实现我自己的堆栈时测试用例不起作用

Question

所以我们的作业是在我们的 won 上实现一个堆栈，然后为它编写测试用例。 这是堆栈：

    import java.util.Vector;

class Stack<T> extends Vector<T> {
    private Vector<T> stack;

    Stack() {
        stack = new Vector<T>();
    }

    // returns false or true, given the stack is empty or not.
    public boolean isEmpty() {
        return stack.size() == 0;
    }

    //returns the top element of the stack without removing it.
    public T peek() {
        return stack.get(stack.size()-1);
    }

    //puts a new element to the top of the stack
    public void push(T element) {
        stack.add(element);
    }

    //returns and removes the top element of the stack
    public T pop() {
        return stack.get(stack.size()-1);
    }
}

这是我目前的测试课。

import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.*;

class StackTest {

    @Test
    void isEmpty() {
        stack s = new stack<Integer>;
        assertEquals(true, s.isEmpty());
    }

    @Test
    void peek() {
        Stack t = new Stack(1);
    }

    @Test
    void push() {
    }

    @Test
    void pop() {
    }

}

我真的很难弄清楚前两种测试方法有什么问题。其他人有想法吗？

Answer 1

这是错误的：

//returns and removes the top element of the stack
public T pop() {
    return stack.get(stack.size()-1);
}

你不删除元素，用remove代替get

其他错误：

void isEmpty() {
    //Typo errors here, s is uppercase and missing parenthesis
    stack s = new stack<Integer>;
    assertEquals(true, s.isEmpty());
}

@Test
void peek() {
    //What does Stack(1) mean? There is no such constructor in class
    Stack t = new Stack(1);
}

还有：

//If you already extend Vector you don't need a Vector field for the data
class Stack<T> extends Vector<T> {
    private Vector<T> stack;