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How to kill a conditional boundary mutation concerning time

I'm trying to test the following class
#Component
public class StreamListener {
#Value("${kafkaMessageExpiration.maxExpirationInMilliseconds}")
private long messageExpirationTime;
public void handleMessage(Payment payment) {
logIncomingDirectDepositPayment(payment);
if (!isMessageExpired(payment.getLastPublishedDate())) {
messageProcessor.processPayment(payment);
}
}
private boolean isMessageExpired(OffsetDateTime lastPublishedDate) {
return ChronoUnit.MILLIS.between(lastPublishedDate.toInstant(), Instant.now()) > messageExpirationTime;
}
}
I'm getting a "changed conditional boundary → SURVIVED" message on the condition in isMessageExpired().
I have the following tests which test when the difference is less than messageExpirationTime and when the difference is greater than messageExpirationTime.
#BeforeEach
void init() {
ReflectionTestUtils.setField(streamListener, "messageExpirationTime", 60000);
}
#Test
void handleMessage() {
Payment payment = TestObjectBuilder.createPayment();
streamListener.handleMessage(incomingDirectDepositPayment);
verify(messageProcessor).processDirectDepositPayment(incomingDirectDepositPayment);
}
#Test
void handleMessage_expired_message() {
Payment payment = TestObjectBuilder.createPayment();
payment.setLastPublishedDate(OffsetDateTime.now(ZoneId.of("UTC")).minusMinutes(10));
streamListener.handleMessage(incomingDirectDepositPayment);
verify(messageProcessor, never()).processDirectDepositPayment(incomingDirectDepositPayment);
}
I suspect the problem is that I don't have a test where the difference is equal. Assuming that is what I'm missing, I don't know how to get the difference to be equal. Any suggestions on how I can kill this mutation?
BTW, I'm using Java 11, JUnit 5 and PITest 1.6.3

This issue is this
Instant.now()
If time is one of the inputs your code depends on you need to make that explicit so you can control it.
This is normally achieved by injecting a java.util.Clock (held as a field, injected via the constructor). Your call to Instant.now() can then be replaced with clock.instant() and the code becomes properly unit testable.

how to unit test method using "Spring Data JPA" Specifications

I was playing with org.springframework.data.jpa.domain.Specifications, it's just a basic search :
public Optional<List<Article>> rechercheArticle(String code, String libelle) {
List<Article> result = null;
if(StringUtils.isNotEmpty(code) && StringUtils.isNotEmpty(libelle)){
result = articleRepository.findAll(Specifications.where(ArticleSpecifications.egaliteCode(code)).and(ArticleSpecifications.egaliteLibelle(libelle)));
}else{
if(StringUtils.isNotEmpty(code)){
result= articleRepository.findAll(Specifications.where(ArticleSpecifications.egaliteCode(code)));
}else{
result = articleRepository.findAll(Specifications.where(ArticleSpecifications.egaliteLibelle(libelle)));
}
}
if(result.isEmpty()){
return Optional.empty();
}else{
return Optional.of(result);
}
}
And that's actually working fine but I'd like to write unit tests for this method and I can't figure out how to check specifications passed to my articleRepository.findAll()
At the moment my unit test looks like :
#Test
public void rechercheArticle_okTousCriteres() throws FacturationServiceException {
String code = "code";
String libelle = "libelle";
List<Article> articles = new ArrayList<>();
Article a1 = new Article();
articles.add(a1);
Mockito.when(articleRepository.findAll(Mockito.any(Specifications.class))).thenReturn(articles);
Optional<List<Article>> result = articleManager.rechercheArticle(code, libelle);
Assert.assertTrue(result.isPresent());
//ArgumentCaptor<Specifications> argument = ArgumentCaptor.forClass(Specifications.class);
Mockito.verify(articleRepository).findAll(Specifications.where(ArticleSpecifications.egaliteCode(code)).and(ArticleSpecifications.egaliteLibelle(libelle)));
//argument.getValue().toPredicate(root, query, builder);
}
Any idea?

