java - 如何使用通配符模拟泛型方法的行为

Question

我正在使用 EasyMock (3.2)。我想基于 Spring Security 为我的部分安全系统编写测试。我想模拟 Authentication 以便它返回空的权限列表。其方法声明如下:

 Collection<? extends GrantedAuthority> getAuthorities();

所以我写了一个测试:

Authentication authentication = createMock(Authentication.class);
Collection<? extends GrantedAuthority> authorities = Collections.emptyList();
expect(authentication.getAuthorities()).andReturn(authorities);

但是编译器提示 andReturn 上的第三行调用:

The method andReturn(Collection<capture#1-of ? extends GrantedAuthority>) in the type IExpectationSetters<Collection<capture#1-of ? extends GrantedAuthority>> is not applicable for the arguments (Collection<capture#2-of ? extends GrantedAuthority>

我做错了什么？

---

更新:

当我更改 authorities 的声明时到:

Collection<GrantedAuthority> authorities = Collections.emptyList();

按照提示，还是编译不通过，但是报错有点不同:

The method andReturn(Collection<capture#1-of ? extends GrantedAuthority>) in the type IExpectationSetters<Collection<capture#1-of ? extends GrantedAuthority>> is not applicable for the arguments (Collection<GrantedAuthority>)

我确保 GrantedAuthority在两个声明中实际上是相同的 - org.springframework.security.core.GrantedAuthority .

Answer 1

从集合声明中删除项目类型，您会收到警告，但测试会正常进行。

@Test
public void testFoo()
    {
    // setup
    Authentication mockAuthentication = createMock(Authentication.class);
    Collection authorities = Collections.emptyList();
    expect(mockAuthentication.getAuthorities()).andReturn(authorities);

    // exercise
    EasyMock.replay(mockAuthentication);
    Collection<? extends GrantedAuthority> retAuth = mockAuthentication.getAuthorities();

    // verify
    EasyMock.verify(mockAuthentication);
    assertEquals(authorities, retAuth);
    }