How to produce html Emma report automatically with Maven build. Useful for continuous build environments.
First, produce the report using the Emma Maven plugin like so (see http://mojo.codehaus.org/emma-maven-plugin/usage.html):
<plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>emma-maven-plugin</artifactId> <version>1.0-alpha-3</version> <inherited>true</inherited> <executions> <execution> <phase>process-classes</phase> <goals> <goal>instrument</goal> </goals> </execution> </executions> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-surefire-plugin</artifactId> <inherited>true</inherited> <configuration> <forkMode>once</forkMode> <reportFormat>txt</reportFormat> <classesDirectory>${project.build.directory}/generated-classes/emma/classes</classesDirectory> <argLine>-XX:-UseSplitVerifier</argLine> </configuration> </plugin>
Next, use the exec-maven-plugin to process the Emma output into the format you want. This example shows html and txt.
<plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>exec-maven-plugin</artifactId> <version>1.2.1</version> <executions> <execution> <phase>package</phase> <goals> <goal>exec</goal> </goals> </execution> </executions> <configuration> <executable>java</executable> <arguments> <argument>-cp</argument> <argument>${project.build.directory}/lib/*</argument> <argument>emma</argument> <argument>report</argument> <argument>-r</argument> <argument>html,txt</argument> <argument>-in</argument> <argument>${project.build.directory}/coverage.em,${basedir}/coverage.ec</argument> </arguments> </configuration> </plugin>
Note, the phase for this step is set to “package”, which comes after “process-classes” (see http://maven.apache.org/guides/introduction/introduction-to-the-lifecycle.html). Also, this example relies on the fact that I have configured maven-dependency-plugin to include my dependencies in the …/lib directory. Example:
<plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-dependency-plugin</artifactId> <version>2.6</version> <executions> <execution> <id>copy-dependencies</id> <phase>package</phase> <goals> <goal>copy-dependencies</goal> </goals> <configuration> <outputDirectory>${project.build.directory}/lib</outputDirectory> <overWriteReleases>false</overWriteReleases> <overWriteSnapshots>false</overWriteSnapshots> <overWriteIfNewer>true</overWriteIfNewer> </configuration> </execution> </executions> </plugin>
With this example, I get my html file in ${project.build.directory}/converage/index.html which I can then specify as a artifact in my continuous build environment (such as Team City) and easily access on any historical build.