I was having almost the same problems as you had, and I changed my class that contains Specifications to be an object instead of just one class with static methods. This way I can easily mock it, use dependency injection to pass it, and test which methods were called (without using PowerMockito to mock static methods).
If you wanna do like I did, I recommend you to test the correctness of specifications with integration tests, and for the rest, just if the right method was called.
For example:
public class CdrSpecs {
public Specification<Cdr> calledBetween(LocalDateTime start, LocalDateTime end) {
return (root, query, cb) -> cb.between(root.get(Cdr_.callDate), start, end);
}
}
Then you have an integration test for this method, which will test whether the method is right or not:
#RunWith(SpringRunner.class)
#DataJpaTest
#Sql("/cdr-test-data.sql")
public class CdrIntegrationTest {
#Autowired
private CdrRepository cdrRepository;
private CdrSpecs specs = new CdrSpecs();
#Test
public void findByPeriod() throws Exception {
LocalDateTime today = LocalDateTime.now();
LocalDateTime firstDayOfMonth = today.with(TemporalAdjusters.firstDayOfMonth());
LocalDateTime lastDayOfMonth = today.with(TemporalAdjusters.lastDayOfMonth());
List<Cdr> cdrList = cdrRepository.findAll(specs.calledBetween(firstDayOfMonth, lastDayOfMonth));
assertThat(cdrList).isNotEmpty().hasSize(2);
}
And now when you wanna unit test other components, you can test like this, for example:
#RunWith(JUnit4.class)
public class CdrSearchServiceTest {
#Mock
private CdrSpecs specs;
#Mock
private CdrRepository repo;
private CdrSearchService searchService;
#Before
public void setUp() throws Exception {
initMocks(this);
searchService = new CdrSearchService(repo, specs);
}
#Test
public void testSearch() throws Exception {
// some code here that interact with searchService
verify(specs).calledBetween(any(LocalDateTime.class), any(LocalDateTime.class));
// and you can verify any other method of specs that should have been called
}
And of course, inside the Service you can still use the where and and static methods of Specifications class.
I hope this can help you.

If you are writing Unit Tests then you should probably mock the call to findAll() method of articleRepository Class using a mocking framework like Mockito or PowerMock.
There is a method verify() using which you can check if the mock is invoked for the particular parameters.
For Example, if you are mocking the findAll() method of articleRepository Class and want to know if this method is called with particular arguments then you can do something like:
Mokito.verify(mymock, Mockito.times(1)).findAll(/* Provide Arguments */);
This will fail the test if mock has not been called for the arguments that you provided.

Your problem is that you are doing too many things within that one method. You should have three different methods that work on articleRepository.
Then you can use mocking as the others suggest:
setup your mocks so that you know which call on articleRepository should be made
verify that exactly the expected calls are happening
Please note: these three methods should be internal; the main point there is: you can't test this method with ONE call from the outside; as it is doing more than one thing, depending on the input that you provide. Thus you need to create at least one test method for each of the potential paths in your code. And that becomes easier (from a conceptual point of view) when you separate your code into different methods.

Mockito NotaMockException

I am facing an issue with Mockito junit testing. I am new to it and am a bit confused with the problem I am facing. Any help on this would be appreciated.
class Activity{
public void firstMethod(){
String str = secondMethod();
}
public String secondMethod(){
String str = null;
/* some Code */
return str;
}
}
Getting exception :
*org.mockito.exceptions.misusing.NotAMockException:
Argument passed to when() is not a mock!*
in the below code
class ActivityTest(){
Activity act;
#Before
public void setup(){
act = new Activity();
}
#Test
public void testFirstMethod(){
Mockito.doReturn(Mockito.anyString()).when(act).secondMethod();
act.firstMethod();
verify(act).secondMethod();
}
}
I am aware that activity is not a mock but I am not sure for a way around this as secondMethod() is a method in the same class. I need to write rule for secondMethod() as I have already done its Unit Testing. The definition of secondMethod() consists has external dependencies. Should I be mocking the external dependencies present in secondMethod() and writing rules for them rather than rule for secondMethod()?
I found this post:
Mockito Spy'ing on the object being unit tested
However separating the secondMethod() into a different class does not make sense. My method is related to this class. Creating a different class for testing does not seem right to me. Even mocking the actual class using spy() is not the most correct way as already explained in the post.
I don't think I should be creating a mock of the Activity class as that is the class I am testing. I would really appreciate help and insights into this.

