PROBLEM

When running mvn clean test, Maven Surefire Plugin doesn’t pick up *Spec.groovy test files.

SOLUTION

By default, Maven Surefire Plugin is configured to execute test files with the following patterns: **/Test*.java, **/*Test.java and **/*TestCase.java.

To fix this, we need to modify the inclusion list for this plugin. Since both Java and Groovy files get compiled down to *.class, it is probably easier to just include *.class instead of *.java or *.groovy.

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>2.17</version>
    <configuration>
        <includes>
            <include>**/Test*.class</include>
            <include>**/*Test.class</include>
            <include>**/*TestCase.class</include>
            <include>**/*Spec.class</include>
        </includes>
    </configuration>
</plugin>