Added: controller for handling overview information and respective se…

…rvice. Pull out into abstraction mutual error handling, from services, and then in the controllers as well. Created necessary tests, and fixed some broken ones.

src/main/java/com/minitwitter/controller/ExceptionHandlingController.java

@@ -0,0 +1,22 @@
+package com.minitwitter.controller;
+
+import com.minitwitter.domain.dto.ErrorMessage;
+import com.minitwitter.service.ExceptionHandlingService;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestController;
+
+import static org.springframework.http.HttpStatus.BAD_REQUEST;
+
+@RestController
+@Slf4j
+public abstract class ExceptionHandlingController {
+
+  @ExceptionHandler
+  @ResponseStatus(BAD_REQUEST)
+  public ErrorMessage handleUnknownUsernameException(ExceptionHandlingService.UnknownUsernameException e) {
+    log.warn("", e);
+    return new ErrorMessage(String.format("Unknown user '%s'", e.getUsername()));
+  }
+}

src/main/java/com/minitwitter/controller/OverviewController.java

@@ -0,0 +1,27 @@
+package com.minitwitter.controller;
+
+import com.minitwitter.domain.dto.UserOverviewDTO;
+import com.minitwitter.service.OverviewService;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("overview")
+@Slf4j
+public class OverviewController extends ExceptionHandlingController{
+
+  private OverviewService overviewService;
+
+  public OverviewController(OverviewService overviewService) {
+    this.overviewService = overviewService;
+  }
+
+  @GetMapping(value = "{username}")
+  public UserOverviewDTO followers(@PathVariable String username) {
+    return overviewService.getUsersFollowers(username);
+  }
+
+}

src/main/java/com/minitwitter/controller/TweetController.java

@@ -1,10 +1,9 @@
 package com.minitwitter.controller;
 
 import com.minitwitter.domain.dto.ErrorMessage;
+import com.minitwitter.domain.dto.TweetDTO;
 import com.minitwitter.service.TweetService;
 import com.minitwitter.service.TweetService.InvalidTweetException;
-import com.minitwitter.service.TweetService.UnknownUsernameException;
-import com.minitwitter.domain.dto.TweetDTO;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.GetMapping;
@@ -24,7 +23,7 @@
 @RestController
 @RequestMapping("tweets")
 @Slf4j
-public class TweetController {
+public class TweetController extends ExceptionHandlingController {
 
   private TweetService tweetService;
 
@@ -48,13 +47,6 @@ public Collection<TweetDTO> tweetsFromUser(@PathVariable String username) {
     return tweetService.tweetsFromUser(username);
   }
 
-  @ExceptionHandler
-  @ResponseStatus(BAD_REQUEST)
-  public ErrorMessage handleUnknownUsernameException(UnknownUsernameException e) {
-    log.warn("", e);
-    return new ErrorMessage(String.format("Unknown user '%s'", e.getUsername()));
-  }
-
   @ExceptionHandler
   @ResponseStatus(BAD_REQUEST)
   public ErrorMessage handleInvalidTweetException(InvalidTweetException e) {

src/main/java/com/minitwitter/domain/dto/UserOverviewDTO.java

@@ -0,0 +1,16 @@
+package com.minitwitter.domain.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import static lombok.AccessLevel.PRIVATE;
+
+@Getter
+@AllArgsConstructor
+@NoArgsConstructor(access = PRIVATE)
+public class UserOverviewDTO {
+  private int tweets;
+  private int followers;
+  private int following;
+}

src/main/java/com/minitwitter/repository/TweetRepository.java

@@ -10,4 +10,6 @@
 @Repository
 public interface TweetRepository extends JpaRepository<Tweet, Long> {
   List<Tweet> findAllByAuthor(User author);
+
+  int countByAuthorUsername(String username);
 }

