diff --git a/pom.xml b/pom.xml
index f492dbd..121c81e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -35,6 +35,25 @@
 				<groupId>org.springframework.boot</groupId>
 				<artifactId>spring-boot-maven-plugin</artifactId>
 			</plugin>
+			<plugin>
+				<groupId>org.jacoco</groupId>
+				<artifactId>jacoco-maven-plugin</artifactId>
+				<version>0.8.10</version>
+				<executions>
+					<execution>
+						<goals>
+							<goal>prepare-agent</goal>
+						</goals>
+					</execution>
+					<execution>
+						<id>report</id>
+						<phase>test</phase>
+						<goals>
+							<goal>report</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
 		</plugins>
 	</build>
 
diff --git a/src/test/java/com/bezkoder/spring/restapi/controller/TutorialControllerTest.java b/src/test/java/com/bezkoder/spring/restapi/controller/TutorialControllerTest.java
new file mode 100644
index 0000000..3c621b7
--- /dev/null
+++ b/src/test/java/com/bezkoder/spring/restapi/controller/TutorialControllerTest.java
@@ -0,0 +1,200 @@
+// java
+package com.bezkoder.spring.restapi.controller;
+
+import static org.mockito.Mockito.doNothing;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.delete;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+import java.util.Collections;
+import java.util.List;
+
+import com.bezkoder.spring.restapi.model.Tutorial;
+import com.bezkoder.spring.restapi.service.TutorialService;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+@ExtendWith(MockitoExtension.class)
+class TutorialControllerTest {
+
+    private MockMvc mockMvc;
+    private ObjectMapper objectMapper = new ObjectMapper();
+
+    @Mock
+    private TutorialService tutorialService;
+
+    @InjectMocks
+    private TutorialController tutorialController;
+
+    @BeforeEach
+    void setup() {
+        mockMvc = MockMvcBuilders.standaloneSetup(tutorialController).build();
+    }
+
+    @Test
+    void getAllTutorials_returnsList() throws Exception {
+        Tutorial t = new Tutorial();
+        t.setId(1L);
+        t.setTitle("Title");
+        t.setDescription("Desc");
+        t.setPublished(true);
+
+        when(tutorialService.findAll()).thenReturn(List.of(t));
+
+        mockMvc.perform(get("/api/tutorials"))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$[0].id").value(1))
+                .andExpect(jsonPath("$[0].title").value("Title"));
+    }
+
+    @Test
+    void getAllTutorials_noContent() throws Exception {
+        when(tutorialService.findAll()).thenReturn(Collections.emptyList());
+
+        mockMvc.perform(get("/api/tutorials"))
+                .andExpect(status().isNoContent());
+    }
+
+    @Test
+    void getTutorialById_found() throws Exception {
+        Tutorial t = new Tutorial();
+        t.setId(1L);
+        t.setTitle("Found");
+        when(tutorialService.findById(1L)).thenReturn(t);
+
+        mockMvc.perform(get("/api/tutorials/1"))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.title").value("Found"));
+    }
+
+    @Test
+    void getTutorialById_notFound() throws Exception {
+        when(tutorialService.findById(1L)).thenReturn(null);
+
+        mockMvc.perform(get("/api/tutorials/1"))
+                .andExpect(status().isNotFound());
+    }
+
+    @Test
+    void createTutorial_success() throws Exception {
+        Tutorial input = new Tutorial();
+        input.setTitle("New");
+        input.setDescription("D");
+        input.setPublished(false);
+
+        Tutorial saved = new Tutorial();
+        saved.setId(10L);
+        saved.setTitle("New");
+        saved.setDescription("D");
+        saved.setPublished(false);
+
+        when(tutorialService.save(org.mockito.ArgumentMatchers.any(Tutorial.class))).thenReturn(saved);
+
+        mockMvc.perform(post("/api/tutorials")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content(objectMapper.writeValueAsString(input)))
+                .andExpect(status().isCreated())
+                .andExpect(jsonPath("$.id").value(10))
+                .andExpect(jsonPath("$.title").value("New"));
+    }
+
+    @Test
+    void updateTutorial_found() throws Exception {
+        Tutorial existing = new Tutorial();
+        existing.setId(1L);
+        existing.setTitle("Old");
+        existing.setDescription("OldD");
+        existing.setPublished(false);
+
+        Tutorial update = new Tutorial();
+        update.setTitle("Updated");
+        update.setDescription("NewD");
+        update.setPublished(true);
+
+        Tutorial saved = new Tutorial();
+        saved.setId(1L);
+        saved.setTitle("Updated");
+        saved.setDescription("NewD");
+        saved.setPublished(true);
+
+        when(tutorialService.findById(1L)).thenReturn(existing);
+        when(tutorialService.save(org.mockito.ArgumentMatchers.any(Tutorial.class))).thenReturn(saved);
+
+        mockMvc.perform(put("/api/tutorials/1")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content(objectMapper.writeValueAsString(update)))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.title").value("Updated"))
