Junit 测试失败，但我的方法在 Java 作业中似乎很好

Question

我正在做一项下周到期的作业 所以基本上我有一个具有以下属性的 User 类

private String userName, password;
private final Instant registrationDate;
private HashSet<User> setSubs;
private ArrayList<Post> listPosts;
private int Index;

我尝试测试的方法是

    public Post addPost(String msg) {
        listPosts.add(new Post(msg));
        Index++;
        return new Post(msg);
    }

和

    public Post getPost(int i) {
        return listPosts.get(i);
    }

这是类 Post 属性

    private final String textPost; 
    private final Instant dateCreation; //this.dateCreation = Instant.now();
    private HashSet<User> likedUsers;

这是我面临的问题，在测试方法 addPost 时，它给出错误 org.opentest4j.AssertionFailedError: Expected: but was: ，当查看测试的类时，我注意到它在这一点上失败了

for (int i = 0; i < (self.getPostNb() - 1); i++) { //getPostNb() = listPost.size()
        assertTrue(self.getPost(i).isAfter(self.getPost(i + 1)));
    }

对于 getPost 方法，它会给出错误 java.lang.IllegalArgumentException：即使运行测试，绑定也必须为正

请问有什么建议可以修复它们吗？ 谢谢

我需要 Junit 测试全部返回成功，但只有 addPost 和 getPost 失败，这使得使用它们的其他两个方法也被中止

编辑： 断言不变方法

 public void assertInvariant(User self) {
    // Put here the code to check the invariant:
    // @invariant getName() != null && !getName().isBlank();
    assertNotNull(self.getName());
    assertFalse(self.getName().isBlank());
    // @invariant getPassword() != null && !getPassword().isBlank();
    assertNotNull(self.getPassword());
    assertFalse(self.getPassword().isBlank());
    // @invariant getRegistrationDate() != null;
    assertNotNull(self.getRegistrationDate());
    // @invariant getSubscriptions() != null && !getSubscriptions().contains(null);
    assertNotNull(self.getSubscriptions());
    assertFalse(self.getSubscriptions().contains(null));
    // @invariant getSubscriptionNb() == getSubscriptions().size();
    assertEquals(self.getSubscriptionNb(), self.getSubscriptions().size());
    // @invariant getPosts() != null && !getPosts().contains(null);
    assertNotNull(self.getPosts());
    assertFalse(self.getPosts().contains(null));
    // @invariant (\forall int i, j; i >= 0 && i < j && j < getPostNb(); getPost(i).isAfter(getPost(j)));
    for (int i = 0; i < (self.getPostNb() - 1); i++) {
        assertTrue(self.getPost(i).isAfter(self.getPost(i + 1)));
    }
    // @invariant getPostNb() == getPosts().size();
    assertTrue(self.getPostNb() == self.getPosts().size());
    // @invariant previousIndex() >= -1 && previousIndex() < getPosts().size();
    assertTrue(self.previousIndex() >= -1);
    assertTrue(self.previousIndex() < self.getPosts().size());
    // @invariant nextIndex() >= 0 && nextIndex() <= getPosts().size();
    assertTrue(self.nextIndex() >= 0);
    assertTrue(self.nextIndex() <= self.getPosts().size());
    // @invariant nextIndex() == previousIndex() + 1;
    assertTrue(self.nextIndex() == self.previousIndex() + 1);
    // @invariant lastIndex() >= -1 && lastIndex() < getPosts().size();
    assertTrue(self.lastIndex() >= -1);
    assertTrue(self.lastIndex() < self.getPosts().size());
    // @invariant lastIndex() == previousIndex() || lastIndex() == nextIndex();
    assertTrue(self.lastIndex() == self.previousIndex() || self.lastIndex() == self.nextIndex());
}

addPost的测试方法

    @ParameterizedTest
    @MethodSource("userAndStringProvider")
    public void testaddPost(User self, String msg) {
    assumeTrue(self != null);

    // Invariant:
    assertInvariant(self);

    // Pré-conditions:
    // @requires msg != null;
    assumeTrue(msg != null);

    // Oldies:
    Instant oldDate = Instant.now();
    // Wait until oldDate is really old:
    ArrayList<User> list = new ArrayList<User>(1);
    while (!oldDate.isBefore(Instant.now())) {
        list.add(self);
    }
    // old in:@ensures getPostNb() == \old(getPostNb()) + 1;
    int oldPostNb = self.getPostNb();
    // @ensures \old(lastIndex() >= 0) ==> nextIndex() == \old(nextIndex() + 1);
    int oldNextIndex = self.nextIndex();
    // @ensures \old(lastIndex() >= 0) ==> previousIndex() == \old(previousIndex() + 1);
    int oldPrevIndex = self.previousIndex();
    // @ensures \old(lastIndex() >= 0) ==> lastIndex() == \old(lastIndex() + 1);
    int oldLastIndex = self.lastIndex();