src/main/java/com/minitwitter/service/ExceptionHandlingService.java

@@ -0,0 +1,34 @@
+package com.minitwitter.service;
+
+import com.minitwitter.domain.User;
+import com.minitwitter.repository.UserRepository;
+import lombok.Getter;
+import org.springframework.stereotype.Service;
+
+@Service
+public abstract class ExceptionHandlingService {
+
+  private UserRepository userRepository;
+
+  public ExceptionHandlingService(UserRepository userRepository) {
+    this.userRepository = userRepository;
+  }
+
+  protected User getUser(String username) {
+    User user = userRepository.findOneByUsername(username);
+    if (user != null) {
+      return user;
+    }
+    throw new UnknownUsernameException(username);
+  }
+
+  public static class UnknownUsernameException extends RuntimeException {
+    @Getter
+    private String username;
+
+    private UnknownUsernameException(String username) {
+      super(username);
+      this.username = username;
+    }
+  }
+}

src/main/java/com/minitwitter/service/OverviewService.java

@@ -0,0 +1,32 @@
+package com.minitwitter.service;
+
+import com.minitwitter.domain.User;
+import com.minitwitter.domain.dto.UserOverviewDTO;
+import com.minitwitter.repository.TweetRepository;
+import com.minitwitter.repository.UserRepository;
+import org.springframework.stereotype.Service;
+
+import javax.transaction.Transactional;
+
+@Service
+public class OverviewService extends ExceptionHandlingService {
+
+  private TweetRepository tweetRepository;
+
+  public OverviewService(TweetRepository tweetRepository, UserRepository userRepository) {
+    super(userRepository);
+    this.tweetRepository = tweetRepository;
+  }
+
+  @Transactional
+  public UserOverviewDTO getUsersFollowers(String username) {
+    int tweets = this.tweetRepository.countByAuthorUsername(username);
+
+    User user = this.getUser(username);
+    int followers = user.getFollowers().size();
+    int following = user.getFollowing().size();
+
+    return new UserOverviewDTO(tweets, followers, following);
+  }
+
+}

src/main/java/com/minitwitter/service/TweetService.java

@@ -15,14 +15,13 @@
 import static java.util.stream.Collectors.toList;
 
 @Service
-public class TweetService {
+public class TweetService extends ExceptionHandlingService {
 
   private TweetRepository tweetRepository;
-  private UserRepository userRepository;
 
   public TweetService(TweetRepository tweetRepository, UserRepository userRepository) {
+    super(userRepository);
     this.tweetRepository = tweetRepository;
-    this.userRepository = userRepository;
   }
 
   public Collection<TweetDTO> followingUsersTweets(Principal principal) {
@@ -53,24 +52,6 @@ private List<TweetDTO> tweetsFromUser(User user) {
     return tweetRepository.findAllByAuthor(user).stream().map(TweetDTO::new).collect(toList());
   }
 
-  private User getUser(String username) {
-    User user = userRepository.findOneByUsername(username);
-    if (user != null) {
-      return user;
-    }
-    throw new UnknownUsernameException(username);
-  }
-
-  public static class UnknownUsernameException extends RuntimeException {
-    @Getter
-    private String username;
-
-    private UnknownUsernameException(String username) {
-      super(username);
-      this.username = username;
-    }
-  }
-
   public static class InvalidTweetException extends RuntimeException {
 
     private InvalidTweetException(String tweet) {

src/test/java/com/minitwitter/controller/OverviewControllerIntegrationTest.java

@@ -0,0 +1,37 @@
+package com.minitwitter.controller;
+
+import com.minitwitter.domain.dto.ErrorMessage;
+import com.minitwitter.domain.dto.UserOverviewDTO;
+import org.junit.Test;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+
+import java.util.Collections;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
+
+public class OverviewControllerIntegrationTest extends RestIntegrationTest {
+
+  @Test
+  public void overviewOfUser_onlyThatUserTweetsAreReturned() {
+    ResponseEntity<UserOverviewDTO> response = withAuthTestRestTemplate().getForEntity("/overview/{username}",
+      UserOverviewDTO.class, Collections.singletonMap("username", getUsernameOfAuthUser()));
+    assertThat(response.getStatusCode().is2xxSuccessful(), is(true));
+    UserOverviewDTO overview = response.getBody();
+    assertThat(overview.getTweets(), equalTo(ownTweetsCount()));
+    assertThat(overview.getFollowers(), equalTo(followersCount()));
+    assertThat(overview.getFollowing(), equalTo(followingUsers().length));
+  }
+
+  @Test
+  public void overviewOfUserWithWrongUsername_badRequestReturned() {
+    ResponseEntity<ErrorMessage> response = withAuthTestRestTemplate().getForEntity("/overview/{username}",
+      ErrorMessage.class, Collections.singletonMap("username", "unknown"));
+    assertThat(response.getStatusCode(), is(HttpStatus.BAD_REQUEST));
+    assertThat(response.getBody().getMessage(), containsString("unknown"));
+  }
+
+}