+                .andExpect(jsonPath("$.published").value(true));
+    }
+
+    @Test
+    void updateTutorial_notFound() throws Exception {
+        when(tutorialService.findById(1L)).thenReturn(null);
+
+        Tutorial update = new Tutorial();
+        update.setTitle("X");
+
+        mockMvc.perform(put("/api/tutorials/1")
+                        .contentType(MediaType.APPLICATION_JSON)
+                        .content(objectMapper.writeValueAsString(update)))
+                .andExpect(status().isNotFound());
+    }
+
+    @Test
+    void deleteTutorial_success() throws Exception {
+        doNothing().when(tutorialService).deleteById(1L);
+
+        mockMvc.perform(delete("/api/tutorials/1"))
+                .andExpect(status().isNoContent());
+
+        verify(tutorialService).deleteById(1L);
+    }
+
+    @Test
+    void deleteAllTutorials_success() throws Exception {
+        doNothing().when(tutorialService).deleteAll();
+
+        mockMvc.perform(delete("/api/tutorials"))
+                .andExpect(status().isNoContent());
+
+        verify(tutorialService).deleteAll();
+    }
+
+    @Test
+    void findByPublished_returnsList() throws Exception {
+        Tutorial t = new Tutorial();
+        t.setId(2L);
+        t.setTitle("Pub");
+        t.setPublished(true);
+
+        when(tutorialService.findByPublished(true)).thenReturn(List.of(t));
+
+        mockMvc.perform(get("/api/tutorials/published"))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$[0].id").value(2))
+                .andExpect(jsonPath("$[0].published").value(true));
+    }
+
+    @Test
+    void findByPublished_noContent() throws Exception {
+        when(tutorialService.findByPublished(true)).thenReturn(Collections.emptyList());
+
+        mockMvc.perform(get("/api/tutorials/published"))
+                .andExpect(status().isNoContent());
+    }
+}
diff --git a/src/test/java/com/bezkoder/spring/restapi/service/TutorialServiceTest.java b/src/test/java/com/bezkoder/spring/restapi/service/TutorialServiceTest.java
new file mode 100644
index 0000000..63e8e09
--- /dev/null
+++ b/src/test/java/com/bezkoder/spring/restapi/service/TutorialServiceTest.java
@@ -0,0 +1,93 @@
+package com.bezkoder.spring.restapi.service;
+
+import com.bezkoder.spring.restapi.model.Tutorial;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class TutorialServiceTest {
+
+    private TutorialService service;
+
+    @BeforeEach
+    void setUp() {
+        service = new TutorialService();
+        // reset static state
+        TutorialService.tutorials.clear();
+        TutorialService.id = 0;
+    }
+
+    @Test
+    void testSaveCreateAndFindAll() {
+        Tutorial t1 = new Tutorial();
+        t1.setTitle("Java");
+        t1.setDescription("desc");
+        t1.setPublished(true);
+
+        Tutorial saved = service.save(t1);
+        assertEquals(1L, saved.getId());
+        List<Tutorial> all = service.findAll();
+        assertEquals(1, all.size());
+        assertSame(saved, all.get(0));
+    }
+
+    @Test
+    void testSaveUpdate() {
+        Tutorial t = new Tutorial();
+        t.setTitle("Original");
+        t.setDescription("d");
+        t.setPublished(false);
+        Tutorial saved = service.save(t);
+
+        saved.setTitle("Updated");
+        saved.setPublished(true);
+        Tutorial updated = service.save(saved);
+
+        assertEquals(saved.getId(), updated.getId());
+        Tutorial found = service.findById(saved.getId());
+        assertNotNull(found);
+        assertEquals("Updated", found.getTitle());
+        assertTrue(found.isPublished());
+    }
+
+    @Test
+    void testFindByIdNotFound() {
+        assertNull(service.findById(999L));
+    }
+
+    @Test
+    void testFindByTitleContaining() {
+        Tutorial t1 = new Tutorial(); t1.setTitle("Spring Boot Guide"); service.save(t1);
+        Tutorial t2 = new Tutorial(); t2.setTitle("Other"); service.save(t2);
+
+        List<Tutorial> results = service.findByTitleContaining("Boot");
+        assertEquals(1, results.size());
+        assertTrue(results.get(0).getTitle().contains("Boot"));
+    }
+
+    @Test
+    void testFindByPublished() {
+        Tutorial t1 = new Tutorial(); t1.setTitle("Pub"); t1.setPublished(true); service.save(t1);
+        Tutorial t2 = new Tutorial(); t2.setTitle("Unpub"); t2.setPublished(false); service.save(t2);
+
+        List<Tutorial> published = service.findByPublished(true);
+        assertEquals(1, published.size());
+        assertTrue(published.get(0).isPublished());
+    }
+
+    @Test
+    void testDeleteByIdAndDeleteAll() {
+        Tutorial t1 = new Tutorial(); t1.setTitle("A"); service.save(t1);
+        Tutorial t2 = new Tutorial(); t2.setTitle("B"); service.save(t2);
+
+        assertEquals(2, service.findAll().size());
+        service.deleteById(1L);
+        assertEquals(1, service.findAll().size());
+
+        service.deleteAll();
+        assertEquals(0, service.findAll().size());
+    }
+}