Mock inner method which uses local variable as paramenter - java

I've recently started using Mockito 3 + Junit 5 + Spring 5 and I'm writing some example tests in order to understand how Mockito works. I have a question about inner calls. So, I have a spring component A in which is injected some DAO component someObjectDAO. The A class:
#Component("aClass")
public class A {
#Autowired
private ObjectDAO someObjectDAO;
public Long countRecords() {
ObjectSearchCriteria search = new ObjectSearchCriteria();
return someObjectDAO.count(search);
}
}
I want to test A's countRecords method. I've mocked and injected someObjectDAO like this:
#ExtendWith(MockitoExtension.class)
#ContextConfiguration("contextConfFileSomewhere")
public class ATest {
#Mock
ObjectDAO someObjectDAOMock;
#InjectMocks
A aComponent;
#Test
void testCount() {
ObjectSearchCriteria search = Mockito.mock(ObjectSearchCriteria.class);
Mockito.when(someObjectDAOMock.count(search)).thenReturn(1L);
Assertion.assertEquals(1L, aComponent.countRecords());
}
}
But this way is incorrect, in fact PotentialStubbingProblem is raised.
org.mockito.exceptions.misusing.PotentialStubbingProblem:
Strict stubbing argument mismatch. Please check:
- this invocation of 'count' method:
someObjectDAO.count(
com.example.java.ObjectSearchCriteria#45cc6b13
);
-> at com.example.java.A.countRecords()
- has following stubbing(s) with different arguments:
1. someObjectDAOMock.count(
Mock for ObjectSearchCriteria, hashCode: 204078646
);
Typically, stubbing argument mismatch indicates user mistake when writing tests.
Mockito fails early so that you can debug potential problem easily.
However, there are legit scenarios when this exception generates false negative signal:
- stubbing the same method multiple times using 'given().will()' or 'when().then()' API
Please use 'will().given()' or 'doReturn().when()' API for stubbing.
- stubbed method is intentionally invoked with different arguments by code under test
Please use default or 'silent' JUnit Rule (equivalent of Strictness.LENIENT).
For more information see javadoc for PotentialStubbingProblem class.
If I understand correctly the exception indicates that I'm passing an object different from the actual object used in the code under test, right?
So, how can I mock a inner method which uses a local variable as parameter?

You want to mock the call to ObjectDAO.count which has parameters. Instead of passing an instance of the expected parameter as an argument, you should use an argument matcher:
Mockito.when(someObjectDAOMock.count(Mockito.any(ObjectSearchCriteria.class)))
.thenReturn(1L);
Edit: You should probably never even want to "mock a local variable". Your goal is to test the system under test (countRecords method) without knowing implementation details. All you can do is mock the dependencies.

Related

Mockito verify still fails on using all Matchers

I am recently writing a JUnit test and I acknowledged that Mockito either needs all Raw values or using all Matchers but I find the following case still fails with all Matchers, error message is:
Invalid use of argument matchers!
0 matchers expected, 1 recorded:
I tested a little bit and it looks like something to do with using a stub method as value for the eq() Matcher. See example below:
I have a Class A very simple
public class A {
public void testMockitoMatcher(double a, String b){
}
}
Here is my test case
import org.junit.Test;
import static org.mockito.Mockito.*;
public class SomeUnitTest {
private A mockA = mock(A.class);
#Test
public void allMatchersDoesntWork() {
Object mockObject = mock(Object.class);
String someString = "Just some mocked String value to return";
when(mockObject.toString()).thenReturn(someString);
mockA.testMockitoMatcher(1312d, mockObject.toString());
verify(mockA, times(1)).testMockitoMatcher(anyDouble(), eq(someString)); //<- This works
verify(mockA, times(1)).testMockitoMatcher(anyDouble(), eq(mockObject.toString())); //<- This doesn't by using stub method toString() to return the String value as param to eq()
}
}
I also verified by using debug at 2nd verify statement that mockObject.toString() can still return the stubbed value for me. Also both verify use all Matchers, why mockito still gives me only 1 Matchers recorded instead of 2 at the 2nd verify?
Thanks!
Mockito expects your tests to be in three stages.
You set things up for the test, including stubbing any methods that need to be stubbed (the "arrange" stage).
You run the actual method that you're trying to test (the "act" stage).
You make assertions about the output of the test, possibly including verifying which methods got called on your mocks (the "assert" stage).
You need to do these three things, in this sequence, because Mockito tracks whether you're stubbing, verifying or whatever. It also has its own internal stack which stores Matchers, for use in stubbing or verification.
In your second verify call in your example, the call to anyDouble() puts the Matcher onto the stack. But this creates an invalid state for the call to mockObject.toString().
Don't do this. Once you're ready to run your assertions and verifications, you shouldn't be making any more calls to stubbed methods. Keep the "arrange", "act" and "assert" stages of each test entirely separate from each other.