As you noted, act is not a mock, and therefore you cannot record behavior on it. You could use Mockito.spy to, well, spy (or partially mock) the act object so that you only record the behavior of secondMethod and execute the actual code for firstMethod.
Note, however, that matchers can't be used in doReturn calls regardles of how you're mocking or spying your object. A return value must be a concrete object.
class ActivityTest() {
Activity act;
#Before
public void setup(){
act = Mockito.spy(new Activity()); // Here!
}
#Test
public void testFirstMethod(){
Mockito.doReturn("someString").when(act).secondMethod();
act.firstMethod();
verify(act).secondMethod();
}
}
A slightly more elegant syntax allows you to use annotations instead of explicitly calling Mockito.spy, but it's a matter of taste really:
#RunWith(MockitoJUnitRunner.class)
class ActivityTest() {
#Spy
Activity act = new Activity();
#Test
public void testFirstMethod(){
Mockito.doReturn("someString").when(act).secondMethod();
act.firstMethod();
verify(act).secondMethod();
}
}

There is no reason to mock anything in this example. Since there are no dependencies and both methods are public, you can test them directly.
public class ActivityTest() {
private Activity act = new Activity();
#Test
public void testSecondMethod(){
assertEquals("expected-value", act.secondMethod());
}
#Test
public void testFirstMethod() {
act.firstMethod();
// success if no exception occurs
}
}
Since firstMethod does not have any detectable effect on the Act instance, nor on any dependency (since there are none) you can simply call the method and be satisfied if no exception is thrown. One could also reason that such a method should not be tested at all.
I assume the example given is a simplification of a class where calling firstMethod actually does have side effects, who knows...

Here are some hints:
Mock the Activity.
Tweak the behavior of secondMethod with when / then / doReturn
Use doCallRealMethod when firstMethod is invoked.
Hope it helps.

Mock method as parameter another method

I have got a problem with testing how many times concrete methods (IFunction in the Operation instance) is invoked.
According to:
http://easymock.org/user-guide.html#mocking-annotations
http://www.ibm.com/developerworks/library/j-easymock/
How to use EasyMock expect
I wrote something as:
class Operation{
public double[] calculateSth(IFunction function, int [] t){
for(int i=0 ; i<5 ; i+=1)
function(t, new int[]{1,2,3});
return new double[]{1,2,3};
}
}
interface IFunction{
double f(int[] a, int[]b);
}
class ConcreteF implements IFunction{
double f(int[]a, int[]b){
return 5;
}
}
And my test class:
#TestSubject
Operation op;
#Mock
IFunction function;
#Before
public void setUp() throws Sth{
op=new Operation();
function = EasyMock.createMock(IFunction.class);
}
#Test
public void howManyTimes(){
EasyMock.expect(function.f(EasyMock.notNull(), EasyMock.notNull())
)
.andReturn((double)EasyMock.anyDouble()).times(3);
EasyMock.replay(function);
op.calculateSth(function, new double[]{0,0,0});
//verify
EasyMock.verify(function);
}
Result:
java.lang.NullPointerException
at org.easymock.internal.Injector.injectMocks(Injector.java:80)
at org.easymock.EasyMockSupport.injectMocks(EasyMockSupport.java:624)
at org.easymock.EasyMockRunner.withBefores(EasyMockRunner.java:50)
It's my first time using easymock and i don't know how to fix it ;/

