考虑如下方法签名:
public String myFunction(String abc);
Mockito可以帮助返回与方法接收到的字符串相同的字符串吗?
考虑如下方法签名:
public String myFunction(String abc);
Mockito可以帮助返回与方法接收到的字符串相同的字符串吗?
当前回答
这是一个很老的问题,但我认为仍然相关。此外,接受的答案仅适用于字符串。同时还有Mockito 2.1,一些进口已经改变,所以我想分享我目前的答案:
import static org.mockito.AdditionalAnswers.returnsFirstArg;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.when;
@Mock
private MyClass myClass;
// this will return anything you pass, but it's pretty unrealistic
when(myClass.myFunction(any())).then(returnsFirstArg());
// it is more "life-like" to accept only the right type
when(myClass.myFunction(any(ClassOfArgument.class))).then(returnsFirstArg());
myClass.myFunction如下所示:
public class MyClass {
public ClassOfArgument myFunction(ClassOfArgument argument){
return argument;
}
}
其他回答
这是一个很老的问题,但我认为仍然相关。此外,接受的答案仅适用于字符串。同时还有Mockito 2.1,一些进口已经改变,所以我想分享我目前的答案:
import static org.mockito.AdditionalAnswers.returnsFirstArg;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.when;
@Mock
private MyClass myClass;
// this will return anything you pass, but it's pretty unrealistic
when(myClass.myFunction(any())).then(returnsFirstArg());
// it is more "life-like" to accept only the right type
when(myClass.myFunction(any(ClassOfArgument.class))).then(returnsFirstArg());
myClass.myFunction如下所示:
public class MyClass {
public ClassOfArgument myFunction(ClassOfArgument argument){
return argument;
}
}
我使用了类似的方法(基本上是相同的方法)。有时,让模拟对象返回某些输入的预定义输出是有用的。这是这样的:
private Hashtable<InputObject, OutputObject> table = new Hashtable<InputObject, OutputObject>();
table.put(input1, ouput1);
table.put(input2, ouput2);
...
when(mockObject.method(any(InputObject.class))).thenAnswer(
new Answer<OutputObject>()
{
@Override
public OutputObject answer(final InvocationOnMock invocation) throws Throwable
{
InputObject input = (InputObject) invocation.getArguments()[0];
if (table.containsKey(input))
{
return table.get(input);
}
else
{
return null; // alternatively, you could throw an exception
}
}
}
);
如果您有Mockito 1.9.5或更高版本,有一种新的静态方法可以为您创建Answer对象。你需要写一些像
import static org.mockito.Mockito.when;
import static org.mockito.AdditionalAnswers.returnsFirstArg;
when(myMock.myFunction(anyString())).then(returnsFirstArg());
或替代地
doAnswer(returnsFirstArg()).when(myMock).myFunction(anyString());
注意,returnsFirstArg()方法在AdditionalAnswers类中是静态的,这是Mockito 1.9.5的新特性;所以您需要正确的静态导入。
您可以通过使用ArgumentCaptor实现这一点
假设您有这样的bean函数。
public interface Application {
public String myFunction(String abc);
}
然后在测试课中:
//Use ArgumentCaptor to capture the value
ArgumentCaptor<String> param = ArgumentCaptor.forClass(String.class);
when(mock.myFunction(param.capture())).thenAnswer(new Answer<String>() {
@Override
public String answer(InvocationOnMock invocation) throws Throwable {
return param.getValue();//return the captured value.
}
});
或者,如果你喜欢lambda,只需:
//Use ArgumentCaptor to capture the value
ArgumentCaptor<String> param = ArgumentCaptor.forClass(String.class);
when(mock.myFunction(param.capture()))
.thenAnswer((invocation) -> param.getValue());
摘要:使用argumentcaptor捕获传递的参数。稍后在回答中返回使用getValue捕获的值。
使用Java 8,Steve的答案可以变成
public void testMyFunction() throws Exception {
Application mock = mock(Application.class);
when(mock.myFunction(anyString())).thenAnswer(
invocation -> {
Object[] args = invocation.getArguments();
return args[0];
});
assertEquals("someString", mock.myFunction("someString"));
assertEquals("anotherString", mock.myFunction("anotherString"));
}
编辑:更短:
public void testMyFunction() throws Exception {
Application mock = mock(Application.class);
when(mock.myFunction(anyString())).thenAnswer(
invocation -> invocation.getArgument(0));
assertEquals("someString", mock.myFunction("someString"));
assertEquals("anotherString", mock.myFunction("anotherString"));
}