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

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!