How to add SonarQube Code Coverage to Spring Boot

1. Overview

SonarQube is a self-managed static code analysis tool for continuous codebase inspection provided by SonarSource.

It's a popular choice used by organizations to :

• Finding and fix bugs and security vulnerabilities in code.
• Analyze code with Static Application Security Testing (SAST).
• Detect a broad range of security issues such as SQL injection vulnerabilities, cross-site scripting (XSS) code injection attacks, buffer overflows, authentication issues, cloud secrets detection and much more.
• Perform branch analysis to spot and eliminate bugs.

You can read more at https://www.sonarsource.com/lp/products/sonarqube/static-code-analysis/

In this article we will look at how to add Coverage to your Spring Boot and Java application.

2. Integrating Sonarqube to your spring boot project

• Add JaCoCo plugin to your dependencies on the pom.xml file as follows:

<dependency>
    <groupId>org.jacoco</groupId>
    <artifactId>jacoco-maven-plugin</artifactId>
    <version>0.8.11</version>
</dependency>

Work with the version of choice , you can search at Maven Central https://central.sonatype.com/artifact/org.jacoco/jacoco-maven-plugin

• Then add the following under build plugins:

<build>
   <plugins>
      <plugin>
         <groupId>org.jacoco</groupId>
         <artifactId>jacoco-maven-plugin</artifactId>
         <version>0.8.11</version>
         <executions>
            <execution>
               <id>prepare-agent</id>
               <goals>
                  <goal>prepare-agent</goal>
               </goals>
            </execution>
            <execution>
               <id>report</id>
               <goals>
                  <goal>report</goal>
               </goals>
            </execution>
         </executions>
      </plugin>
   </plugins>
</build>

There is a very good post at https://community.sonarsource.com/t/coverage-test-data-importing-jacoco-coverage-report-in-xml-format/12151 that explains importing JaCoCo coverage report in XML format.

And voila, that's all you need to do.

3. Testing

• Download and run sonarqube via docker: docker run -d -p 9000:9000 sonarqube

Then access the dashboard at : http://localhost:9000

• Back at your project directory run mvn clean install to build your code then mvn sonar:sonar to sync to sonarqube.

• Back at your sonar dashboard you will see your coverage info as follows:

4. Caveat

• To exclude packages or files from the coverage add them as following in the properties section of your pom.xml :

<properties>
   <java.version>21</java.version>
   <jacoco.version>0.8.11</jacoco.version>
   <sonar.exclusions>**/schemas/**,**/config/**</sonar.exclusions>
   <sonar.coverage.exclusions>**/schemas/**,**/config/**</sonar.coverage.exclusions>
</properties>

Run mvn clean install then mvn sonar:sonar and your coverage will update. If a devops pipeline is set, just push your changes and you will see them at your sonarqube dashboard.

• You can also add the Sonarlint plugin/extension to your IDE or Code Editor to allow you catch most of the issues before you commit or build.