Code Coverage

This section details how PASS utilizes JaCoCo for measuring Java code coverage in PASS Core and PASS Support. Unit and Integration tests exist in PASS UI as well, but at the moment do not have any code coverage analysis being performed. We anticipate adding code coverage reports to PASS UI in the future.

Summary

PASS employs JaCoCo (Java Code Coverage Library) to measure the extent to which the project's Java code is exercised by unit and integration tests.

This process typically runs as part of the standard build cycle managed by our build tool (Maven) within the CI/CD pipeline (GitHub Actions). JaCoCo generates reports, which are then consumed by SonarQube Cloud to display coverage metrics on the project dashboard and pull request analyses. Tracking code coverage helps ensure that critical parts of the application are adequately tested, increasing confidence in code quality and reducing the risk of regressions.

Knowledge Needed / Skills Inventory

• Understanding Code Coverage Concepts

• Java 17+

• Maven build tool

Technologies Utilized

• JaCoCo

• Build Tool Maven

• GitHub Actions

• SonarQube Cloud

• SonarScanner for Maven

• SonarScanner for Maven GitHub

Technical Deep Dive

The PASS project integrates JaCoCo within the CI/CD pipeline. Achieving this involves two main steps: configuring JaCoCo reports in Maven and integrating the analysis within GitHub Actions.

Setting up the POM

Both PASS Core and PASS Support are multi-module projects which require a specific setup

• Agent Preparation: The JaCoCo Java agent is configured to run before the test execution phase. This is done using theprepare-agent goal in the parent pom.xml.

• Aggregate Report Module: A module is designated as the aggregate report module, which collects all the reports from the individual modules in the project. This module's pom.xml runs the report-aggregate goal during the verify stage. This module is named:

  • for PASS Core: jacoco-aggregate-report-pass-core

  • for PASS Support: jacoco-aggregate-report-pass-support

• Individual modules must declare the prepare-agent goal in their pom.xml

• SonarQube

  • The SonarQube Scanner is added to the parent pom.xml

  • The following properties are added to the parent pom.xml:

    • sonar.projectName

    • sonar.projectKey

    • sonar.coverage.jacoco.xmlReportPaths

• Report Generation: The report is saved in jacoco-aggregate-report-[project-name]/target/site/jacoco.xml

GitHub Actions

The integration with SonarQube also occurs during the CI/CD phase of the build process. To accomplish this integration the following steps were implemented in GitHub Actions:

• A SONAR_TOKEN secret, obtained from SonarQube Cloud, must be configured in the eclipse-pass GitHub organization secrets.

• In the snapshot.yml and ci.yml of eclipse-pass-parent the SonarQube Scanner is invoked during the mvn deploy and verify.

• The fetch-depth must have a value of 0, so that the entire Git history is fetched. If this isn't set then incomplete analysis will be performed.

Other Configurations to Note

• Using GitHub Actions requires the Automatic Analysis to be turned off on the project in SonarQube so that GitHub Actions can trigger analysis.

• A SonarQube project was created for eclipse-pass-parent. With 'Automatic Analysis' disabled in SonarCloud, all scans rely on GitHub Actions triggers. Since the primary workflows may focus only on pull request analysis, linkingeclipse-pass-parent is a necessary part of the configuration that enables analysis results for the main branch (of Core/Support) to be processed and displayed in SonarQube. Additionally, this allows the eclipse-pass-parent project itself to be analyzed for code quality and dependency vulnerabilities.

Related Information

• JaCoCo Official Website
• JaCoCo Maven Plugin Documentation
• PASS SonarQube Documentation
• SonarQube Cloud Code Coverage Integration