public String getMongoDBName() throws Exception {
return mongoConnectionDetails.getMongoDatabase().getName();
}
mongoConnectionDetails custom class is Autowired here.
What I tried is
Mock (mongoDboperation);
when(mongoConnectionDetails.getMongoDatabase().getName()).thenReturn("dbName");
String output = mongoDboperation.getMongoDBName();
assertEquals (output, "actualDBname");
But SONAR is still showing it as RED uncovered lines. Please help. Thanks !
You're not getting coverage for this method, because you're running the test with a mock object. This means you are only testing the mock, not the original class.
In general, in the tests for a particular class, you should never mock the class that is being tested. Only mock collaborators of that class (in this case, mongoConnectionDetails.
I want to unit test Java code that calls System.exit(-1) and want it to just do nothing instead of exiting the process. The underlying reason is that otherwise JaCoCo does not work properly and project guidelines want to see that line covered. Changing the tested code is not an option, too. Other calls to System should work normally. PowerMockito 2.0.7 is already used in the project and should be used here, too. My current Java version is 1.8.0_181 on Windows.
I tried with
PowerMockito.spy(System.class);
PowerMockito.doNothing().when(System.class, "exit", ArgumentMatchers.any(int.class));
//here comes the code under test that calls System.exit
It does not seem to work, System.exit seems to exit the process anyway.
How do it get this to work?
I think you should replace both the lines in your sample code
PowerMockito.spy(System.class);
PowerMockito.doNothing.....
to
PowerMockito.mockStatic(System.class);
This change works in my local as System.exit does nothing because of the mock on static method.
Also, I hope you are using PrepareForTest annotation
#PrepareForTest(CLASS_UNDER_TEST)
The spy method is to call real methods and have some wrapper around the non-static methods. Since you need a mock for static methods, mockStatic method should be used instead.
Update 1
The PowerMockito mockStatic method by default creates mock for all the static methods within the class. I don't have any clean solution. But, I can suggest a solution which looks ugly but does what is needed i.e only mock specific static method and remaining methods are invoking real methods. PoweMockito's mockStatic method is internally calling DefaultMockCreator to mock the static methods.
#RunWith(PowerMockRunner.class)
public class StaticTest {
#Test
public void testMethod() throws Exception {
// Get static methods for which mock is needed
Method exitMethod = System.class.getMethod("exit", int.class);
Method[] methodsToMock = new Method[] {exitMethod};
// Create mock for only those static methods
DefaultMockCreator.mock(System.class, true, false, null, null, methodsToMock);
System.exit(-1); // This will be mocked
System.out.println(System.currentTimeMillis()); // This will call up real methods
}
}
As per the PowerMockito documentation, the right way to call static void method is -
PowerMockito.mockStatic(SomeClass.class);
PowerMockito.doNothing().when(SomeClass.class);
SomeClass.someVoidMethod();
Reference - https://github.com/powermock/powermock/wiki/Mockito#how-to-stub-void-static-method-to-throw-exception
This should create the mock behaviour for the specific static void method. Unfortunately, this doesn't work for System Class because System class is final. Had it been not final, this would have worked. I tried it and I got this exception -
org.mockito.exceptions.base.MockitoException:
Cannot mock/spy class java.lang.System
Mockito cannot mock/spy because :
- final class
Code -
#Test
public void testMethod() throws Exception {
PowerMockito.mockStatic(System.class);
PowerMockito.doNothing().when(System.class);
System.exit(-1); // mockito error coming here
System.exit(-1);
System.currentTimeMillis();
}
private void mockStorageServiceFactory(StorageGroupService storageGroupService)
throws StorageServiceException {
PowerMockito.mockStatic(StorageServiceFactory.class);
PowerMockito.when(StorageServiceFactory.getContainerNameForPartner(anyLong()))
.thenReturn("dummyName");
}
Actual method is getting called at 3rd line (when().thenReturn()).
I have already added #RunWith(PowerMockRunner.class) and #PrepareForTest annotations.
Why actual method is called? I tried PowerMockito.doReturn also, but getting same issue.
Sorry, I was running the test case from main method. When i ran it as JUNIT, it is working.
