Junit 无法模拟 class

Question

当我尝试测试一个方法并使用 PowerMock 和 Mockito 模拟其依赖性时遇到问题。我尝试将依赖方法转换为非静态方法并使用@Mock 注释和@InjectMocks 但完全没有结果。

这里是 class 和正在测试的方法：

/* class to be tested */
public class LoginServiceImpl implements LoginService{

   /* method to be tested */
   @Override
   public String createJwt(String subject, String name, String permission, Date datenow)  throws java.io.UnsupportedEncodingException{
       Date expDate = datenow;
       expDate.setTime(datenow.getTime()+(300*1000));  //expiration time = 30 minutes

       String token = jwtUtils.generateJwt(subject, expDate, name, permission);
       return token;
   }
}

这里有我想要模拟的依赖项，但我在模拟时遇到了麻烦：

/* Dependency I cannot mock */
public class JwtUtils {

    public static String generateJwt(String subject, Date date, String name, String scope) throws java.io.UnsupportedEncodingException{
        String jwt = Jwts.builder()
            .setSubject(subject)
            .setExpiration(date)
            .claim("name", name)
            .claim("scope", scope)
            .signWith(
                    SignatureAlgorithm.HS256,
                    "myPersonalSecretKey12345".getBytes("UTF-8")
            )
            .compact();

       return jwt;
   }
}

最后但并非最不重要的一点是，测试 class 的测试方法失败了。不得不说，它甚至没有到达 assert 方法调用，而是在 when().thenResult() 处失败了。我还必须指定我尝试使用 doReturn() 和 any() 作为匹配器，但没有结果。

@RunWith(MockitoJUnitRunner.class)          //to run Mockito
@PrepareForTest({JwtUtils.class})           //powerMock annotations tomock classes containing static methods
public class LoginServiceImplTest {

   @InjectMocks
   LoginServiceImpl loginService;          //System under test (SUT)

   @Test
   public void createJwtTest() throws Exception {

       SimpleDateFormat ft = new SimpleDateFormat("yyyy-MM-dd");
       Date expdate = ft.parse("2040-12-12");
       String jwt = JwtUtils.generateJwt("BDAGPP32E08F205K", expdate, "Pippo Baudo", "conduttore");
       //HERE IT'S WHERE IT FAILS:
       when(JwtUtils.generateJwt("BDAGPP32E08F205K", expdate, "Pippo Baudo", "conduttore")).thenReturn(jwt);

       assertThat(loginService.createJwt("BDAGPP32E08F205K", "Pippo Baudo", "conduttore", expdate), is(jwt));
   }
}

这是 JUnit 和 Mockito 给我的错误：

org.mockito.exceptions.misusing.MissingMethodInvocationException: when() requires an argument which has to be 'a method call on a mock'. For example: when(mock.getArticles()).thenReturn(articles);

Also, this error might show up because: 1. you stub either of: final/private/equals()/hashCode() methods. Those methods cannot be stubbed/verified. Mocking methods declared on non-public parent classes is not supported. 2. inside when() you don't call method on mock but on some other object.

at com.example.bytecode.SpringBootJWT.services.LoginServiceImplTest.createJwtTest1(LoginServiceImplTest.java:114) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.junit.runners.model.FrameworkMethod.runReflectiveCall(FrameworkMethod.java:50) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57) at org.junit.runners.ParentRunner.run(ParentRunner.java:290) at org.junit.runners.ParentRunner.schedule(ParentRunner.java:71) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) at org.junit.runners.ParentRunner.access[=14=]0(ParentRunner.java:58) at org.junit.runners.ParentRunner.evaluate(ParentRunner.java:268) at org.junit.runners.ParentRunner.run(ParentRunner.java:363) at org.mockito.internal.runners.JUnit45AndHigherRunnerImpl.run(JUnit45AndHigherRunnerImpl.java:37) at org.mockito.runners.MockitoJUnitRunner.run(MockitoJUnitRunner.java:62) at org.junit.runner.JUnitCore.run(JUnitCore.java:137) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68) at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47) at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242) at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

Process finished with exit code 255

Answer 1

没有规定 utility classes 中的方法必须是 static!

实际上这是一种不好的做法，因为它会使您的代码高度耦合且不灵活。您替换此依赖项的问题证明了这一点。

因此，与其屈服于你糟糕的设计并使用 PowerMock，你应该通过删除 static 键来应用 控制反转 方法中的单词将 class 的一个实例传递到您的单元中，最好使用 DI 框架 。在那种情况下，您可以使用简单的 Mockito 来模拟该依赖项并且替换它没有问题。

Answer 2

尝试用 @RunWith(PowerMockRunner.class) 替换 @RunWith(MockitoJUnitRunner.class)。据我所知，所有使用 PowerMock 功能的测试都必须是运行和 PowerMockRunner。

Junit 无法模拟 class

Junit cannot Mock a class

java

junit

unit-testing

mocking

stub