单元测试-Junit-Mockit-PowerMock
0. Junit5
1. Junit4
//手动命令行测试
java -cp /usr1/junit:/usr1/cdncms/lib/* org.junit.runner.JUnitCore com.test.DomainServiceTest
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
1.0 执行报错java.lang.VerifyError: Expecting a stackmap frame at branch target 122
增加配置项： windsows-->installJREs-->edit --> VM arguments --> 增加 -noverify
1.1 Junit注解
@BeforeClass 针对所有测试，只执行一次，且必须为static void
@Before： 初始化方法
@Test： 测试方法，在这里可以测试期望异常和超时时间
@After： 释放资源
@AfterClass： 针对所有测试，只执行一次，且必须为static void
@Ignore： 忽略的测试方法
一个单元测试用例执行顺序为： @BeforeClass –> @Before –> @Test –> @After –> @AfterClass
每一个测试方法的调用顺序为： @Before –> @Test –> @After
1.2 Assert类
assertEquals(boolean expected, boolean actual) 检查两个变量或者等式是否平衡
assertFalse(boolean condition) 检查条件是假的
assertNotNull(Object object) 检查对象不是空的
assertNull(Object object) 检查对象是空的
assertTrue(boolean condition) 检查条件为真
fail() 在没有报告的情况下使测试不通过
junit匹配抛出异常
@Test(expected = IllegalArgumentException.class)
public void canVote_throws_IllegalArgumentException_for_zero_age() {.......}
2. Mockito--创建 Mock 对象并且定义它的行为
2.1
a). 静态方法： import static org.mockito.Mockito.*;
b). 验证方法是否调用： verify(test, times(2)).getUniqueId();
2.2 示例
基本用法: （无法对static method和private method进行插桩）
when(cls.methodName(args)).thenReturn(args) //对指定语句进行插桩
when(cls.methodName(args)).thenThrow(Exception) //抛出异常
1、 基本示例
LinkedList mockedList = mock(LinkedList.class);
//插桩
when(mockedList.get(0)).thenReturn("first");
when(mockedList.get(1)).thenThrow(new RuntimeException());
System.out.println(mockedList.get(0)); //输出"first"
System.out.println(mockedList.get(1)); //抛出异常
System.out.println(mockedList.get(999)); //输出 null , 因为get(999)未插桩
2、 插桩时可用 Matcher.anyString()/anyInt() 等进行入参匹配
when(mockedList.get(anyInt())).thenReturn("element");
3、 针对void方法抛出异常
doThrow(new RuntimeException()).when(mockedList).clear();
4、 针对void方法插桩
doNothing().when(spy).clear();
3. PowerMock--插桩，static/final/private
3.1 原理
//两个重要注解 -- 使用ASM生成代理类进行mock
@RunWith(PowerMockRunner.class) //通用配置
@PrepareForTest( { YourClassWithEgStaticMethod.class }) //需要powermock处理的class，static、final、私有方法等功能
1) 例如：去除'final方法的final标识，在静态方法的最前面加入自己的虚拟实现等。
2) 如果mock的是系统类的final/static，PowerMock会修改调用系统类的class文件，以满足mock需求。
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<powermock.version>1.7.1</powermock.version>
</properties>
<dependencies>
<dependency>
<groupId>org.powermock</groupId>
<artifactId>powermock-module-junit4</artifactId>
<version>${powermock.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.powermock</groupId>
<artifactId>powermock-api-mockito</artifactId>
<version>${powermock.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
//通过PowerMock创建一个虚拟对象
InterfaceToMock mock = Powermockito.mock(InterfaceToMock.class)
//value为你想要让这个method返回的值
Powermockito.when(mock.method(Params…)).thenReturn(valueToReturn)
//如果这个方法返回值为空，则上面的写法会报错,可采用下面的写法
Powermockito.when(mock, “methodName”, Object… params).thenReturn(valueToReturn)
// 也可以采用下面的写法，和上面的一样的效果
Powermockito.doReturn(valueToReturn).when(mock, “methodName”, Object… params)
//这样写也行，适合返回值为void的方法
Powermockito.doReturn(valueToReturn).when(mock).methodName(Object… params)
//你也可以让方法抛异常
Powermockito.when(mock.method(Params..)).thenThrow(new OMSException(“oms”))
//你可以让方法每一次返回的结果都不一样,下面的例子第一次正常返回，第二次调用抛异常
Powermockito.when(mock.method(Params..)).thenReturn(valueToReturn).thenThrow(new OMSException(“some Exception”))
//如果方法返回值为void,不能用thenReturn,要用doThing()
Powermockito.doNothing().when(mock.method(Params…))
3.2 示例1-mock static方法
public class IdGenerator {
public static long generateNewId() {
return 0L;
}
}
public class ClassUnderTest {
public long methodToTest() {
final long id = IdGenerator.generateNewId();
return id;
}
}
@RunWith(PowerMockRunner.class)