    // Exécution:
    Post result = self.addPost(msg);

    // Wait until exec date is really old:
    Instant execDate = Instant.now();
    while (!execDate.isBefore(Instant.now())) {
        list.add(null);
    }
    list = null;
    // Post-conditions:
    // @ensures getPost(0).equals(\result);
    assertEquals(self.getPost(0), result);
    // @ensures \result.getText().equals(msg);
    assertEquals(msg, result.getText());
    // @ensures getPostNb() == \old(getPostNb()) + 1;
    assertEquals(oldPostNb + 1, self.getPostNb());
    // @ensures oldDate.isBefore(\result.getDate());
    assertTrue(oldDate.isBefore(result.getDate()));
    // @ensures \result.getDate().isBefore(Instant.now());
    assertTrue(result.getDate().isBefore(Instant.now()));
    if (oldLastIndex >= 0) {
        // @ensures \old(lastIndex() >= 0) ==> nextIndex() == \old(nextIndex() + 1);
        assertEquals(oldNextIndex + 1, self.nextIndex());
        // @ensures \old(lastIndex() >= 0) ==> previousIndex() == \old(previousIndex() + 1);
        assertEquals(oldPrevIndex + 1, self.previousIndex());
        // @ensures \old(lastIndex() >= 0) ==> lastIndex() == \old(lastIndex() + 1);
        assertEquals(oldLastIndex + 1, self.lastIndex());
    } else {
        // @ensures \old(lastIndex() == -1) ==> nextIndex() == \old(nextIndex());
        assertEquals(oldNextIndex, self.nextIndex());
        // @ensures \old(lastIndex() == -1) ==> previousIndex() == \old(previousIndex());
        assertEquals(oldPrevIndex, self.previousIndex());
        // @ensures \old(lastIndex() == -1) ==> lastIndex() == \old(lastIndex());
        assertEquals(oldLastIndex, self.lastIndex());
    }

    // Invariant:
    assertInvariant(self);
}

getPost的测试方法

    public void testgetPost(User self, int i) {
    assumeTrue(self != null);

    // Invariant:
    assertInvariant(self);

    // Pré-conditions:
    // @requires i >= 0 && i < getPostNb();
    assumeTrue(i >= 0 && i < self.getPostNb());

    // Save state for purity check:
    saveState(self);

    // Oldies:

    // Exécution:
    Post result = self.getPost(i);

    // Post-conditions:
    // @ensures \result.equals(getPosts().get(i));
    assertEquals(self.getPosts().get(i), result);

    // Assert purity:
    assertPurity(self);

    // Invariant:
    assertInvariant(self);
}

isAfter/isBefore 方法

public boolean isAfter(Post p) {
return getDate().isAfter(p.getDate()); //getDate().isBefore(p.getDate())
}

PS。我不应该改变测试方法

Answer 1

您将新帖子添加到

listPosts

的末尾：

    public Post addPost(String msg) {
        listPosts.add(new Post(msg));
        Index++;
        return new Post(msg);
    }

这意味着帖子按

dateCreation

升序排列（即先创建

listPosts.get(0)

，然后是

listPosts.get(1)

，然后是后面的帖子），这也意味着

    self.getPost(i).isAfter(self.getPost(i + 1))

永远不可能是真的。您要么必须将该条件更改为

    self.getPost(i).isBefore(self.getPost(i + 1))

或将新帖子添加到列表前面：

    public Post addPost(String msg) {
        listPosts.add(0, new Post(msg));
        Index++;
        return new Post(msg);
    }

---

另请注意，

addPost()

创建了两个不同的

Post

对象，这可能不是您想要的。你可能想要

    public Post addPost(String msg) {
        Post post = new Post(msg);
        listPosts.add(0, post);
        Index++;
        return post;
    }

---

对于带有消息“绑定必须为正”的

IllegalArgumentException

：

对 JDK17 源代码的搜索导致该消息有一个可能的原因：调用上限小于零的随机生成器。

由于您的代码不包含随机生成器的任何用法，因此不可能说出问题是什么。

也许当您包含该异常的堆栈跟踪时，可以帮助确定问题。