I'll answer this question without going into the details of whether the original method does anything useful (the code doesn't even compile anyway), let alone the test method.
#TestSubject Operation op;
This line is a suspect. I realize that you are instantiating it in the #Before annotated setUp method, but it looks like the Easymock tries to inject the mocks (the ones annotated with #Mock) before it does anything (and understandably so) and blows up since the reference is null at that point.
The annotation support introduced in v3.2 is also seen as a way to eliminate the need for setUp method. But you seem to be mixing both and using it wrongly. Choose one or the other - I'd recommend you to use the annotations.
Quoting the Easymock user guide (this user guide is as good as it can ever be, so be sure read this up before using the library),
#RunWith(EasyMockRunner.class)
public class ExampleTest {
#TestSubject
private ClassUnderTest classUnderTest = new ClassUnderTest(); // 2
#Mock
private Collaborator mock; // 1
#Test
public void testRemoveNonExistingDocument() {
replay(mock);
classUnderTest.removeDocument("Does not exist");
}
}
The mock is instantiated by the runner at step 1. It is then set by
the runner, to the listener field on step 2. The setUp method can be
removed since all the initialization was done by the runner.

Unit Testing Java Code - Mocking a non-static method of a different class

public class First {
public First(){
}
public String doSecond(){
Second second = new Second();
return second.doJob();
}
}
class Second {
public String doJob(){
return "Do Something";
}
}
Here I want to test the method "doSecond()" of class "First". For the same, I want to mock the method "doJob" of class "Second".
I know that I can create a mocked instance of class "Second" using the code below.
Second sec = mock(Second.class);
when(sec.doJob()).thenReturn("Stubbed Second");
But I cannot relate this mocked instance with class "First" as of the current code.
Without refactoring the source code, is there any way by which i can achieve the requirement.
Please help.

Take a look at powermock's ability to intercept calls to new and return mocks instead
https://code.google.com/p/powermock/wiki/MockConstructor
This doesn't require changing any sourcecode.
here's the test code where we actually return a mock when First.doSecond() calls new Second()
#RunWith(PowerMockRunner.class)
#PrepareForTest(First.class)
public class TestFirst {
#Test
public void mockSecond() throws Exception{
Second mock = PowerMockito.mock(Second.class);
PowerMockito.whenNew(Second.class).withNoArguments().thenReturn(mock);
PowerMockito.when(mock.doSecond()).thenReturn("from mock");
First first = new First();
assertEquals("from mock", first.doSecond());
}
}

It's tricky to mock an instance that you create inside of a method, but it's possible.
Using PowerMock, you can accomplish this with the PowerMock.expectNew() method:
#RunWith(PowerMockRunner.class)
#PrepareForTest(First.class)
public class StackOverflowTest {
#Test
public void testFirst() throws Exception {
Second secondMock = EasyMock.createMock(Second.class);
PowerMock.expectNew(Second.class).andReturn(secondMock);
expect(secondMock.doSecond()).andReturn("Mocked!!!");
PowerMock.replay(secondMock, Second.class);
String actual = new First().doSecond();
PowerMock.verify(secondMock, Second.class);
assertThat(actual, equalTo("Mocked!!!"));
}
}
Effectively, PowerMock is proxying the creation of the new object and substituting whatever value we want when we invoke doSecond().
So, it's possible. However, this is a terrible practice to get into.
One typically wants to mock objects if they involve an outside concern, such as another layer (i.e. database, validation), or if the desired output is coming from other objects that are injected but are safe enough to consider tested.
If your method is capable of getting or retrieving data from a non-injectable source, you should not want to mock that out.
Considering that your method is simple and straightforward, you should really not need to do any mocks here at all. But if you felt that you were forced to, you could do one of a few things:
Create a factory for the creation of Second, and mock the results of the returning factory object with Mockito.
Pass in an instance of Second to that method, and use Mockito as the mock instance.
Declare it as a field (i.e. injected dependency), and use Mockito.

For completeness, here is how the test can be written with the JMockit mocking API, without any refactoring of the original code under test:
public class ExampleTest
{
#Test
public void firstShouldCallSecond(#Mocked final Second secondMock) {
new NonStrictExpectations() {{
secondMock.doJob(); result = "Mocked!!!";
}};
String actual = new First().doSecond();
assertEquals("Mocked!!!", actual);
}
}