How to set Mock to have a default behavior and can override it in some test

I want to mock a dependency and return a default value in most test cases since most of them should not care about the values returned but there are some certain cases like I would like to test like the dependency returns some weird values or just throw. So I am modeling it in this way. Most cases, it should return a nice and valid value.
Test Setup which return the 20L by default for all test classes.
Dependency dependency = Mockito.mock(Dependency.class);
when(dependency.returnSomeVal()).thenReturn(20L);
In a specific test cases class, I would like to override the behavior like below:
when(dependency.returnSomeVal()).thenThrow(); //failure cases
when(dependency.returnSomeVal()).thenReturn(Weird_Val); //failure cases
But I don't find a good solution to override the existing behavior? Any idea?
You can reset the mock and add behavior. In the test, do
Mockito.reset(dependency);
when(dependency.returnSomeVal()).thenThrow(); //failure cases
when(dependency.returnSomeVal()).thenReturn(Weird_Val); //failure cases
Resetting will remove all mocked behavior on this class though. If you want to remock only some methods, then you have to create the mock from scratch.
I ended using myself this pattern to mock a bunch of methods of a class providing configurations.
In a #Before method I setup a bunch of stubs for a mocked object that provide a correct configuration for each test. Afterwards, in each test it was extremely convenient to only override one of those stubs to provide a different configuration and test a different error case.
I think the response from Hari Menon is correct but it somehow defeats the purpose explained in the question. If the mock is reset, all the stubs would need to be added again, making this pattern very confusing (it would be better to not use any overriding than using reset in this case, the code would be way more straightforward).
The comments added to the question provide indeed an indirect answer on how to achieve this, and why it works, but it took me a bit to get it working.
In spite of one of the comments, I made everything work by using in my #Before fixture when().thenReturn() and overriding the concrete stub with doReturn().when()
Example:
public class WorkerTest {
private ConfigProvider mockedConfigProvider = mock(ConfigProvider.class);
#Before
public void setup() {
// Setup stubs with a correct config
when(mockedConfigProvider.getValue("property1")).thenReturn("value1");
when(mockedConfigProvider.getValue("property2")).thenReturn("value2");
when(mockedConfigProvider.getValue("property3")).thenReturn("value3");
when(mockedConfigProvider.getValue("property4")).thenReturn("value4");
}
#Test
public void test_GoodConfig(){
// The config object gets injected in the test worker
Worker testWorker = new Worker(mockedConfigProvider);
// testWorker.execute() returns true if everything went well
assertTrue(testWorker.execute());
}
#Test
public void test_BadConfigProp1(){
// Test now with a broken 'property1', overriding that stub.
doReturn(null).when(mockedConfigProvider).getValue("property1");
Worker testWorker = new Worker(mockedConfigProvider);
// testWorker.execute() returns false if there is a problem.
assertFalse(testWorker.execute());
}
#Test
public void test_BadConfigProp2(){
// This test needs to only override the result of property2
doReturn("crazy result").when(mockedConfigProvider).getValue("property2");
...
}

