remove follow

src/main/java/io/spring/api/ProfileApi.java

@@ -9,6 +9,7 @@ import io.spring.core.user.UserRepository;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.core.annotation.AuthenticationPrincipal;
+import org.springframework.web.bind.annotation.DeleteMapping;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
@@ -16,6 +17,7 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
 import java.util.HashMap;
+import java.util.Optional;
 
 @RestController
 @RequestMapping(path = "profiles/{username}")
@@ -47,6 +49,22 @@ public class ProfileApi {
         }).orElseThrow(ResourceNotFoundException::new);
     }
 
+    @DeleteMapping(path = "follow")
+    public ResponseEntity unfollow(@PathVariable("username") String username,
+                                   @AuthenticationPrincipal User user) {
+        Optional<User> userOptional = userRepository.findByUsername(username);
+        if (userOptional.isPresent()) {
+            User target = userOptional.get();
+            return userRepository.findRelation(user.getId(), target.getId())
+                .map(relation -> {
+                    userRepository.removeRelation(relation);
+                    return profileResponse(profileQueryService.findByUsername(username, user).get());
+                }).orElseThrow(ResourceNotFoundException::new);
+        } else {
+            throw new ResourceNotFoundException();
+        }
+    }
+
     private ResponseEntity profileResponse(ProfileData profile) {
         return ResponseEntity.ok(new HashMap<String, Object>() {{
             put("profile", profile);

src/main/java/io/spring/core/user/UserRepository.java

@@ -17,4 +17,6 @@ public interface UserRepository {
     void saveRelation(FollowRelation followRelation);
 
     Optional<FollowRelation> findRelation(String userId, String targetId);
+
+    void removeRelation(FollowRelation followRelation);
 }

src/main/java/io/spring/infrastructure/user/MyBatisUserRepository.java

@@ -43,11 +43,18 @@ public class MyBatisUserRepository implements UserRepository {
 
     @Override
     public void saveRelation(FollowRelation followRelation) {
-        userMapper.saveRelation(followRelation);
+        if (!findRelation(followRelation.getUserId(), followRelation.getTargetId()).isPresent()) {
+            userMapper.saveRelation(followRelation);
+        }
     }
 
     @Override
     public Optional<FollowRelation> findRelation(String userId, String targetId) {
         return Optional.ofNullable(userMapper.findRelation(userId, targetId));
     }
+
+    @Override
+    public void removeRelation(FollowRelation followRelation) {
+        userMapper.deleteRelation(followRelation);
+    }
 }

src/main/java/io/spring/infrastructure/user/UserMapper.java

@@ -21,4 +21,6 @@ public interface UserMapper {
     FollowRelation findRelation(@Param("userId") String userId, @Param("targetId") String targetId);
 
     void saveRelation(@Param("followRelation") FollowRelation followRelation);
+
+    void deleteRelation(@Param("followRelation") FollowRelation followRelation);
 }

src/main/resources/mapper/UserMapper.xml

@@ -25,6 +25,9 @@
           </set>
         where id = #{user.id}
     </update>
+    <delete id="deleteRelation">
+        delete from follows where user_id = #{followRelation.userId} and follow_id = #{followRelation.targetId}
+    </delete>
     <select id="findByUsername" resultMap="user">
         select * from users where username = #{username}
     </select>

src/test/java/io/spring/api/ProfileApiTest.java

@@ -3,7 +3,9 @@ package io.spring.api;
 import io.restassured.RestAssured;
 import io.spring.application.profile.ProfileData;
 import io.spring.application.profile.ProfileQueryService;
+import io.spring.application.profile.UserRelationshipQueryService;
 import io.spring.core.article.Article;
+import io.spring.core.user.FollowRelation;
 import io.spring.core.user.User;
 import io.spring.core.user.UserRepository;
 import org.junit.Before;
@@ -18,7 +20,9 @@ import java.util.Optional;
 
 import static io.restassured.RestAssured.given;
 import static org.hamcrest.core.IsEqual.equalTo;
+import static org.mockito.Matchers.any;
 import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 @RunWith(SpringRunner.class)
@@ -40,6 +44,7 @@ public class ProfileApiTest extends TestWithCurrentUser {
         userFixture();
         anotherUser = new User("username@test.com", "username", "123", "", "");
         profileData = new ProfileData(anotherUser.getId(), anotherUser.getUsername(), anotherUser.getBio(), anotherUser.getImage(), false);
+        when(userRepository.findByUsername(eq(anotherUser.getUsername()))).thenReturn(Optional.of(anotherUser));
     }
 
     @Test
@@ -56,7 +61,6 @@ public class ProfileApiTest extends TestWithCurrentUser {
 
     @Test
     public void should_follow_user_success() throws Exception {
-        when(userRepository.findByUsername(eq(anotherUser.getUsername()))).thenReturn(Optional.of(anotherUser));
         when(profileQueryService.findByUsername(eq(profileData.getUsername()), eq(user))).thenReturn(Optional.of(profileData));
         given()
             .header("Authorization", "Token " + token)
@@ -65,6 +69,23 @@ public class ProfileApiTest extends TestWithCurrentUser {
             .prettyPeek()
             .then()
             .statusCode(200);
+        verify(userRepository).saveRelation(new FollowRelation(user.getId(), anotherUser.getId()));
+    }
 
+    @Test
+    public void should_unfollow_user_success() throws Exception {
+        FollowRelation followRelation = new FollowRelation(user.getId(), anotherUser.getId());
+        when(userRepository.findRelation(eq(user.getId()), eq(anotherUser.getId()))).thenReturn(Optional.of(followRelation));
+        when(profileQueryService.findByUsername(eq(profileData.getUsername()), eq(user))).thenReturn(Optional.of(profileData));
+
+        given()
+            .header("Authorization", "Token " + token)
+            .when()
+            .delete("/profiles/{username}/follow", anotherUser.getUsername())
+            .prettyPeek()
+            .then()
+            .statusCode(200);
+
+        verify(userRepository).removeRelation(eq(followRelation));
     }
 }

src/test/java/io/spring/infrastructure/user/MyBatisUserRepositoryTest.java

@@ -65,4 +65,16 @@ public class MyBatisUserRepositoryTest {
         userRepository.saveRelation(followRelation);
         assertThat(userRepository.findRelation(user.getId(), other.getId()).isPresent(), is(true));
     }
+
+    @Test
+    public void should_unfollow_user_success() throws Exception {
+        User other = new User("other@example.com", "other", "123", "", "");
+        userRepository.save(other);
+
+        FollowRelation followRelation = new FollowRelation(user.getId(), other.getId());
+        userRepository.saveRelation(followRelation);
+
+        userRepository.removeRelation(followRelation);
+        assertThat(userRepository.findRelation(user.getId(), other.getId()).isPresent(), is(false));
+    }
 }