摩根托规则不应用

Question

我正在使用Mockito编写一个测试柜，在我看来，一个Mockito规则没有得到定义。以下是我的场景。

public class DummyTest {
   private final String[] alphabet= {"a", "b", "c", "d", "e" };
   private final String[] numeric= {"1", "2", "3", "4", "5" };
   AtomicInteger idx;
   String currentAlphabet;
   String currentNumeric;
   int currentIndex;
   Dummy dummyObj;
   private ruleSetUp() {
       dummyObj = Mockito.spy(new Dummy());
        // Rule for rs.next()
         Mockito.doAnswer(new Answer<Boolean>() {
        @Override
        public Boolean answer(InvocationOnMock invocation) throws Throwable {
            currentIndex = idx.getAndIncrement();
            if (alphabet.length > currentIndex) {
                currentAlphabet= alphabet[currentIndex];
                currentNumeric= numeric[currentIndex];
                return true;
            } else
                return false;
        };
    }).when(rs).next();
   // Rule for rs.getInt()
   Mockito.doAnswer(new Answer<Integer>() {
        @Override
        public Integer answer(InvocationOnMock invocation) throws Throwable {
            return idx.get() - 1;
        };
    }).when(rs).getInt(2);
    // Rule for rs.getByte()
    Mockito.doAnswer(new Answer<byte[]>() {
        @Override
        public byte[] answer(InvocationOnMock invocation) throws Throwable {
            return currentNumeric.getBytes(StandardCharsets.UTF_8);
        };
    }).when(rs).getBytes(1);
       Mockito.doReturn(currentAplhabet).when(dummyObj).innerMethod(Mockito.anyInt(), Mockito.anyInt());
  }
  @Test
  public void methodTest(){

       ruleSetUp();
  }
}

我正在测试的方法如下：

class Dummy {
       public void method(int param1) {
          /*   some code  */
          param2 = xyz() ;  // Some mathematical calculation
          while(rs.next()) {
              byte[] strByte = rs.getBytes(1); 
              int number = rs.getInt(2);
              String str= new String(strByte, StandardCharset.UTF-8);
              // TEst Case rule causes below value to be always null
              String alphabet = innerMethod(param1, param2);               
          }
       }
}

在执行此测试方法时，始终发现正在测试的方法中字母的值是无效的。根据电流数的正确值，正确填充了" str"的值。循环还运行正确的次数。

我很困惑为什么不应用Innermethd（）的规则。我没有遇到任何错误，只有填充的值总是无效的，无论循环正在通过的迭代中如何。

你们能指出我出错的地方和解决方案的方法吗？

谢谢

Answer 1

 String currentAlphabet;
 private ruleSetUp() {
   // [snip]
   Mockito.doReturn(currentAlphabet).when(dummyObj).innerMethod(
       Mockito.anyInt(), Mockito.anyInt());
 }

Mockito将每个呼叫的null返回到innerMethod ，因为您正在告诉。尽管每当调用next时设置currentAlphabet，但直到那时才设置任何内容。在称为ruleSetup时，currentAlphabet为null，因此每个呼叫innerMethod的oblito stubs null。

您需要将doReturn与答案相反：

doAnswer(new Answer<String>() {
  @Override public void answer(InvocationOnMock invocation) {
    // This field on the test changes based on other invocations.
    return currentAlphabet;
  }
}).when(dummyObj).innerMethod(anyInt(), anyInt());

作为旁注，因为您要替换多种相关方法的行为，因此为了可读性和易于维护而考虑正常的覆盖：

private DummyObj createDummy() {
  return new DummyObj() {
    private final String[] alphabet= {"a", "b", "c", "d", "e" };
    private final String[] numeric= {"1", "2", "3", "4", "5" };
    AtomicInteger idx;
    String currentAlphabet;
    String currentNumeric;
    int currentIndex;
    @Override public boolean next() { /* ... */ }
    @Override public int nextInt() { /* ... */ }
    @Override public byte nextByte() { /* ... */ }
    @Override public String innerMethod() { /* ... */ }
  };
}