JACT - Java Absolute Coverage Tracker

What is JACT?

JACT is a Maven plugin for my master's thesis that generates a complete code coverage report of a Java project using Maven. The generated report includes the conventional project coverage in addition to the coverage of the entire dependency tree to be manually investigated in the human-readable HTML format or used for additional purposes via the XML format. JACT uses the JaCoCo CLI to generate the coverage report on the packaged Uber-jar. Thereafter, it augments the unorganized package report by resolving the package dependency heritage and calculates the coverage of all dependencies.

Current prerequisites:

• Required to use JaCoCo
• Use either the Maven Shade Plugin to create an Uber-jar (including all the dependencies along with their transitive dependencies). Example provided under 'Using JACT'.
• Resulting Uber-jar has to be placed under ./target/

Building the test project and inspecting its coverage report:

• Clone this repo and build the project from the root folder:

  mvn clean install
  

• Navigate into the root of the test project: ./src/main/it/test-project and again execute:

  mvn clean install
  

The report will now be located under the test project /target/jact-report where its index.html file is a good place to start.

Using JACT:

After fulfilling the prerequsites in your project, clone this repo and execute mvn clean install.

For JACT to create a complete coverage report you need to package your project separately as a Uber-jar. This is done with the Maven Shade Plugin. Add this minimal configuration to the pom.xml file in your project:

<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>3.2.4</version> <!-- Adjust version if needed -->
<executions>
    <execution>
        <phase>package</phase>
        <goals>
            <goal>shade</goal>
        </goals>
        <configuration>
            <shadedArtifactAttached>true</shadedArtifactAttached>
        </configuration>
    </execution>
</executions>
</plugin>

Now just add the JACT plugin to the pom.xml file in your project:

<plugin>
    <groupId>java.absolute.coverage.tracker</groupId>
    <artifactId>jact</artifactId>
    <version>1.0</version> <!-- Adjust version if needed -->
    <executions>
        <execution>
            <goals>
                <goal>${report-format}</goal>
            </goals>
        </execution>
    </executions>
</plugin>

The property ${report-format} can take one of the following values depending on the desired report format:

• html-report Generates the HTML report.
• xml-report Generates the XML report.
• combined-report Generates both the HTML and XML report.

JACT creates the report during the install-phase since it requires a packaged Uber-jar. Executing mvn clean install in your project will create a jact-report directory under ./target/jact-report.

Custom Maven-Shade-Plugin jar name:
If your project packages a Uber-jar under a custom name the custom name can be provided by adding this to your JACT configuration:

<configuration>
  <shadedJarName>${Custom-Jar-Name}</shadedJarName> <!-- Without .jar -->
</configuration>

Example JACT configuration with a custom jar-name:

<plugin>
    <groupId>java.absolute.coverage.tracker</groupId>
    <artifactId>jact</artifactId>
    <version>1.0</version> <!-- Adjust version if needed -->
    <configuration>
      <shadedJarName>jact-example</shadedJarName> <!-- Without .jar -->
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>html-report</goal>
            </goals>
        </execution>
    </executions>
</plugin>

Report Formats Details

JACT supports both HTML and XML report formats. The intended usage for the HTML version is to create a human-readable format that is quickly interpreted. The XML format is intended as a raw report format for any purpose, which could for instance be to get dependency coverage down to the method level for removing unwanted bytecode.

The XML report structure can be seen in the following example:

<report name="JACT Coverage Report (Generated with JaCoCo)">
    <group name="Dependencies">
      <group name="dependencyId">
        <package name="packageName">
          <!-- Package usage info -->
          <!-- Total Package Coverage -->
        </package>
        <!-- Rest the packages in the dependency -->
            <!-- ... -->
      </group>
      <!-- Rest of the dependencies-->
        <!-- ... -->
      <!-- Dependency Coverage Total -->
    </group>
    <group name="Project Packages">
      <package name="packageName">
        <!-- Package usage info -->
        <!-- Total Package Coverage -->
      </package>
      <!-- Rest of the project packages-->
        <!-- ... -->
      <!-- Project Coverage Total -->
    </group>
  <!-- Overall Coverage Total -->
</report>