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Juan Manuel Hoyos
Juan Manuel Hoyos

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How I Got SonarCloud to Detect Test Coverage in a Spring Boot Project with JaCoCo

#springboot #java #testing #news

Recently, I ran into a pretty common problem while working on a Spring Boot project with SonarCloud: test coverage wasn't being reported correctly. Even though my tests were running fine, SonarCloud was showing 0% coverage. 🤯

After digging through the docs and trying different configurations, I finally got everything working. Here's exactly what I did, in case it helps you too.

1. Add mockito-inline dependency

One issue I had with Mockito was mocking final classes or static methods. To solve this, I added the following dependency to my pom.xml:

<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-inline</artifactId>
    <version>5.2.0</version>
    <scope>test</scope>
</dependency>
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2. Configure JaCoCo properly

The JaCoCo plugin needs to be configured correctly to generate the jacoco.xml file, which is what SonarCloud uses to calculate code coverage. Here’s the configuration I used in pom.xml:

<plugin>
    <groupId>org.jacoco</groupId>
    <artifactId>jacoco-maven-plugin</artifactId>
    <version>0.8.8</version>
    <executions>
        <execution>
            <id>prepare-agent</id>
            <goals>
                <goal>prepare-agent</goal>
            </goals>
            <configuration>
                <destFile>${project.build.directory}/jacoco.exec</destFile>
                <propertyName>surefireArgLine</propertyName>
            </configuration>
        </execution>
        <execution>
            <id>report</id>
            <phase>test</phase>
            <goals>
                <goal>report</goal>
            </goals>
            <configuration>
                <formats>
                    <format>XML</format>
                </formats>
            </configuration>
        </execution>
    </executions>
</plugin>
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You’ll also need to configure the Surefire plugin to pass the argLine property:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <configuration>
        <argLine>@{surefireArgLine} -Xshare:off</argLine>
    </configuration>
</plugin>
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3. Configure SonarCloud

To let SonarCloud find the generated report, you need to specify the path to jacoco.xml. Add this to your configuration:

sonar.coverage.jacoco.xmlReportPaths=target/site/jacoco/jacoco.xml
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You can do this either in:

  • A sonar-project.properties file, or
  • Directly in the SonarCloud web UI:
  1. Go to your project in SonarCloud.
  2. Navigate to Administration > General Settings > JaCoCo.
  3. In the "Path to XML report" field, set: 
   target/site/jacoco/jacoco.xml
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âś… The Result

After applying all these settings, I ran:

mvn clean verify
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The coverage report was generated correctly, and SonarCloud finally recognized the actual test coverage. 🎉

đź“ť Final Thoughts

Connecting JaCoCo and SonarCloud in a Spring Boot project isn’t always straightforward, especially if you're just getting started. Hopefully, this guide saves you some debugging time.

Did you run into a similar issue or find another solution? Let me know in the comments! 👇

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