Handling the removal of Mockito's Whitebox in version 2.x involves several strategies to adapt your testing code. Here are some detailed approaches:
Understanding the Removal
Mockito 2.x no longer includes the Whitebox class, which was used for reflection to set internal states of objects. This removal was intentional to discourage bad testing practices that rely heavily on internal state manipulation rather than using public APIs for testing[9][11].Alternatives to Whitebox
1. PowerMock's Whitebox**
You can use PowerMock's Whitebox as an alternative. However, this introduces an additional dependency and might not work seamlessly with Mockito 2.x due to potential issues like `FieldNotFoundException`[1][10]. Ensure you use compatible versions of Mockito and PowerMock.2. ReflectionTestUtils (Spring Test Library)**
If you are using Spring, you can leverage `ReflectionTestUtils` from the Spring Test library to set fields. This is a straightforward alternative that does not require additional dependencies beyond Spring[7].3. Apache Commons Lang**
Another option is to use Apache Commons Lang's `FieldUtils` for reflection. This library provides a robust way to access and modify fields without relying on Mockito or PowerMock[7].4. Fest-Reflect**
Fest-Reflect offers a fluent API for reflection, which can be used to manipulate object states. It's particularly useful if you prefer a more readable and fluent syntax[7].5. Refactor Your Tests**
The most recommended approach is to refactor your tests to avoid needing Whitebox altogether. This involves designing your code to be more testable by using public APIs or dependency injection, which is considered a better testing practice[9].Example of Using ReflectionTestUtils
If you are using Spring, here's how you might use `ReflectionTestUtils` to set a field:
java
import org.springframework.util.ReflectionTestUtils;
// Assuming you have an object named 'eventHandler'
// and you want to set 'registrationService' field to 'registrationServiceMock'
Object registrationServiceMock = mock(RegistrationService.class);
ReflectionTestUtils.setField(eventHandler, "registrationService", registrationServiceMock);
Example of Using Apache Commons Lang
Here's how you might use `FieldUtils` from Apache Commons Lang:
java
import org.apache.commons.lang3.reflect.FieldUtils;
// Assuming you have an object named 'eventHandler'
// and you want to set 'registrationService' field to 'registrationServiceMock'
Object registrationServiceMock = mock(RegistrationService.class);
try {
FieldUtils.writeField(eventHandler, "registrationService", registrationServiceMock, true);
} catch (IllegalAccessException e) {
// Handle exception
}
In summary, while PowerMock's Whitebox can be used as a temporary solution, it's advisable to move towards more sustainable testing practices by refactoring your code or using libraries like Spring Test or Apache Commons Lang for reflection needs.
Citations:[1] https://proandroiddev.com/mockito-2-x-over-powermock-migration-tips-and-tricks-top-ten-118c52abd1d8
[2] https://docs.openrewrite.org/recipes/java/testing/mockito/replacepowermockito
[3] https://help.sap.com/docs/SAP_COMMERCE/a74589c3a81a4a95bf51d87258c0ab15/277f145325a4409b975f6e2af91b7401.html
[4] https://issues.apache.org/jira/browse/HADOOP-14188
[5] https://github.com/powermock/powermock/wiki/Bypass-Encapsulation
[6] https://support.intershop.com/kb/go.php/a/ENFDEVDOC/pages/1827636063/Guide+-+7.10+Migration+Mockito+1+to+Mockito+2
[7] https://stackoverflow.com/questions/40280918/what-do-i-use-instead-of-whitebox-in-mockito-2-2-to-set-fields
[8] https://www.calsoftinc.com/blogs/unit-testing-mockito-powermockito.html
[9] https://proandroiddev.com/mockito-2-x-migration-session-recording-droidcon-uk-2018-ba70619f3811
[10] https://dzone.com/articles/mockito-2x-over-powermock-migration-top-10-tips-and-tricks
[11] https://github.com/mockito/mockito/issues/489