src/test/java/com/minitwitter/controller/RestIntegrationTest.java

@@ -12,18 +12,36 @@
 @SpringBootTest(webEnvironment = RANDOM_PORT)
 public abstract class RestIntegrationTest {
 
+  private static final String AUTH_USERNAME = "aantonop";
+  private static final int OWN_TWEETS_COUNT = 3;
+  private static final int FOLLOWERS_COUNT = 1;
+  private static final String[] FOLLOWING_USERS = new String[]{"rogerkver", "satoshiNakamoto", "SatoshiLite", "VitalikButerin"};
+  private static final String[] FOLLOWERS = new String[]{"rogerkver"};
+
   @Autowired
   private TestRestTemplate testRestTemplate;
 
   TestRestTemplate withAuthTestRestTemplate() {
-    return testRestTemplate.withBasicAuth("aantonop", "password");
+    return testRestTemplate.withBasicAuth(AUTH_USERNAME, "password");
   }
 
   String getUsernameOfAuthUser() {
-    return "aantonop";
+    return AUTH_USERNAME;
   }
 
   String[] followingUsers() {
-    return new String[]{"rogerkver", "satoshiNakamoto", "SatoshiLite", "VitalikButerin"};
+    return FOLLOWING_USERS;
+  }
+
+  String[] followers() {
+    return FOLLOWERS;
+  }
+
+  int ownTweetsCount() {
+    return OWN_TWEETS_COUNT;
+  }
+
+  int followersCount() {
+    return FOLLOWERS_COUNT;
   }
 }

src/test/java/com/minitwitter/controller/TweetControllerIntegrationTest.java

@@ -45,7 +45,7 @@ public void createTweet_tweetIsSaved() {
     Tweet fromDb = tweetRepository.findOne(tweet.getId());
     assertThat(fromDb, notNullValue());
     assertThat(fromDb.getContent(), equalTo(tweet.getContent()));
-    assertThat(fromDb.getAuthor().getUsername(), equalTo(tweet.getAuthor()));
+    assertThat(fromDb.getAuthor().getUsername(), equalTo(tweet.getAuthorUsername()));
   }
 
   @Test
@@ -76,6 +76,6 @@ public void tweetsFromUserWithWrongUsername_badRequestReturned() {
   }
 
   private List<String> extractAuthorNames(TweetDTO[] body) {
-    return Arrays.stream(body).map(TweetDTO::getAuthor).distinct().collect(toList());
+    return Arrays.stream(body).map(TweetDTO::getAuthorUsername).distinct().collect(toList());
   }
 }

src/test/java/com/minitwitter/controller/UserControllerIntegrationTest.java

@@ -21,16 +21,16 @@ public void followersRequested_allFollowersReturned() {
     ResponseEntity<UserDTO[]> response = withAuthTestRestTemplate().getForEntity("/followers", UserDTO[].class);
     assertThat(response.getStatusCode().is2xxSuccessful(), is(true));
     List<UserDTO> followers = Arrays.asList(response.getBody());
-    assertThat(followers, hasSize(1));
-    assertThat(extractUsernames(followers), contains("rogerkver"));
+    assertThat(followers, hasSize(followers().length));
+    assertThat(extractUsernames(followers), containsInAnyOrder(followers()));
   }
 
   @Test
   public void getFollowingFromFirstPage() {
     ResponseEntity<UserDTO[]> response = withAuthTestRestTemplate().getForEntity("/following", UserDTO[].class);
     assertThat(response.getStatusCode().is2xxSuccessful(), is(true));
     List<UserDTO> following = Arrays.asList(response.getBody());
-    assertThat(following, hasSize(4));
+    assertThat(following, hasSize(followingUsers().length));
     assertThat(extractUsernames(following), containsInAnyOrder(followingUsers()));
   }