如何将Hamcrest匹配器应用于被测试类的属性

Question

是否有一种方法来构建一个组合Hamcrest匹配器测试对象和这个对象的属性?-伪代码:

both(
  instanceof(MultipleFailureException.class)
).and(
  // pseudo code starts
  adapt(
    new Adapter<MultipleFailureException, Iterable<Throwable>()
    {
      public Iterable<Throwable> getAdapter(MultipleFailureException item)
      {
        return item.getFailures();
      }
    }, 
    // pseudo code ends
    everyItem(instanceOf(IllegalArgumentException.class))
  )
)

背景:我有一个JUnit测试，它在一组动态对象上迭代。每个对象在处理时都会抛出异常。收集异常。测试将以MultipleFailureException结束，该MultipleFailureException包含以下抛出异常的集合:

protected final ExpectedException expectation = ExpectedException.none();
protected final ErrorCollector collector = new ErrorCollector();
@Rule
public RuleChain exceptionRules = RuleChain.outerRule(expectation).around(collector);
@Test
public void testIllegalEnumConstant()
{
  expectation.expect(/* pseudo code from above */);
  for (Object object : ILLEGAL_OBJECTS)
  {
    try
    {
      object.processWithThrow();
    }
    catch (Throwable T)
    {
      collector.addError(T);
    }
  }
}

Answer 1

我想你可能正在寻找hasProperty或hasPropertyWithValue

请看这里的例子:https://theholyjava.wordpress.com/2011/10/15/hasproperty-the-hidden-gem-of-hamcrest-and-assertthat/

另一个我以前工作过的例子;这里我们检查是否有一个Quote方法，getModels()返回PhoneModel的集合，并且集合中的一个项目具有等于LG_ID的属性makeId和等于NEXUS_4_ID的属性modelId。

            assertThat(quote.getModels(),
                            hasItem(Matchers.<PhoneModel> hasProperty("makeId",
                                            equalTo(LG_ID))));
            assertThat(quote.getModels(),
                            hasItem(Matchers.<PhoneModel> hasProperty("modelId",
                                            equalTo(NEXUS_4_ID))));
    }

要使其工作，hamcrest依赖于您采用JavaBean约定。