How to resolve Unneccessary Stubbing exception

My Code is as below,
#RunWith(MockitoJUnitRunner.class)
public class MyClass {
private static final String code ="Test";
#Mock
private MyClassDAO dao;
#InjectMocks
private MyClassService Service = new MyClassServiceImpl();
#Test
public void testDoSearch() throws Exception {
final String METHOD_NAME = logger.getName().concat(".testDoSearchEcRcfInspections()");
CriteriaDTO dto = new CriteriaDTO();
dto.setCode(code);
inspectionService.searchEcRcfInspections(dto);
List<SearchCriteriaDTO> summaryList = new ArrayList<SearchCriteriaDTO>();
inspectionsSummaryList.add(dto);
when(dao.doSearch(dto)).thenReturn(inspectionsSummaryList);//got error in this line
verify(dao).doSearchInspections(dto);
}
}
I am getting below exception
org.mockito.exceptions.misusing.UnnecessaryStubbingException:
Unnecessary stubbings detected in test class: Test
Clean & maintainable test code requires zero unnecessary code.
Following stubbings are unnecessary (click to navigate to relevant line of code):
1. -> at service.Test.testDoSearch(Test.java:72)
Please remove unnecessary stubbings or use 'silent' option. More info: javadoc for UnnecessaryStubbingException class.
at org.mockito.internal.exceptions.Reporter.formatUnncessaryStubbingException(Reporter.java:838)
at org.mockito.internal.junit.UnnecessaryStubbingsReporter.validateUnusedStubs(UnnecessaryStubbingsReporter.java:34)
at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:49)
at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:103)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Please help me how to resolve
At first you should check your test logic. Usually there are 3 cases. First, you are mocking the wrong method (you made a typo or someone changed tested code so that mocked method is no longer used). Second, your test is failing before this method is called. Third, your logic falls in wrong if/switch branch somewhere in the code so that mocked method is not called.
If this is the first case you always want to change the mocked method for the one used in the code. With the second and the third it depends. Usually you should just delete this mock if it has no use. But sometimes there are certain cases in parametrized tests, which should take this different path or fail earlier. Then you can split this test into two or more separate ones but that's not always good looking. 3 test methods with possibly 3 arguments providers can make your test look unreadable. In that case for JUnit 4 you silent this exception with either
#RunWith(MockitoJUnitRunner.Silent.class)
annotation or if you are using rule approach
#Rule
public MockitoRule rule = MockitoJUnit.rule().strictness(Strictness.LENIENT);
or (the same behaviour)
#Rule
public MockitoRule rule = MockitoJUnit.rule().silent();
For JUnit 5 tests you can silence this exception using this annotation provided in mockito-junit-jupiter package:
#ExtendWith(MockitoExtension.class)
#MockitoSettings(strictness = Strictness.LENIENT)
class JUnit5MockitoTest {
}
Replace #RunWith(MockitoJUnitRunner.class) with #RunWith(MockitoJUnitRunner.Silent.class).
For me neither the #Rule nor the #RunWith(MockitoJUnitRunner.Silent.class) suggestions worked. It was a legacy project where we upgraded to mockito-core 2.23.0.
We could get rid of the UnnecessaryStubbingException by using:
Mockito.lenient().when(mockedService.getUserById(any())).thenReturn(new User());
instead of:
when(mockedService.getUserById(any())).thenReturn(new User());
Needless to say that you should rather look at the test code, but we needed to get the stuff compiled and the tests running first of all ;)
Silent is not a solution. You need fix your mock in your test. See official documentation here.
Unnecessary stubs are stubbed method calls that were never realized during test execution (see also MockitoHint), example:
//code under test:
...
String result = translator.translate("one")
...
//test:
...
when(translator.translate("one")).thenReturn("jeden"); // <- stubbing realized during code execution
when(translator.translate("two")).thenReturn("dwa"); // <- stubbing never realized
...
Notice that one of the stubbed methods were never realized in the code under test, during test execution. The stray stubbing might be an oversight of the developer, the artifact of copy-paste or the effect not understanding the test/code. Either way, the developer ends up with unnecessary test code. In order to keep the codebase clean & maintainable it is necessary to remove unnecessary code. Otherwise tests are harder to read and reason about.
To find out more about detecting unused stubbings see MockitoHint.
when(dao.doSearch(dto)).thenReturn(inspectionsSummaryList);//got error in this line
verify(dao).doSearchInspections(dto);
The when here configures your mock to do something. However, you donot use this mock in any way anymore after this line (apart from doing a verify). Mockito warns you that the when line therefore is pointless. Perhaps you made a logic error?
Replace
#RunWith(MockitoJUnitRunner.class)
with
#RunWith(MockitoJUnitRunner.Silent.class)
or remove #RunWith(MockitoJUnitRunner.class)
or just comment out the unwanted mocking calls (shown as unauthorised stubbing).
