diff --git a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseServiceTest.java b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseServiceTest.java
index 4624d55445b4a0c78cd64d51796a1b61d02ae23f..7d54a6cc2869ee3e00af9abb67933de0ca71a9c6 100644
--- a/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseServiceTest.java
+++ b/application/module-exercise/src/test/java/org/fuseri/moduleexercise/exercise/ExerciseServiceTest.java
@@ -2,9 +2,6 @@ package org.fuseri.moduleexercise.exercise;
 
 import jakarta.persistence.EntityNotFoundException;
 import org.fuseri.model.dto.exercise.ExerciseCreateDto;
-//import org.fuseri.modulelanguageschool.common.ResourceNotFoundException;
-
-import org.fuseri.model.dto.exercise.ExerciseDto;
 import org.fuseri.moduleexercise.question.Question;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.BeforeEach;
@@ -27,13 +24,13 @@ import static org.mockito.Mockito.when;
 
 
 @SpringBootTest
-public class ExerciseServiceTest {
+class ExerciseServiceTest {
 
     @MockBean
-    ExerciseRepository repository;
+    ExerciseRepository exerciseRepository;
 
     @Autowired
-    ExerciseService service;
+    ExerciseService exerciseService;
 
     Exercise exercise;
     ExerciseCreateDto exercise2;
@@ -41,35 +38,34 @@ public class ExerciseServiceTest {
 
     @BeforeEach
     void setup() {
-        exercise = new Exercise("idioms", "exercise on basic idioms",2,1L,new HashSet<Question>());
+        exercise = new Exercise("idioms", "exercise on basic idioms", 2, 1L, new HashSet<>());
         exercise2 = new ExerciseCreateDto("idioms1", "exercise on intermediate idioms", 2, 0);
         exercise3 = new ExerciseCreateDto("idioms2", "exercise on basic idioms", 1, 0L);
     }
 
-
     @Test
     void create() {
-        when(repository.save(exercise)).thenReturn(exercise);
-        Exercise result = service.create(exercise);
+        when(exerciseRepository.save(exercise)).thenReturn(exercise);
+        Exercise result = exerciseService.create(exercise);
         Assertions.assertEquals(exercise, result);
-        verify(repository).save(exercise);
+        verify(exerciseRepository).save(exercise);
     }
 
     @Test
     void notFound() {
-        when(repository.findById(anyLong())).thenReturn(Optional.empty());
+        when(exerciseRepository.findById(anyLong())).thenReturn(Optional.empty());
 
-        Assertions.assertThrows(EntityNotFoundException.class, () -> service.find(anyLong()));
+        Assertions.assertThrows(EntityNotFoundException.class, () -> exerciseService.find(anyLong()));
     }
 
     @Test
     void find() {
-        when(repository.findById(anyLong())).thenReturn(Optional.of(exercise));
+        when(exerciseRepository.findById(anyLong())).thenReturn(Optional.of(exercise));
 
-        Exercise result = service.find(anyLong());
+        Exercise result = exerciseService.find(anyLong());
 
         Assertions.assertEquals(exercise, result);
-        verify(repository).findById(anyLong());
+        verify(exerciseRepository).findById(anyLong());
     }
 
     @Test
@@ -77,24 +73,24 @@ public class ExerciseServiceTest {
         Pageable pageable = PageRequest.of(0, 10);
         Page<Exercise> page = new PageImpl<>(Collections.emptyList(), pageable, 0);
 
-        when(repository.findAll(pageable)).thenReturn(page);
-        Page<Exercise> result = service.findAll(0);
+        when(exerciseRepository.findAll(pageable)).thenReturn(page);
+        Page<Exercise> result = exerciseService.findAll(0);
 
         Assertions.assertEquals(page, result);
-        verify(repository).findAll(pageable);
+        verify(exerciseRepository).findAll(pageable);
     }
 
     @Test
-    void findPerDiffPerCourse() {
+    void findByCourseIdAndDifficulty() {
         PageRequest pageable = PageRequest.of(0, 10);
         Page<Exercise> page = new PageImpl<>(Collections.emptyList(), pageable, 0);
 
-        when(repository.filterPerDifficultyPerCourse(pageable,1L,2)).thenReturn(page);
+        when(exerciseRepository.findByCourseIdAndDifficulty(1L, 2, pageable)).thenReturn(page);
 
-        Page<Exercise> result = service.findPerDifficultyPerCourse(0,1L,2);
+        Page<Exercise> result = exerciseService.findByCourseIdAndDifficulty(1L, 2, 0);
 
         Assertions.assertEquals(page, result);
-        verify(repository).filterPerDifficultyPerCourse(pageable,1L,2);
+        verify(exerciseRepository).findByCourseIdAndDifficulty(1L, 2, pageable);
     }
 
 
@@ -103,13 +99,13 @@ public class ExerciseServiceTest {
         PageRequest pageable = PageRequest.of(0, 10);
         Page<Question> page = new PageImpl<>(Collections.emptyList(), pageable, 0);
 
-        when(repository.getQuestions(pageable,1L)).thenReturn(page);
-        when(repository.existsById(1L)).thenReturn(true);
+        when(exerciseRepository.getQuestions(pageable, 1L)).thenReturn(page);
+        when(exerciseRepository.existsById(1L)).thenReturn(true);
 
 
-        Page<Question> result = service.getQuestions(1L,0);
+        Page<Question> result = exerciseService.getQuestions(1L, 0);
 
         Assertions.assertEquals(page, result);
-        verify(repository).getQuestions(pageable,1L);
+        verify(exerciseRepository).getQuestions(pageable, 1L);
     }
 }