I'm using Mockito 1.9.0. I want mock the behaviour for a single method of a class in a JUnit test, so I have
final MyClass myClassSpy = Mockito.spy(myInstance);
Mockito.when(myClassSpy.method1()).thenReturn(myResults);
The problem is, in the second line, myClassSpy.method1() is actually getting called, resulting in an exception. The only reason I'm using mocks is so that later, whenever myClassSpy.method1() is called, the real method won't be called and the myResults object will be returned.
MyClass is an interface and myInstance is an implementation of that, if that matters.
What do I need to do to correct this spying behaviour?
Let me quote the official documentation:
Important gotcha on spying real objects!
Sometimes it's impossible to use when(Object) for stubbing spies. Example:
List list = new LinkedList();
List spy = spy(list);
// Impossible: real method is called so spy.get(0) throws IndexOutOfBoundsException (the list is yet empty)
when(spy.get(0)).thenReturn("foo");
// You have to use doReturn() for stubbing
doReturn("foo").when(spy).get(0);
In your case it goes something like:
doReturn(resultsIWant).when(myClassSpy).method1();
In my case, using Mockito 2.0, I had to change all the any() parameters to nullable() in order to stub the real call.
My case was different from the accepted answer. I was trying to mock a package-private method for an instance that did not live in that package
package common;
public class Animal {
void packageProtected();
}
package instances;
class Dog extends Animal { }
and the test classes
package common;
public abstract class AnimalTest<T extends Animal> {
#Before
setup(){
doNothing().when(getInstance()).packageProtected();
}
abstract T getInstance();
}
package instances;
class DogTest extends AnimalTest<Dog> {
Dog getInstance(){
return spy(new Dog());
}
#Test
public void myTest(){}
}
The compilation is correct, but when it tries to setup the test, it invokes the real method instead.
Declaring the method protected or public fixes the issue, tho it's not a clean solution.
The answer by Tomasz Nurkiewicz appears not to tell the whole story!
NB Mockito version: 1.10.19.
I am very much a Mockito newb, so can't explain the following behaviour: if there's an expert out there who can improve this answer, please feel free.
The method in question here, getContentStringValue, is NOT final and NOT static.
This line does call the original method getContentStringValue:
doReturn( "dummy" ).when( im ).getContentStringValue( anyInt(), isA( ScoreDoc.class ));
This line does not call the original method getContentStringValue:
doReturn( "dummy" ).when( im ).getContentStringValue( anyInt(), any( ScoreDoc.class ));
For reasons which I can't answer, using isA() causes the intended (?) "do not call method" behaviour of doReturn to fail.
Let's look at the method signatures involved here: they are both static methods of Matchers. Both are said by the Javadoc to return null, which is a little difficult to get your head around in itself. Presumably the Class object passed as the parameter is examined but the result either never calculated or discarded. Given that null can stand for any class and that you are hoping for the mocked method not to be called, couldn't the signatures of isA( ... ) and any( ... ) just return null rather than a generic parameter* <T>?
Anyway:
public static <T> T isA(java.lang.Class<T> clazz)
public static <T> T any(java.lang.Class<T> clazz)
The API documentation does not give any clue about this. It also seems to say the need for such "do not call method" behaviour is "very rare". Personally I use this technique all the time: typically I find that mocking involves a few lines which "set the scene" ... followed by calling a method which then "plays out" the scene in the mock context which you have staged... and while you are setting up the scenery and the props the last thing you want is for the actors to enter stage left and start acting their hearts out...
But this is way beyond my pay grade... I invite explanations from any passing Mockito high priests...
* is "generic parameter" the right term?
One more possible scenario which may causing issues with spies is when you're testing spring beans (with spring test framework) or some other framework that is proxing your objects during test.
Example
#Autowired
private MonitoringDocumentsRepository repository
void test(){
repository = Mockito.spy(repository)
Mockito.doReturn(docs1, docs2)
.when(repository).findMonitoringDocuments(Mockito.nullable(MonitoringDocumentSearchRequest.class));
}
In above code both Spring and Mockito will try to proxy your MonitoringDocumentsRepository object, but Spring will be first, which will cause real call of findMonitoringDocuments method. If we debug our code just after putting a spy on repository object it will look like this inside debugger:
repository = MonitoringDocumentsRepository$$EnhancerBySpringCGLIB$$MockitoMock$
#SpyBean to the rescue
If instead #Autowired annotation we use #SpyBean annotation, we will solve above problem, the SpyBean annotation will also inject repository object but it will be firstly proxied by Mockito and will look like this inside debugger
repository = MonitoringDocumentsRepository$$MockitoMock$$EnhancerBySpringCGLIB$
and here is the code:
#SpyBean
private MonitoringDocumentsRepository repository
void test(){
Mockito.doReturn(docs1, docs2)
.when(repository).findMonitoringDocuments(Mockito.nullable(MonitoringDocumentSearchRequest.class));
}
Important gotcha on spying real objects
When stubbing a method using spies , please use doReturn() family of methods.
when(Object) would result in calling the actual method that can throw exceptions.
