SonarQube (https://www.sonarqube.org/) is a tool that scans your code and does a quality check. A set of rules are applied to your code and every time you break a rule, SonarQube will report it and add it to the technical debt. A rule can be simple, such as a missing semi-colon at the end of a JavaScript line. That should be a few seconds fix. Another rule can be more difficult, such as that the complexity of a function (nested loop and if statements and the lines of code add to the complexity) should not be greater than a certain value. SonarQube has a default set of rules, but you can roll out your own. In this book, we are going to see SonarQube with HTML, CSS, JavaScript, and C#, but SonarQube supports many languages, such as Java, VB.NET, SQL, Haskell, PHP, and many more.




















