This was already pointed out in this comment, but I think that's too easy to overlook: You may run into an UnnecessaryStubbingException if you simply convert a JUnit 4 test class to a JUnit 5 test class by replacing an existing #Before with #BeforeEach, and if you perform some stubbing in that setup method that is not realized by at least one of the test cases.
This Mockito thread has more information on that, basically there is a subtle difference in the test execution between #Before and #BeforeEach. With #Before, it was sufficient if any test case realized the stubbings, with #BeforeEach, all cases would have to.
If you don't want to break up the setup of #BeforeEach into many small bits (as the comment cited above rightly points out), there's another option still instead of activating the lenient mode for the whole test class: you can merely make those stubbings in the #BeforeEach method lenient individually using lenient().
As others pointed out it is usually the simplest to remove the line that is unnecessarily stubbing a method call.
In my case it was in a #BeforeEach and it was relevant most of the time. In the only test where that method was not used I reset the mock, e.g.:
myMock.reset()
Hope this helps others with the same problem.
(Note that if there are multiple mocked calls on the same mock this could be inconvenient as well since you'll have to mock all the other methods except the one that isn't called.)
Looking at a part of your stack trace it looks like you are stubbing the dao.doSearch() elsewhere. More like repeatedly creating the stubs of the same method.
Following stubbings are unnecessary (click to navigate to relevant line of code):
1. -> at service.Test.testDoSearch(Test.java:72)
Please remove unnecessary stubbings or use 'silent' option. More info: javadoc for UnnecessaryStubbingException class.
Consider the below Test Class for example:
#RunWith(MockitoJUnitRunner.class)
public class SomeTest {
#Mock
Service1 svc1Mock1;
#Mock
Service2 svc2Mock2;
#InjectMock
TestClass class;
//Assume you have many dependencies and you want to set up all the stubs
//in one place assuming that all your tests need these stubs.
//I know that any initialization code for the test can/should be in a
//#Before method. Lets assume there is another method just to create
//your stubs.
public void setUpRequiredStubs() {
when(svc1Mock1.someMethod(any(), any())).thenReturn(something));
when(svc2Mock2.someOtherMethod(any())).thenReturn(somethingElse);
}
#Test
public void methodUnderTest_StateUnderTest_ExpectedBehavior() {
// You forget that you defined the stub for svcMock1.someMethod or
//thought you could redefine it. Well you cannot. That's going to be
//a problem and would throw your UnnecessaryStubbingException.
when(svc1Mock1.someMethod(any(),any())).thenReturn(anyThing);//ERROR!
setUpRequiredStubs();
}
}
I would rather considering refactoring your tests to stub where necessary.
Well, In my case Mockito error was telling me to call the actual method after the when or whenever stub. Since we were not invoking the conditions that we just mocked, Mockito was reporting that as unnecessary stubs or code.
Here is what it was like when the error was coming :
#Test
fun `should return error when item list is empty for getStockAvailability`() {
doAnswer(
Answer<Void> { invocation ->
val callback =
invocation.arguments[1] as GetStockApiCallback<StockResultViewState.Idle, StockResultViewState.Error>
callback.onApiCallError(stockResultViewStateError)
null
}
).whenever(stockViewModelTest)
.getStockAvailability(listOf(), getStocksApiCallBack)
}
then I just called the actual method mentioned in when statement to mock the method.
changes done is as below
stockViewModelTest.getStockAvailability(listOf(), getStocksApiCallBack)
#Test
fun `should return error when item list is empty for getStockAvailability`() {
doAnswer(
Answer<Void> { invocation ->
val callback =
invocation.arguments[1] as GetStockApiCallback<StockResultViewState.Idle, StockResultViewState.Error>
callback.onApiCallError(stockResultViewStateError)
null
}
).whenever(stockViewModelTest)
.getStockAvailability(listOf(), getStocksApiCallBack)
//called the actual method here
stockViewModelTest.getStockAvailability(listOf(), getStocksApiCallBack)
}
it's working now.
If you're using this style instead:
#Rule
public MockitoRule rule = MockitoJUnit.rule().strictness(Strictness.STRICT_STUBS);
replace it with:
#Rule
public MockitoRule rule = MockitoJUnit.rule().silent();
I had UnnecessaryStubbingException when I tried to use the when methods on a Spy object.
Mockito.lenient() silenced the exception but the test results were not correct.
In case of Spy objects, one has to call the methods directly.
#ExtendWith(MockitoExtension.class)
#RunWith(JUnitPlatform.class)
class ArithmTest {
#Spy
private Arithm arithm;
#Test
void testAddition() {
int res = arithm.add(2, 5);
// doReturn(7).when(arithm).add(2, 5);
assertEquals(res, 7);
}
}
In case of a large project, it's difficult to fix each of these exceptions. At the same time, using Silent is not advised. I have written a script to remove all the unnecessary stubbings given a list of them.
https://gist.github.com/cueo/da1ca49e92679ac49f808c7ef594e75b
We just need to copy-paste the mvn output and write the list of these exceptions using regex and let the script take care of the rest.
If you use any() when mocking, you have to relpace #RunWith(MockitoJUnitRunner.class) with
#RunWith(MockitoJUnitRunner.Silent.class).

