Why is code coverage zero with Scalatest, Maven and cobertura? - scala

Question

I am trying to get Cobertura to work on a really simple example project with Maven and Scala.
Here is my pom:
EDIT: Meanwhile, I found out that this pom is rather bad. If you're looking for a better example, see the one in the accepted answer.
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>sandbox</groupId>
<artifactId>sandbox</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<scala.version>2.10.4</scala.version>
</properties>
<repositories>
<repository>
<id>scala-tools.org</id>
<name>Scala-Tools Maven2 Repository</name>
<url>http://scala-tools.org/repo-releases</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>scala-tools.org</id>
<name>Scala-Tools Maven2 Repository</name>
<url>http://scala-tools.org/repo-releases</url>
</pluginRepository>
</pluginRepositories>
<dependencies>
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>${scala.version}</version>
</dependency>
<!-- Scalatest -->
<dependency>
<groupId>org.scalatest</groupId>
<artifactId>scalatest_2.10</artifactId>
<version>2.2.4</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<sourceDirectory>src/main/scala</sourceDirectory>
<testSourceDirectory>src/test/scala</testSourceDirectory>
<plugins>
<plugin>
<groupId>org.scala-tools</groupId>
<artifactId>maven-scala-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>testCompile</goal>
</goals>
</execution>
</executions>
<configuration>
<scalaVersion>${scala.version}</scalaVersion>
<args>
<arg>-target:jvm-1.5</arg>
</args>
</configuration>
</plugin>
<!-- disable surefire -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.7</version>
<configuration>
<skipTests>true</skipTests>
</configuration>
</plugin>
<!-- enable scalatest -->
<plugin>
<groupId>org.scalatest</groupId>
<artifactId>scalatest-maven-plugin</artifactId>
<version>1.0</version>
<configuration>
<reportsDirectory>${project.build.directory}/surefire-reports</reportsDirectory>
<junitxml>.</junitxml>
<filereports>WDF TestSuite.txt</filereports>
</configuration>
<executions>
<execution>
<id>test</id>
<goals>
<goal>test</goal>
</goals>
</execution>
</executions>
</plugin>
<!--enable cobertura-->
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>cobertura-maven-plugin</artifactId>
<version>2.7</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>clean</goal>
<goal>cobertura</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
<reporting>
<plugins>
<plugin>
<groupId>org.scala-tools</groupId>
<artifactId>maven-scala-plugin</artifactId>
<configuration>
<scalaVersion>${scala.version}</scalaVersion>
</configuration>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>cobertura-maven-plugin</artifactId>
<version>2.7</version>
<configuration>
<formats>
<format>xml</format>
</formats>
</configuration>
</plugin>
</plugins>
</reporting>
I disabled surefire, enabled Scalatest, and the tests do indeed get executed.
I added the Maven Cobertura plugin to the build and the reporting section of the pom. When I run
mvn clean install cobertura:cobertura -Dcobertura.report.format=xml
I do get a coverage report - which states that nothing is covered, coverage is 0%.
Now I tried various things: I played around with the executions part, I moved stuff from the build to the reporting section and vice versa, I tried different Maven goals. It was all in vain - either no report was created or it stated 0% coverage.
I even tried Scoverage! But with similar results.
So I guess I made some very basic mistake. Can anybody point me to it?

Answer 1

After a lot of trying out, I found the solution. The problem seems to have been the maven-scala-plugin dependency in the build section. But since there are so many things wrong with the pom shown above, I post here the new version, which works. (At least for the really tiny example project. With my real, bigger project, I ran into new problems with it.)
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>sandbox</groupId>
<artifactId>sandbox</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<scala.version>2.10.4</scala.version>
</properties>
<dependencies>
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>${scala.version}</version>
</dependency>
<!-- Scalatest -->
<dependency>
<groupId>org.scalatest</groupId>
<artifactId>scalatest_2.10</artifactId>
<version>2.2.4</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<sourceDirectory>src/main/scala</sourceDirectory>
<testSourceDirectory>src/test/scala</testSourceDirectory>
<plugins>
<plugin>
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>3.1.6</version>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>testCompile</goal>
</goals>
</execution>
</executions>
<configuration>
<args>
<!-- work-around for https://issues.scala-lang.org/browse/SI-8358 -->
<arg>-nobootcp</arg>
</args>
</configuration>
</plugin>
<!-- disable Surefire -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.18.1</version>
<configuration>
<skipTests>true</skipTests>
</configuration>
</plugin>
<!-- enable Scalatest -->
<plugin>
<groupId>org.scalatest</groupId>
<artifactId>scalatest-maven-plugin</artifactId>
<version>1.0</version>
<executions>
<execution>
<id>test</id>
<phase>test</phase>
<goals>
<goal>test</goal>
</goals>
</execution>
</executions>
</plugin>
<!--enable SCoverage-->
<plugin>
<groupId>org.scoverage</groupId>
<artifactId>scoverage-maven-plugin</artifactId>
<version>1.1.1</version>
<configuration>
<scalaVersion>${scala.version}</scalaVersion>
<aggregate>true</aggregate>
</configuration>
</plugin>
</plugins>
</build>
<reporting>
<plugins>
<plugin>
<groupId>org.scoverage</groupId>
<artifactId>scoverage-maven-plugin</artifactId>
<version>1.1.1</version>
<configuration>
<scalaVersion>${scala.version}</scalaVersion>
<aggregate>true</aggregate>
</configuration>
<reportSets>
<reportSet>
<reports>
<report>report</report>
</reports>
</reportSet>
</reportSets>
</plugin>
</plugins>
</reporting>
Hope this helps someone!