Java PowerMock whenNew未返回模拟实例
我正试图使用PowerMock来拒绝对Jackson ObjectMapper的调用,但由于某些原因,它不起作用,我怀疑这与当模拟实例在被测试的方法中实例化时,它没有实际提供模拟实例有关 这是一个我们无法真正更改的遗留代码库,因此我们只能使用PowerMock来满足测试覆盖率要求 我有一个类似于以下内容的方法:Java PowerMock whenNew未返回模拟实例,java,unit-testing,powermock,Java,Unit Testing,Powermock,我正试图使用PowerMock来拒绝对Jackson ObjectMapper的调用,但由于某些原因,它不起作用,我怀疑这与当模拟实例在被测试的方法中实例化时,它没有实际提供模拟实例有关 这是一个我们无法真正更改的遗留代码库,因此我们只能使用PowerMock来满足测试覆盖率要求 我有一个类似于以下内容的方法: private void intakeDataFromUrl(URL url) { ObjectMapper mapper = new ObjectMapper(); D
private void intakeDataFromUrl(URL url) {
ObjectMapper mapper = new ObjectMapper();
DataDTO[] dataDtos = mapper.readValue(url, DataDTO[].class)
// other code
}
@Test
public void test_intakeDataFromUrl() {
DataDTO[] data = this.createMockData();
ObjectMapper mapper = mock(ObjectMapper.clas);
whenNew(ObjectMapper.clas)
.withNoArguments()
.thenReturn(mapper);
// mock call to return mocked data
doReturn(data)
.when(mapper, "readValue", any(URL.class), any(DataDTO[].class))
}
在单元测试中,我尝试执行以下操作:
private void intakeDataFromUrl(URL url) {
ObjectMapper mapper = new ObjectMapper();
DataDTO[] dataDtos = mapper.readValue(url, DataDTO[].class)
// other code
}
@Test
public void test_intakeDataFromUrl() {
DataDTO[] data = this.createMockData();
ObjectMapper mapper = mock(ObjectMapper.clas);
whenNew(ObjectMapper.clas)
.withNoArguments()
.thenReturn(mapper);
// mock call to return mocked data
doReturn(data)
.when(mapper, "readValue", any(URL.class), any(DataDTO[].class))
}
但是在被测试的代码中,dataDtos总是空的,然后下一段代码总是失败
编辑:
看起来这一行可能是问题所在,尽管看看其他例子,它应该会起作用
// mock call to return mocked data
doReturn(data)
.when(mapper, "readValue", any(URL.class), any(DataDTO[].class))
我在最后一个参数上也尝试了isA和eq,但没有成功,仍然返回null。以下使用
whenNew
和ObjectMapper
成功:
@RunWith(PowerMockRunner.class)
@PrepareForTest({ObjectMapper.class})
public class WtfTest {
@Test
public void test_intakeDataFromUrl() throws Exception {
String in = "in";
String out = "out";
ObjectMapper mapper = mock(ObjectMapper.class);
PowerMockito.whenNew(ObjectMapper.class)
.withNoArguments()
.thenReturn(mapper);
Mockito.when(mapper.readValue(in, String.class)).thenReturn(out);
assertEquals(out, intakeDataFromUrl(in));
}
private String intakeDataFromUrl(String url) throws IOException {
ObjectMapper mapper = new ObjectMapper();
return mapper.readValue(url, String.class);
}
}
尽管此示例未使用
DataDTO
,但它在其他方面与您的示例一致,并且具有功能性 以下使用whenNew
和ObjectMapper
成功:
@RunWith(PowerMockRunner.class)
@PrepareForTest({ObjectMapper.class})
public class WtfTest {
@Test
public void test_intakeDataFromUrl() throws Exception {
String in = "in";
String out = "out";
ObjectMapper mapper = mock(ObjectMapper.class);
PowerMockito.whenNew(ObjectMapper.class)
.withNoArguments()
.thenReturn(mapper);
Mockito.when(mapper.readValue(in, String.class)).thenReturn(out);
assertEquals(out, intakeDataFromUrl(in));
}
private String intakeDataFromUrl(String url) throws IOException {
ObjectMapper mapper = new ObjectMapper();
return mapper.readValue(url, String.class);
}
}
尽管此示例未使用
DataDTO
,但它在其他方面与您的示例一致,并且具有功能性 你能分享测试类的定义吗?它是用@PrepareForTest
注释的吗?我用真实的代码做了一个例子,因为它不允许共享,但是这个类用@PrepareForTest注释,并且它有ObjectMapper.class以及正在测试的类doReturn
调用是问题所在。应该是Mockito.when(mapper.readValue(…,…)。然后返回(…)代码>。请参阅。您可以共享测试类的定义吗?它是用@PrepareForTest
注释的吗?我用真实的代码做了一个例子,因为它不允许共享,但是这个类用@PrepareForTest注释,并且它有ObjectMapper.class以及正在测试的类doReturn
调用是问题所在。应该是Mockito.when(mapper.readValue(…,…)。然后返回(…)代码>。看见