Snippets with different design smells to learn from

broken-double-checked-locking.java

// see https://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html
private MyProfile myProfile;

public MyProfile getMyProfile(){
        if(myProfile==null){
            synchronized(this){
                if(myProfile==null){
                    myProfile=getMyProfileProc.get(userId, databaseType);
                }
            }
        }
        return myProfile;
    }

CODE-SMELLS.md

A collection of examples for typcial code smells taken from real world examples...

comment-repeating-code.coffee

  
  # An additional assignment is displayed if
  # - the slot is selected and
  # - the slot is not empty and
  # - the slot is not already assigned to the selected course
  showAdditionalAssignment: () ->
    if [email protected] then return false
    if @props.assignedCourseIds.length is 0 then return false
    if @props.assignedCourseIds.indexOf(@props.selectedCourseId) isnt -1 then return false
    true
    
  # This is a very good example of a well intended but poor method comment
  # It is a rewrite of the code into natural language!
  # Beware: Developers CAN READ code! They DON'T NEED you to rewrite in english what is written in code.
  # Comment on the intent instead of the how/what the code does.
  # Give information about WHY this code is needed (context)

goto-spaguetti.java

if (!hasReceivedSmileMessage) {
            ConversationType convType;
            Collection<MessageView> messages = loadMessages(recipientId, ctx, mCache);
            for (MessageView message : messages) {
                if (message.getMessageType() != null) {
                    convType = message.getMessageType().getConversationType();
                    if (!hasReceivedSmileMessage && convType == ConversationType.SMILE &&
                            message.getMessageDirection() == MessageDirection.INCOMING) {
                        hasReceivedSmileMessage = true;
                    } else if (convType == ConversationType.FREETEXT) {
                        if (message.getMessageDirection() == MessageDirection.INCOMING) {
                            latestMessageId = message.getMessageId();
                            hasReceivedSmileMessage = true;
                            break;
                        } else {
                            standardMessageSentCount++;
                        }
                    }
                }
            }
        }
if (!hasReceivedSmileMessage) {
            if (standardMessageSentCount > numFirstMessages) {
                log.trace("First message(s) already sent to relation {}", recipientId);
                throw new SecondMessageWithoutReplyException(
                                                             createSentMessage(0, recipientId, System.currentTimeMillis(), body, messageType),
                                                             "First message(s) already sent to relation");
            } else if (standardMessageSentCount > 1) {
                sendEmail = false;
            }
        }

unclear-domain-objects.java

public LikedTextsListResponse getLikedTexts( long relationId) {
        log.info("Get liked texts by user [{}]", relationId);
        UserContext userCtx = SessionFacade.getCurrent().getUserContext();
        if(FakeUserService.useFake()){
            ListRelationResponse relation =  FakeUserService.getFakeListRelation(userCtx.getLocale());
            if(relation!=null){
                return new LikedTextsListResponse(relation);
            }
        }
        Relation relation = relationService.getRelation(relationId, userCtx);
        Profile relProfile = profileService.getProfile(relation.getUserId(),
                relation.getDatabaseType());
        SmallProfile relSmProfile = profileService.getSmallProfile(relation.getUserId(),
                relation.getDatabaseType());
        MyProfile profile = userDataService.getMyProfile(userCtx.getUserId(),
                userCtx.getDatabaseType(), userCtx.getLocale());
        messageService.markConversationAsRead(relationId, userCtx, ConversationType.FREETEXT);
        return new LikedTextsListResponse(profile, relation, relProfile,
                relSmProfile, profile.getFreetexts());
    }