Hamcrest比较收藏品

Question

我想比较2个列表:

assertThat(actual.getList(), is(Matchers.containsInAnyOrder(expectedList)));

但想法

java: no suitable method found for assertThat(java.util.List<Agent>,org.hamcrest.Matcher<java.lang.Iterable<? extends model.Agents>>)
method org.junit.Assert.<T>assertThat(T,org.hamcrest.Matcher<T>) is not applicable
  (no instance(s) of type variable(s) T exist so that argument type org.hamcrest.Matcher<java.lang.Iterable<? extends model.Agents>> conforms to formal parameter type org.hamcrest.Matcher<T>)
method org.junit.Assert.<T>assertThat(java.lang.String,T,org.hamcrest.Matcher<T>) is not applicable
  (cannot instantiate from arguments because actual and formal argument lists differ in length)

我该怎么写呢？

Answer 1

如果你想断言两个列表是相同的,不要用Hamcrest复杂化:

assertEquals(expectedList, actual.getList());

如果您真的打算执行顺序不敏感的比较,可以调用containsInAnyOrdervarargs方法并直接提供值:

assertThat(actual.getList(), containsInAnyOrder("item1", "item2"));

(假设你的列表是String,而不是Agent这个例子.)

如果你真的想用a的内容调用相同的方法List:

assertThat(actual.getList(), containsInAnyOrder(expectedList.toArray(new String[expectedList.size()]));

没有这一点,你调用一个参数的方法和创建Matcher一个期望匹配的Iterable,其中每个元素是一个List.这不能用来匹配a List.

也就是说,您无法将a List<Agent>与a 匹配Matcher<Iterable<List<Agent>>,这正是您的代码尝试的内容.

Answer 2

List<Long> actual = Arrays.asList(1L, 2L);
List<Long> expected = Arrays.asList(2L, 1L);
assertThat(actual, containsInAnyOrder(expected.toArray()));

较短版本的@ Joe的答案没有冗余参数.

Answer 3

补充@ Joe的回答:

Hamcrest为您提供了三种匹配列表的主要方法:

contains 检查是否匹配计入订单的所有元素,如果列表具有更多或更少的元素,则它将失败

containsInAnyOrder 检查是否匹配所有元素,如果列表具有更多或更少的元素,则无关紧要,将失败

hasItems 检查指定的对象,如果列表有更多,则无关紧要

hasItem 检查一个对象,如果列表有更多,则无关紧要

所有这些都可以收到一个对象列表和使用equals方法进行比较,或者可以与@borjab提到的其他匹配者混在一起:

assertThat(myList , contains(allOf(hasProperty("id", is(7L)), 
                                   hasProperty("name", is("testName1")),
                                   hasProperty("description", is("testDesc1"))),
                             allOf(hasProperty("id", is(11L)), 
                                   hasProperty("name", is("testName2")),
                                   hasProperty("description", is("testDesc2")))));

http://hamcrest.org/JavaHamcrest/javadoc/1.3/org/hamcrest/Matchers.html#contains(E ...) http://hamcrest.org/JavaHamcrest/javadoc/1.3/org/hamcrest/Matchers.html #containsInAnyOrder(java.util.Collection) http://hamcrest.org/JavaHamcrest/javadoc/1.3/org/hamcrest/Matchers.html#hasItems(T ...)

Answer 4

使用现有的Hamcrest库(从v.2.0.0.0开始),您必须在Collection上使用Collection.toArray()方法才能使用containsInAnyOrder Matcher.更好的是将它作为一个单独的方法添加到org.hamcrest.Matchers:

public static <T> org.hamcrest.Matcher<java.lang.Iterable<? extends T>> containsInAnyOrder(Collection<T> items) {
    return org.hamcrest.collection.IsIterableContainingInAnyOrder.<T>containsInAnyOrder((T[]) items.toArray());
}

实际上我最终将这个方法添加到我的自定义测试库中并使用它来提高我的测试用例的可读性(由于更少的冗长).

Answer 5

对于对象列表，您可能需要这样的东西：

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.contains;
import static org.hamcrest.Matchers.allOf;
import static org.hamcrest.beans.HasPropertyWithValue.hasProperty;
import static org.hamcrest.Matchers.is;

@Test
@SuppressWarnings("unchecked")
public void test_returnsList(){

    arrange();
  
    List<MyBean> myList = act();
    
    assertThat(myList , contains(allOf(hasProperty("id",          is(7L)), 
                                       hasProperty("name",        is("testName1")),
                                       hasProperty("description", is("testDesc1"))),
                                 allOf(hasProperty("id",          is(11L)), 
                                       hasProperty("name",        is("testName2")),
                                       hasProperty("description", is("testDesc2")))));
}

如果您不想检查对象的顺序，请使用containsInAnyOrder 。

PS 任何有助于避免被抑制的警告的帮助将不胜感激。