Integrating Incremental Unit Test Coverage into Test Environment Coverage with Maven Surefire and JaCoCo

Background The incremental code scan data from ZLJ is used as a key criterion for release admission. While test environments already provide coverage statistics, many services rely on unit tests, and missing unit‑test coverage hampers accurate assessment. The proposed solution merges unit‑test incremental coverage into the overall test‑environment coverage.

Overall Solution

Test Platform

1. The CI platform sends the project name, branch name, and Git repository URL to the unit‑test platform, which then checks out the source code.

2. Modify the project's pom.xml to include the maven-surefire-report-plugin .

Converts generated XML reports to HTML.

Allows selection of which test classes to execute.

Supports JUnit 3, JUnit 4, and TestNG.

By default, the plugin does not run in every build lifecycle unless HTML output is needed.

Result: Opening surefire-report.htm shows the number of executed cases, pass rate, failed methods, and failure reasons.

JaCoCo Integration

3. Generate unit‑test coverage with JaCoCo by adding the parameter org.jacoco:jacoco-maven-plugin:prepare-agent to the Maven command.

4. It is recommended to add -Dmaven.test.failure.ignore=true so that test failures do not abort the build and prevent the creation of the .exec file.

After execution, a jacoco.exec file is produced in the target directory and is sent to the coverage statistics system.

Coverage Platform

1. Add a coverage‑statistics task. When the test platform receives a unit‑test execution request, it calls the coverage platform's API, providing source code address, JAR FTP address, and branch information. The platform then downloads the source, JAR, performs a code‑diff, and stores the diff results in a database.

2. Compute coverage. The article references a previous “on‑the‑fly” differential coverage approach where execution traces are collected in real time from the test server.

The new workflow allows the test platform to handle most tasks, enabling incremental unit‑test coverage statistics without modifying existing code.

At this point the entire process is complete. Readers are invited to share suggestions or alternative solutions.