@PrepareForTest(IdGenerator.class)
public class TestStatic {
@Test
public void testCallInternalInstance() throws Exception {
PowerMockito.mockStatic(IdGenerator.class);
// 在这个测试用例中,当generateNewId()每次被调用时,都会返回15
PowerMockito.when(IdGenerator.generateNewId()).thenReturn(15L);
Assert.assertEquals(15L, new ClassUnderTest().methodToTest());
}
}
3.2 示例2-模拟构造方法
public class ClassUnderTest {
public boolean createDirectoryStructure(String directoryPath) {
File directory = new File(directoryPath);
if (directory.exists()) {
String msg = "\"" + directoryPath + "\" 已经存在.";
throw new IllegalArgumentException(msg);
}
return directory.mkdirs();
}
}
@RunWith(PowerMockRunner.class)
@PrepareForTest(ClassUnderTest.class)
public class TestConstruction {
//模拟构造函数
@Test
public void createDirectoryStructureWhenPathDoesntExist() throws Exception {
final String directoryPath = "seemygod";
//创建File的模拟对象
File directoryMock = mock(File.class);
//在当前测试用例下,当出现new File("seemygod")时,就返回模拟对象
whenNew(File.class).withArguments(directoryPath).thenReturn(directoryMock);
//当调用模拟对象的exists时,返回false
when(directoryMock.exists()).thenReturn(false);
//当调用模拟对象的mkdirs时,返回true
when(directoryMock.mkdirs()).thenReturn(true);
assertTrue(new ClassUnderTest().createDirectoryStructure(directoryPath));
//验证new File(directoryPath); 是否被调用过
verifyNew(File.class).withArguments(directoryPath);
}
}
3.4 用例3-模拟私有以及 Final 方法
public class PrivatePartialMockingExample {
public String methodToTest() {
return methodToMock("input");
}
private String methodToMock(String input) {
return "REAL VALUE = " + input;
}
}
import static org.powermock.api.mockito.PowerMockito.*;
@RunWith(PowerMockRunner.class)
@PrepareForTest(PrivatePartialMockingExample.class)
public class PrivatePartialMockingExampleTest {
@Test
public void demoPrivateMethodMocking() throws Exception {
final String expected = "TEST VALUE";
final String nameOfMethodToMock = "methodToMock";
final String input = "input";
PrivatePartialMockingExample underTest = spy(new PrivatePartialMockingExample());
//模拟私有方法
when(underTest, nameOfMethodToMock, input).thenReturn(expected);
assertEquals(expected, underTest.methodToTest());
verifyPrivate(underTest).invoke(nameOfMethodToMock, input);
}
}
3.5 用例4-mock系统类的静态和final方法
public class ClassUnderTest {
public boolean callSystemFinalMethod(String str) {
return str.isEmpty();
}
public String callSystemStaticMethod(String str) {
return System.getProperty(str);
}
}
$RunWith(PowerMockRunner.class)
public class TestClassUnderTest {
$Test
$PrepareForTest(ClassUnderTest.class)
public void testCallSystemStaticMethod() {
ClassUnderTest underTest = new ClassUnderTest();
PowerMockito.mockStatic(System.class);
PowerMockito.when(System.getProperty("aaa")).thenReturn("bbb");
Assert.assertEquals("bbb", underTest.callJDKStaticMethod("aaa"));
}
}
3.6 用例-PowerMock处理注解
//PushMsgPostProcessorImpl 是要测试的类，它有两个注解注入的类变量如下：
@Resource
private IMsgToUserService msgToUserService;
//则测试类中可以使用下面的方法注入
@Mock
private IMsgToUserService msgToUserService;
@Before
public void setup() {
MockitoAnnotations.initMocks(this);
pushMsgPostProcessor = new PushMsgPostProcessorImpl();
//给注解的private变量塞一个值
ReflectionTestUtils.setField(pushMsgPostProcessor, "msgToUserService", msgToUserService);
}
3.10 模拟异常
3.10.1 抛出异常-不带参数
//PowerMockito.when(IOUtils.xMLReader()).thenThrow(SAXException.class);
public class IOUtils {
public static String xMLReader() throws SAXException {
return "abc";
}
}
3.10.2 抛出异常-待参数的异常
//PowerMockito.doThrow(new SAXException()).when(IOUtils.class);
public class IOUtils {
public static String xMLReader(SAXReader reader) throws SAXException {
System.out.println("IOUtils.xMLReader");
if (null == reader) {
throw new SAXException();
}
return "abc";
}
}