List spy = spy(new LinkedList());
//Incorrect , spy.get() will throw IndexOutOfBoundsException
when(spy.get(0)).thenReturn("foo");
//You have to use doReturn() for stubbing
doReturn("foo").when(spy).get(0);
I've found yet another reason for spy to call the original method.
Someone had the idea to mock a final class, and found about MockMaker:
As this works differently to our current mechanism and this one has different limitations and as we want to gather experience and user feedback, this feature had to be explicitly activated to be available ; it can be done via the mockito extension mechanism by creating the file src/test/resources/mockito-extensions/org.mockito.plugins.MockMaker containing a single line: mock-maker-inline
Source: https://github.com/mockito/mockito/wiki/What%27s-new-in-Mockito-2#mock-the-unmockable-opt-in-mocking-of-final-classesmethods
After I merged and brought that file to my machine, my tests failed.
I just had to remove the line (or the file), and spy() worked.
One way to make sure a method from a class is not called is to override the method with a dummy.
WebFormCreatorActivity activity = spy(new WebFormCreatorActivity(clientFactory) {//spy(new WebFormCreatorActivity(clientFactory));
#Override
public void select(TreeItem i) {
log.debug("SELECT");
};
});
As mentioned in some of the comments, my method was "static" (though being called on by an instance of the class)
public class A {
static void myMethod() {...}
}
A instance = spy(new A());
verify(instance).myMethod(); // still calls the original method because it's static
Work around was make an instance method or upgrade Mockito to a newer version with some config: https://stackoverflow.com/a/62860455/32453
Bit late to the party but above solutions did not work for me , so sharing my 0.02$
Mokcito version: 1.10.19
MyClass.java
private int handleAction(List<String> argList, String action)
Test.java
MyClass spy = PowerMockito.spy(new MyClass());
Following did NOT work for me (actual method was being called):
1.
doReturn(0).when(spy , "handleAction", ListUtils.EMPTY_LIST, new String());
2.
doReturn(0).when(spy , "handleAction", any(), anyString());
3.
doReturn(0).when(spy , "handleAction", null, null);
Following WORKED:
doReturn(0).when(spy , "handleAction", any(List.class), anyString());
I've created the following test method where I mock Settings.Secure and stub the getString method of that class.
#Test
public void testIsDevicePostOwner() throws Exception {
String mockDeviceId = "2c3977ad-0867-49d6-aad8-c2762f373551";
Post mockedPost = mock(Post.class);
Settings.Secure mockedSecure = mock(Settings.Secure.class);
ContentResolver mockContentResolver = mock(ContentResolver.class);
when(mockedSecure.getString(mockContentResolver, Settings.Secure.ANDROID_ID)).thenReturn(mockDeviceId);
}
When I run the test I get the following error:
java.lang.RuntimeException: Method getString in android.provider.Settings$Secure not mocked.
Does anybody have any ideas?
If you want to mock an static method, use PowerMock
You'll need to run with PowerMockRunner and Prepare the class for test:
#PrepareForTest({Settings.Secure.class})
For mocking the object you need to:
PowerMockito.mockStatic(Settings.Secure.class);
Then you could try:
when(Settings.Secure.getString(mockContentResolver, Settings.Secure.ANDROID_ID)).thenReturn(mockDeviceId);
Finally, you could test:
verifyStatic();
Try adding
testOptions {
unitTests.returnDefaultValues = true
}
in your build.gradle
More info here http://tools.android.com/tech-docs/unit-testing-support
Settings.Secure.getString is a static method, so mock(Settings.Secure.class) won't mock it. Even subclassing Settings.Secure and creating your own static getString won't help here.
I'm not sure if there's any reflection magic that can help you out in this case; none comes to mind.