Inject Groovy into existing Maven Java Project - eclipse

Question

I have been maintaining a maven java project for year.
Recently, I learned Ruby and asked why haven't these nice features (of Ruby) existed in Java, and I am so happy to find Groovy the answer. It's already out there for more than 6 years and what a shame I didn't know about it sooner.
Now come to the story:
I have a lot of java code written already, organized in folder structures follow maven default convention (src/main/java for logic & src/test/java for test)
Now, I want to write some new stuff in Groovy, so I guess I should create src/main/groovy for groovy logic and src/test/groovy for test. However, both mvn eclipse:eclipse and the latest m2eclipse only understand and include src/main/groovy as source code folder of the generated eclipse project, and don't not recognize src/test/groovy at all.
Is this the correct behavior? Or am I missed any thing?
By the way, here is the gmaven plugin configured inside my POM:
<build>
...
<plugins>
...
<plugin>
<groupId>org.codehaus.gmaven</groupId>
<artifactId>gmaven-plugin</artifactId>
<version>1.2</version>
<executions>
<execution>
<goals>
<goal>generateStubs</goal>
<goal>compile</goal>
<goal>generateTestStubs</goal>
<goal>testCompile</goal>
</goals>
<configuration>
<providerSelection>1.7</providerSelection>
</configuration>
</execution>
</executions>
<dependencies>
<dependency>
<groupId>org.codehaus.gmaven.runtime</groupId>
<artifactId>gmaven-runtime-1.7</artifactId>
<version>1.2</version>
<scope>compile</scope>
<exclusions>
<exclusion>
<artifactId>groovy-all</artifactId>
<groupId>org.codehaus.groovy</groupId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.codehaus.groovy</groupId>
<artifactId>groovy-all</artifactId>
<version>1.7.0</version>
<scope>compile</scope>
</dependency>
</dependencies>
<configuration>
<providerSelection>1.7</providerSelection>
</configuration>
</plugin>
...
</plugins>
...
</build>

Answer 1

You may find that you have better luck with new version of m2eclipse instead of eclipse:eclipse. Either way, once your project is in eclipse, navigate your src/{main,test}/ folder, right-click and choose Build Path and "User as Source Folder".

Answer 2

Using eclipse can be more comfortable :
Import your project into eclipse as "Maven project"
1) go to Eclipse Marketplace & install groovy compiler
2)right-click on project and configure it as groovy project
3)result :