Today I set up this Maven plugin to gain insight into the test coverage of my Scala code.

Amend the respective pom.xml as follows:

   <project>
    ...
    <properties>
        ...
        <scoverage.plugin.version>1.4.0</scoverage.plugin.version>
        <scoverage.scalacPluginVersion>1.4.0</scoverage.scalacPluginVersion>
        <scoverage.aggregate>true</scoverage.aggregate>
        ...
    </properties>
    ... 
    <build> 
      <plugins>
        ...
        <plugin>
          <groupId>org.scoverage</groupId>
          <artifactId>scoverage-maven-plugin</artifactId>
          <version>${scoverage.plugin.version}</version>
          <configuration>
            <scalaVersion>${scala.version}</scalaVersion>
            <scalacPluginVersion>${scoverage.scalacPluginVersion}</scalacPluginVersion>
          </configuration>
        </plugin>
        ...
      </plugins>
    </build>
    
    <reporting>
       <plugins>
         ...
         <plugin>
           <groupId>org.scoverage</groupId>
           <artifactId>scoverage-maven-plugin</artifactId>
           <version>${scoverage.plugin.version}</version>
           <reportSets>
             <reportSet>
               <reports>
                 <report>report</report>
                 <!-- or <report>integration-report</report> -->
                 <!-- or <report>report-only</report> -->
               </reports>
             </reportSet>
           </reportSets>
         </plugin>
         ...
       </plugins>
     </reporting>
     ... 
   </project>

You can then use the following commands to run the checks and generate HTML reports:

mvn scoverage:check
mvn scoverage:report

More info here: https://github.com/scoverage/scoverage-maven-plugin

Enjoy!