Question

我有一个Java类，具有以下实现：

    class Some {
      private ArrayList<SomeObject> list = new...

      public void addToList(Long t) {
          SomeObject so = new SomeObject(new Date, t)
          list.add(so)
      } 

      private float fun1(ArrayList<SomeObject> x) {
      //some operations on list "list", 
      //res - result of float calculations based on list "x"
      return res
      }

      public float publicFun() {
         //some other operations on private list "list"
         return fun1(list);
      }

问题是如何使用Mockito，PowerMock或其他测试工具测试函数publicFun()？要运行这个公共函数，我必须模拟私有List，但我该怎么做呢？

Answer 1

在此示例中，由不受欢迎的依赖项引起了几个问题：

1 new Date() 为了解决这个问题，我建议引入新的界面

interface CurrentTimeProvider {
    Date getCurrentDate();
}

实施是显而易见的（我为了简洁而跳过它）

2 Is new ArrayList()

您可以使用自己的界面替换它（仅包含您的方法）需要）
您可以模拟ArrayList本身
您可以使用ArrayList的真实impl并完全测试

结果我们得到这样的结果：

class Some {
  private CurrentTimeProvider timeProvider;
  private ArrayList<SomeObject> list = new ArrayList<SomeObject>();

  public void setTimeProvider(CurrentTimeProvider timeProvider) {
      this.timeProvider = timeProvider;
  }

  public void addToList(Long t) {
      SomeObject so = new SomeObject(timeProvider.getCurrentDate(), t)
      list.add(so)
  } 

  public float publicFun() {
     //some other operations on private list "list"
     return fun1(list);
  }

测试看看这个：

CurrentTimeProvider timeProvider = mock(CurrentTimeProvider.class);
Some some = new Some();
some.setTimeProvider(timeProvider);

when(timeProvider.getCurrentDate).thenReturn(mock(Date.class));

//Invoke you method
some.publicFun();

//Put assert and verify here

使用ArrayList私有成员测试类

1 个答案: