Junit 测试构造函数

Question

所以对于我的编程类，我们应该对继承自抽象类的一个类进行 Junit 测试。我只是对编写Junit测试感到非常困惑，因为我觉得网上没有足够的示例。我的第一个问题是，我们是否测试吸盘手和二传手？我的教授指示我们在设置测试时"选择所有"方法，但是在她要求我们阅读的网站上，他们建议不要测试getter和setter，因为JVM已经有测试器了。我的第二个也是最重要的问题是你能测试整个构造函数吗？我下面的代码基本上有一个本科生继承自抽象学生班。我假设我应该进行测试以确保本科生实际上是本科生而不是硕士生，但我不知道如何准确测试整个构造函数。任何提示将不胜感激！！

public abstract class AbstractStudent {
/**
 * First name of a student.
 */
private String myFirstName;
/**
 * Last name of a student.
 */
private String myLastName;
/**
 * Student 9-digit ID.
 */
private String myID;
/**
 * Number of credit hours completed by a student.
 */
private int myCreditHours;
/**
 * Current student GPA.
 */
private double myGPA;
/**
 * Student gender.
 */
private Gender myGender;
/** Student date of birth.
 * 
 */
private Date myBirth;
/**
 * Private constructor to prohibit default instantiation.
 */
/**
 * @param theFirstName Adds the first name into the constructor
 * @param theLastName Adds the last name into the constructor
 * @param theID Adds the ID into the constructor
 * @param theCreditHours Adds the credit hours into the constructor
 * @param theGPA Adds the GPA into the constructor
 * @param theGender Adds the gender into the constructor
 * @param theBirth Adds the birth into the constructor
 */
public AbstractStudent(final String theFirstName, final String theLastName,
                       final String theID, final int theCreditHours, final double theGPA,
                       final Gender theGender, final Date theBirth) {
    myFirstName = theFirstName;
    myLastName = theLastName;
    myID = theID;
    myCreditHours = theCreditHours;
    myGPA = theGPA;
    myGender = theGender;
    myBirth = new Date(theBirth.getTime());
}

本科生班：

public class UndergradStudent extends AbstractStudent {

/** 
 * Student status.
 */
private StudentStatus myStatus;
/**
 * Parameterized constructor - constructors a Student object.
 * @param theFirstName is a string representing the first name of a student, != null
 * @param theLastName is a string representing the last name of a student, != null
 * @param theID is a string of 9 characters representing student ID
 * @param theCreditHours is an integer number >=0 representing number of credit hours 
 *          taken by a student
 * @param theGPA is a double number representing GPA, a GPA must be >= 0 and <= 4.0
 * @param theStatus is a string representing student status, != null
 * @param theGender is a character representing student gender, != null
 * @param theBirth is a date representing student birth date; a student cannot be younger 
 *          than 10 years old 
 * @custom.post Student object constructed; if invalid parameters passed, 
 *          student is in an invalid state.
 */
public UndergradStudent(final String theFirstName, final String theLastName,
                        final String theID, final int theCreditHours, final double theGPA,
                        final StudentStatus theStatus, final Gender theGender, 
                        final Date theBirth) {
    super(theFirstName, theLastName, theID, theCreditHours, theGPA, theGender, theBirth);
    myStatus = theStatus;
}

Answer 1

我不能真正评论你教授的意图，但在编写单元测试时，你的目标是测试单个功能单元。 大多数开发人员考虑测试基本的 POJO 行为，其中 get 方法将构造函数属性作为冗余返回，但是如果您正在编写有状态的 getter/setter 方法，则值得测试。

测试UndergradStudent的整个构造函数的一种方法是将实例构造为私有最终变量或使用 JUnit 的@BeforeClass注释并为每个属性 getter 编写单独的@Test。