Improving Code Maintainability with Sonar and Jenkins

Problem Statement

Application code growing at an uncontrollable pace, few experienced guys in the team, challenging deadlines. All these made a heady nigtmarish mix for our application from maintenance standpoint.

Issue:

I was tired of the fact that people didn't seem to realize the importance of writing comments. Files after files, methods after methods were being created with no explanation as why they were needed and what purpose they solved.

Solution: 

This time I decided to at least try and put a stop to this never ending nightmare. The solution in my eyes lied in automating code reviews instead of just manually relying on it (which was exhausting and boring). We were already using Jenkins for building our code. I (with the help of a very talented colleague), added SonarQube feature to it. 

Then I tweaked SonarQube quality rules and made comment density a critical component. Initially I have set comment density at 5%. What that means is for every 100 lines of code atleast 5 lines of comments have to be there. If this criteria is not fulfilled for any of the checked in files on a given day, the build for that day will break, requiring urgent attention from team members.

The beauty of this feature is that even if a single line has been modified in a file (say as part of a defect fix), the person checking in the file would be forced to bring the entire file's comment density at par, thereby improving application readability and maintainability.

Below screenshot explains how to configure comment density in SonarQube.

Go to Dashboards>Quality Profiles> (Your quality profile)
Search for relevant rule by entering 'comment' in Search Box. Activate 'Insufficient comment density' rule and set its Severity.