Statement statement = dbConnection.prepareStatement(delete)) {
        statement.executeUpdate(delete);
    } catch (SQLException e) {
        System.out.println(e.getMessage());
    }
    return patient;
}

public void insertFormerPatient(Patient patient) {
    String insert = "INSERT INTO tbl_formerpatients(`case`, `id`, ward, department, admissionDate, dischargeDate) VALUES('"
            + patient.getCaseId() + "', '" + patient.getId() + "', '" + patient.getWard() + "', '"
            + patient.getDepartment() + "', '" + patient.getAdmissionDateTime().toString() + "', '"
            + patient.getDischargeDateTime().toString() + "')";
    try (Connection dbConnection = connection.getDBConnection();
         Statement statement = dbConnection.prepareStatement(insert)) {
        statement.executeUpdate(insert);
    } catch (SQLException e) {
        System.out.println(e.getMessage());
    }
}

public int countInpatients() {
    int numberOfPatients = 0;
    String query = "SELECT COUNT(id) AS numberOfPatients FROM tbl_inpatients";
    try (Connection dbConnection = connection.getDBConnection();
            Statement statement = dbConnection.createStatement();) {
        ResultSet rs = statement.executeQuery(query);
        while (rs.next()) {
            numberOfPatients = rs.getInt(1);
        }
    } catch (SQLException e) {
        System.out.println(e.getMessage());
    }
    return numberOfPatients;
}

public int countPatients() {
    int numberOfPatients = 0;
    String query = "SELECT COUNT(id) AS numberOfPatients FROM tbl_patient";
    try (Connection dbConnection = connection.getDBConnection();
            Statement statement = dbConnection.createStatement();) {
        ResultSet rs = statement.executeQuery(query);
        while (rs.next()) {
            numberOfPatients = rs.getInt(1);
        }
    } catch (SQLException e) {
        System.out.println(e.getMessage());
    }
    return numberOfPatients;
}

测试

public class PatientRepositoryMySqlImplTest {

PatientRepository testPatientRepository;

Patient testPatient;

Patient testPatientTwo;

List<Patient> testBothPatients;

DatabaseConnection testConnection;

PatientGenerator testPatientGenerator;

Firstnames testFirstnames;

Lastnames testLastnames;

Departments testDepartments;

Wards testWards;

@Before
public void setUp() throws Exception {

    testDepartments = JAXB.unmarshal(ClassLoader.getSystemResource("departments.xml"), Departments.class);
    testWards = JAXB.unmarshal(ClassLoader.getSystemResource("wards.xml"), Wards.class);
    testLastnames = JAXB.unmarshal(ClassLoader.getSystemResource("lastnames.xml"), Lastnames.class);
    testFirstnames = JAXB.unmarshal(ClassLoader.getSystemResource("firstnames.xml"), Firstnames.class);

    testPatientGenerator = new PatientGeneratorImpl(testFirstnames, testLastnames, testDepartments, testWards);

    testPatient = testPatientGenerator.randomizeNewPatient();

    testPatientTwo = testPatientGenerator.randomizeNewPatient();

    testBothPatients = new ArrayList<Patient>();

    testConnection = new MySqlConnection();

    testPatientRepository = new PatientRepositoryMySqlImpl(testConnection, testPatientGenerator);

    testPatientRepository.admitRandomPatient();

}

@Test
public void testAdmitRandomPatient() {

    testPatient = testPatientRepository.admitRandomPatient();

    assertTrue(testPatient.isValid());
}

@Test
public void testGetRandomInpatient() {

    testPatient = testPatientRepository.getRandomInpatient();

    assertTrue(testPatient.isValid());
}

@Test
public void testDischargeRandomPatientValid() {

    testPatient = testPatientRepository.dischargeRandomPatient();

    assertTrue(testPatient.isValid());
    assertTrue(testPatient.getCaseId() != 0);
}

@Test
public void testDischargeRandomPatientDatabase() {

    int beforeDischarge = testPatientRepository.countInpatients();
    testPatient = testPatientRepository.dischargeRandomPatient();
    int afterDischarge = testPatientRepository.countInpatients();

    assertTrue(afterDischarge == beforeDischarge - 1);

}

@Test(expected = IllegalArgumentException.class)
public void testInsertPatientWitIncompletePatient() {

    testPatient.setFirstname("");

    testPatientRepository.insertPatient(testPatient);
}

@Test
public void testTransferRandomPatient() {

    testPatient = testPatientRepository.transferRandomPatient();

    assertTrue(testPatient.getDepartment() != testPatient.getPriorDepartment());
}

@Test
public void testInsertPatient() {

    int numberOfPatients = testPatientRepository.countInpatients();

    testPatientRepository.insertPatient(testPatient);

    assertTrue(testPatientRepository.countInpatients() >= numberOfPatients);
}

@Test
public void testInsertListOfPatients() {

    testBothPatients.add(testPatient);
    testBothPatients.add(testPatientTwo);

    int countInpatientsBeforeInsertion = testPatientRepository.countPatients();

    testPatientRepository.insertListOfPatients(testBothPatients);

    int countInpatientsAfterInsertion = testPatientRepository.countPatients();
    assertTrue(countInpatientsAfterInsertion > countInpatientsBeforeInsertion);

}

编辑：

@Test
public void mockThrowsException() {

    PatientRepository testPatientRepository = mock(PatientRepositoryMySqlImpl.class);

    when(testPatientRepository.getRandomPatient()).thenThrow(SQLException.class);

    testPatientRepository.admitRandomPatient();

}

Answer 1

虽然我完全同意，为了增加覆盖率，您绝对应该 "simulate" 出现问题并抛出 SQLException 的情况，但让我介绍另一种方法，它也可以回答问题，但希望能给你另一个视角。

JDBC 非常麻烦，而且会抛出 SQL 异常的测试可能不是最适合编写的测试。另外，我看到你并没有真正处理异常，只是将它们记录在控制台中。

所以也许你应该考虑不直接使用 JDBC，而是使用一些库来解决 JDBC 使用的麻烦，而不是试图为此而苦苦挣扎。例如这样一个库，看看 Spring JDBC Template，我知道这是一个很老的东西，但是嘿，直接使用 JDBC 也可能不是最现代的方法，所以我正在尝试进行更少的更改但仍然获得价值。此外，有人可能会说它古老而不花哨，我会说，这是一个久经沙场的图书馆，即使没有 Spring 本身也可以。

现在，由于它包装了 JDBC 异常处理等，关键是您根本不必涵盖这些情况。所以你的覆盖率自然会增加。

当然存在其他低级别和不那么低级别的替代方案（例如 JDBI, or JOOQ 等），但这是一个不同的故事，所有这些都会在某种意义上增加覆盖率你问过的问题。

如何增加与数据库交互的 Class 的测试覆盖率？

How to increase Testcoverage for Class that interacts with a Database?

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test-coverage