Spring Boot / JUnit 5 / Mockito - mocking dependencies in Test classes

I am trying to write JUnit 5 tests for a Spring Boot API but running into problem with dependency injection in the Test class. I wish to test endpoints in the ProfileController, which has 3 dependencies: ProfileService, ProfileModelAssembler (to add REST-centric decorations to json response, e.g. "links") and ModelMapper. In my Test class, I have the following 3 annotated as shown:

@InjectMocks
ProfileController profileController;

@Mock
ProfileService profileService;

@Mock
ProfileModelAssembler profileModelAssembler;

@Mock
ModelMapper modelMapper;

When I try to run a test, it errors out instantiating the ProfileController due to unsatisfied dependency for the ProfileService ("No qualifying bean of type x.ProfileService available").

In my ProfileController, I have tried to @Autowire those fields directly (not recommended, I know):

@Autowired
private ProfileService profileService;
@Autowired
private ProfileModelAssembler profileModelAssembler;
@Autowired
private ModelMapper modelMapper;

as well as via constructor injection:

@Autowired
public ProfileController(ProfileService profileService, ProfileModelAssembler profileModelAssembler, ModelMapper modelMapper) {
    this.profileService = profileService;
    this.profileModelAssembler = profileModelAssembler;
    this.modelMapper = modelMapper;
}

Error is the same either way. Tutorials I have found for JUnit and Mockito are absolutely all over the place in approach, doing things radically different from one another. I know there are always multiple solutions to a problem, but I've been surprised at how little adherence to any sort of "preferred" practice there is. Any recommendations to eliminate this error or resources to which I could turn to learn JUnit/Mockito in a "simple" way for my relatively simple needs?

@Mock and @InjectMocks annotations have nothing to do with Spring so it doesn't matter how you autowire the dependencies in the ProfileController class. From the error you got it looks like you are running the test with @SpringBootTest where the application context is started so you would need to use the @MockBean annotations on ProfileService and others in order for them to be injected into the application context.

Alternatively, you can have a basic unit test without starting the whole application context where @Mock and @InjectMocks annotations would work as you expect. Just make sure to properly initialize the mocks. The easiest way would be to annotate the test class with @ExtendWith(MockitoExtension.class)