Mockito初体验 |

2月 11, 2018 | Nix.Huang

由于spring boot团队使用Mockito作为mock库，所以果断弃了Jmockit，关于Jmockito的简单使用可以参考
Jmockit Mocking库初体验
本文由javacoder.cn整理，转载注明处理
待测对象和Jmockit Mocking库初体验中的一样

public class ClassUnderTest {
    private DependencyAbc abc;

    public void doSomething() {
        int n = abc.intReturningMethod();
        if (n == 0) {
            System.out.println("from ClassUnderTest.doSomething, n = 0");
            return;
        }
        for (int i = 0; i &lt; n; i++) {
            String s = abc.stringReturningMethod("xyz" + i);
            System.out.println("in ClassUnderTest.doSomething() s=" + s);
        }
    }

    public static  String staticMethod(String str) {
        return str + "staticMethod";
    }

    public void print() {
        System.out.println("from concrete");
    }

    public static interface DependencyAbc {
        public int intReturningMethod();

        public String stringReturningMethod(String p1);
    }
}

public class ClassUnderTest {

private DependencyAbc abc;

public void doSomething() {

int n = abc.intReturningMethod();

if (n == 0) {

System.out.println("from ClassUnderTest.doSomething, n = 0");

return;

}

for (int i = 0; i < n; i++) {

String s = abc.stringReturningMethod("xyz" + i);

System.out.println("in ClassUnderTest.doSomething() s=" + s);

}

public static String staticMethod(String str) {

return str + "staticMethod";

}

public void print() {

System.out.println("from concrete");

}

public static interface DependencyAbc {

public int intReturningMethod();

public String stringReturningMethod(String p1);

}

增加了print()方法便于测试spy partial mocking功能

测试类改动如下：

public class MockitoTest {
    final String msg = "i'm exception";
    @InjectMocks
    private ClassUnderTest cut;
    @Mock
    private ClassUnderTest.DependencyAbc abc;

    AutoCloseable autoCloseable;
    MockedStatic mockedStatic;

    @BeforeEach
    public void before()   {
       autoCloseable = MockitoAnnotations.openMocks(this);
       mockedStatic = mockStatic(ClassUnderTest.class);
    }

    @AfterEach
    public void teardown() throws Exception {
        autoCloseable.close();
        mockedStatic.close();
    }

    @Test
    public void test() {
        //when() verify都是Mockito类的静态方法
        when(abc.intReturningMethod()).thenReturn(3);
        when(abc.stringReturningMethod(anyString()))
                .thenReturn("javacoder.cn", "helloWorld")
                .thenThrow(new RuntimeException(msg));
        String retMsg = null;
        try {
            cut.doSomething();
        } catch (Exception e) {
            retMsg = e.getMessage();
        }
        Assertions.assertEquals(msg, retMsg);
        ArgumentCaptor&lt;String&gt; argument = ArgumentCaptor.forClass(String.class);
        verify(abc, atLeastOnce()).stringReturningMethod(argument.capture());
        Assertions.assertEquals("xyz2", argument.getValue());
    }

    @Test
    public void testSpy() {
        ClassUnderTest _cut = spy(cut);
        doAnswer(invocation-&gt; {
                System.out.println("-------from spy");
                return null;
            }).when(_cut).print();
        _cut.doSomething();
        _cut.print();
    }

    @Test
    public  void testStaticMethod() {
        //需要导入org.mockito:mockito-inline 依赖
        mockedStatic.when(()-&gt;ClassUnderTest.staticMethod(anyString())).thenReturn("mocked");
        String str = ClassUnderTest.staticMethod("hello");
        Assertions.assertEquals(str, "mocked");
    }
}

public class MockitoTest {

final String msg = "i'm exception";

@InjectMocks

private ClassUnderTest cut;

@Mock

private ClassUnderTest.DependencyAbc abc;

AutoCloseable autoCloseable;

MockedStatic mockedStatic;

@BeforeEach

public void before() {

autoCloseable = MockitoAnnotations.openMocks(this);

mockedStatic = mockStatic(ClassUnderTest.class);

}

@AfterEach

public void teardown() throws Exception {

autoCloseable.close();

mockedStatic.close();

}

@Test

public void test() {

//when() verify都是Mockito类的静态方法

when(abc.intReturningMethod()).thenReturn(3);

when(abc.stringReturningMethod(anyString()))

.thenReturn("javacoder.cn", "helloWorld")

.thenThrow(new RuntimeException(msg));

String retMsg = null;

try {

cut.doSomething();

} catch (Exception e) {

retMsg = e.getMessage();

}

Assertions.assertEquals(msg, retMsg);

ArgumentCaptor<String> argument = ArgumentCaptor.forClass(String.class);

verify(abc, atLeastOnce()).stringReturningMethod(argument.capture());

Assertions.assertEquals("xyz2", argument.getValue());

}

@Test

public void testSpy() {

ClassUnderTest _cut = spy(cut);

doAnswer(invocation-> {

System.out.println("-------from spy");

return null;

}).when(_cut).print();

_cut.doSomething();

_cut.print();

}

@Test

public void testStaticMethod() {

//需要导入org.mockito:mockito-inline 依赖

mockedStatic.when(()->ClassUnderTest.staticMethod(anyString())).thenReturn("mocked");

String str = ClassUnderTest.staticMethod("hello");

Assertions.assertEquals(str, "mocked");

}

@InjectMocks 标识需要依赖注入的类
@Mock 标识需要生成mock的类或者接口
触发对注解的处理有三种方式
1）
MockitoAnnotations.openMocks(this);
2）when(abc.intReturningMethod()).thenReturn(3); 表示录入一个期望(Expectation), 当调用intReturningMethod()时返回3
spy(cut);为了生成partial mocking, 录入期望(Expectation)的格式有点不一样。详细的见testSpy()中的doAnswer(Answer).when(_cut).print();语句

Posted in: java基础

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Mockito初体验

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