尝试编写单元测试无法解决？

Question

为addInventory() 编写单元测试。使用参数sweaterShipment 调用redSweater.addInventory()。如果后续数量不正确，则打印显示的错误。给定初始数量为 10 且 sweaterShipment 为 50 的失败单元测试的样本输出：

开始测试。单元测试失败：addInventory() 测试完成。注意： UNIT TEST FAILED 前面有 3 个空格。

  // ===== Code from file InventoryTag.java =====
  public class InventoryTag {
    private int quantityRemaining;

    public InventoryTag() {
      quantityRemaining = 0;
    }

    public int getQuantityRemaining() {
       return quantityRemaining;
    }

    public void addInventory(int numItems) {
      if (numItems > 10) {
         quantityRemaining = quantityRemaining + numItems;
      }
    }
  }// ===== end =====



   // ===== Code from file CallInventoryTag.java =====
    public class CallInventoryTag {
       public static void main (String [] args) {
           InventoryTag redSweater = new InventoryTag();
           int sweaterShipment;
           int sweaterInventoryBefore;

           sweaterInventoryBefore = redSweater.getQuantityRemaining();
           sweaterShipment = 25;

           System.out.println("Beginning tests.");

           // FIXME add unit test for addInventory
           System.out.println("Tests complete.");
       }

     }// ===== end =====

Answer 1

这是班级正在寻找的解决方案（我花了一段时间才弄清楚他们想要的特定解决方案）：

// ===== Code from file InventoryTag.java =====
public class InventoryTag {
   private int quantityRemaining;

   public InventoryTag() {
      quantityRemaining = 0;
   }

   public int getQuantityRemaining() {
      return quantityRemaining;
   }

   public void addInventory(int numItems) {
      if (numItems > 10) {
         quantityRemaining = quantityRemaining + numItems;
      }
   }
}
// ===== end =====

// ===== Code from file CallInventoryTag.java =====
public class CallInventoryTag {
   public static void main (String [] args) {
      InventoryTag redSweater = new InventoryTag();
      int sweaterShipment;
      int sweaterInventoryBefore;

      sweaterInventoryBefore = redSweater.getQuantityRemaining();
      sweaterShipment = 25;

      System.out.println("Beginning tests.");

      // FIXME add unit test for addInventory
      /* Your solution starts here  */    
       redSweater.addInventory(sweaterShipment);

      if (sweaterInventoryBefore + sweaterShipment != redSweater.getQuantityRemaining()) {
         System.out.println("   UNIT TEST FAILED: addInventory()");
      }

      /* End of your solution*/    

      System.out.println("Tests complete.");
   }
}
// ===== end =====

Answer 2

感觉就像做作业。

我认为您的老师希望通过简单的数学测试来显示未启动 InventoryTag 当提供小于或等于 10 的数字时成功。

类似：

// ===== Code from file CallInventoryTag.java =====
public class CallInventoryTag {
   public static void main (String [] args) {
       InventoryTag redSweater = new InventoryTag();
       int sweaterShipment;
       int sweaterInventoryBefore;

       sweaterInventoryBefore = redSweater.getQuantityRemaining();
       sweaterInventoryBefore = 10;
       sweaterShipment = 50;

       System.out.println("Beginning tests.");

       // FIXME add unit test for addInventory
       redSweater.addInventory(sweaterInventoryBefore);
       redSweater.addInventory(sweaterShipment);

       if (sweaterInventoryBefore + sweaterShipment != redSweater.getQuantityRemaining()) {
           System.out.println(" UNIT TEST FAILED: addInventory()");
       }

       System.out.println("Tests complete.");
   }

 }// ===== end =====

测试失败，因为方法 addInventory 中的条件阻止向库存添加 10 个或更少的项目。

Answer 3

您的代码应位于 src/main 以获取源代码，src/test 用于测试。 然后，当您在 package a; 并位于 src/main 中添加类 A 的测试时，您在位于 package a; 的 package a; 中写入 ATest。

在您的示例中，测试类应类似于：

public class CallInventoryTagTest {
   @Test(expected=YourException.class)
   public static void shouldThrowYourExceptionWhenX () {
       //given
       InventoryTag redSweater = new InventoryTag();
       int sweaterShipmen=25;
       int sweaterInventoryBefore;
       //when
       // that's what you need to write after your FIXME
       sweaterInventoryBefore = redSweater.getQuantityRemaining(); 
       redSweater.addInventory(sweaterShipmen)  //calling addinventor with parameter sweaterShipment
       //then
       fail("should throw an error because of X");
   }

 }