Mockito fails for Spring data JPA Page interface - spring-data-jpa

Question

#SpringBootTest
public class TestClass {
#Mock
private Page<Customer> pagedResult;
#Mock
private Pageable paging = PageRequest.of(0, 1);
#Mock
private CustomerRepository cutomerRepository;
#InjectMocks
private CustomerServiceImpl service;
#Test
void testss() {
Set<Integer> set = new HashSet<>();
set.add(1);
Pageable paging1 = PageRequest.of(0, 1);
Page<Customer> pa = new PageImpl<>(Arrays.asList(customer));
when(cutomerRepository.findByIdIn(set, paging1)).thenReturn(pa);
when(service.test(set)).thenReturn(Arrays.asList(customer));
assertEquals(customer.getName(), service.test(set).get(0).getgetName());
}
}
Implementation class
public class CustomerServiceImpl {
private CustomerRepository customerRepository ;
public CustomerServiceImpl(CustomerRepository customerRepository ) {
super();
this.customerRepository = customerRepository ;
}
#Override
public List<Customer> test(Set<Integer> ids) {
Pageable paging = PageRequest.of(0, 1);
Page<Customer> pagedResult = customerRepository.findByIdIn(ids, paging);
return pagedResult.toList();
}
}
I am trying to write the Junit test case for my pagination code using mockito but it fails as it is expecting the return type for method as Page.but I am returning List of Customers.When I return Page from method it works fine but if I return List is fails with below mentioned error
I am getting below error
org.mockito.exceptions.misusing.WrongTypeOfReturnValue:
ArrayList cannot be returned by findByIdIn()
findByIdIn() should return Page
If you're unsure why you're getting above error read on.
Due to the nature of the syntax above problem might occur because:
This exception might occur in wrongly written multi-threaded tests.
Please refer to Mockito FAQ on limitations of concurrency testing.
A spy is stubbed using when(spy.foo()).then() syntax. It is safer to stub spies -
with doReturn|Throw() family of methods. More in javadocs for Mockito.spy() method.

Answer 1

I think something is messed with your code.
In Your code you have doctorRepository.findByIdIn Method bt in your test class it is cutomerRepository.findByIdIn.
I have added the below code as a reference with respect to your CustomerServiceImpl.
You can try the same way to execute your test.
SpringBootTest
public class TestClass {
#Mock
private Pageable paging;
#Mock
private CustomerRepository cutomerRepository;
#Mock
private DoctorRepository doctorRepository;
#InjectMocks
private CustomerServiceImpl service;
#Test
void testss() {
Doctor doctor = new Doctor();
doctor.setName("test name");
Set<Integer> set = new HashSet<>();
set.add(1);
PageImpl<Doctor> page = new PageImpl<>(Arrays.asList(doctor));
when(doctorRepository.findByIdIn(Mockito.any(), Mockito.any())).thenReturn(page);
List<Doctor> doctors= service.test(set);
assertEquals(doctor.getName(), doctors.get(0).getgetName());
}
}