Using #Spy #InjectMocks for the same service. Mockito calls original method [duplicate]

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 AnimalĀ {
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());

Declaring Jmockit mock parameters on #BeforeMethod of TestNG

I've been testing my code behavior using TestNG and JMockit for a while now and I have had no specific issue with their combination. Today I came across a situation where I needed to mock one of my internal dependencies, in the so called, type wide manner and I did not need to keep that mock around since none of the test cases dealt with it directly while they counted on the mocked version functionality. So, naturally, I put the mocking logic in my #BeforeMethod. Here is a sample:
public class SampleTest
{
#Mocked
#Cascading
private InnerDependency dependency;
#BeforeMethod
public void beforeMethod()
{
new NonStrictExpectations()
{
{
dependency.getOutputStream((String)any);
result = new Delegate<OutputStream>()
{
public OutputStream getOutputStream(String url)
{
return null;
}
};
}
};
}
#Test
public void testNormalOperation()
{
// The test whose desired behavior depends on dependency being mocked out
// ..
}
}
But, since my tests do not care about the mocked dependency explicitly, I'm not willing to declare it as a test class field, unlike what is done above. To my knowledge of JMockit The only options remaining would be:
Declare dependency as a local mock field:
new NonStrictExpectations()
{
#Cascading
private InnerDependency dependency;
{
//...
}
}
Declare dependency as an input argument for beforeMethod(), similar to what is done for normal #Test methods:
#BeforeMethod
public void beforeMethod(#Mocked #Cascading final InnerDependency dependency)
{
// ...
}
I see that JMockit 1.6+ would not like the first option and warns with WARNING: Local mock field "dependency" should be moved to the test class or converted to a parameter of the test method. Hence, to keep everyone happy, I'm ruling this option out.
But for the second option, TestNG (currently 6.8.6) throws exception when running the test saying java.lang.IllegalArgumentException: wrong number of arguments. I don't see this behavior with normal #Test cases passed with #Mocked parameters. Even playing with #Parameter and #Optional will not help (and should not have!).
So, is there any way I could make this work without declaring the unneccessary test class mock field, or am I missing something here?
Thanks
Only test methods (annotated with #Test in JUnit or TestNG) support mock parameters, so the only choice here is to declare a mock field at the test class level.
Even if not used in any test method, I think it's better than having it declared in a setup method (using #Before, #BeforeMethod, etc.). If it were to be possible, the mock would still have to apply to all tests, because of the nature of setup methods; having a mock field of the test class makes it clear what the scope of the mock is.
Dynamic partial mocking is one more technique to specify #Mocked dependencies locally. However, it has it's limitations (see comments below).

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