Share test resources between maven projects

Question

There is a clear solution for sharing the common test code between maven projects using test-jar goal of maven-jar-plugin plugin (see here).

I need to do the similar thing with test resources, in particular, I want test resources of project A be available in the classpath of project B during testing.

For project A one need to declare:

<!-- Package and attach test resources to the list of artifacts: -->
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-antrun-plugin</artifactId>
    <executions>
        <execution>
            <phase>package</phase>
            <goals>
                <goal>run</goal>
            </goals>
            <configuration>
                <tasks>
                    <jar destfile="${project.build.directory}/test-resources.jar">
                        <fileset dir="${project.basedir}/test-resources" />
                    </jar>
                </tasks>
            </configuration>
        </execution>
    </executions>
</plugin>
<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>build-helper-maven-plugin</artifactId>
    <executions>
        <execution>
            <phase>package</phase>
            <goals>
                <goal>attach-artifact</goal>
            </goals>
            <configuration>
                <artifacts>
                    <artifact>
                        <file>${project.build.directory}/test-resources.jar</file>
                        <type>jar</type>
                        <classifier>test-resources</classifier>
                    </artifact>
                </artifacts>
            </configuration>
        </execution>
    </executions>
</plugin>

And in project B it will be normal dependency:

<dependency>
    <groupId>myproject.groupId</groupId>
    <artifactId>myartifact</artifactId>
    <version>1.0-SNAPSHOT</version>
    <classifier>test-resources</classifier>
    <scope>test</scope>
</dependency>

Question: Should it work in all cases? Is it possible to pack resources without maven-antrun-plugin (using more 'lightweight' plugin)?

Answer 1

There is already a goal to build a test jar from maven.

Assuming you need something a little more flexible, you can use the jar plugin to package your test resources and run that goal with the main package goal with something like this.

      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-jar-plugin</artifactId>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>jar</goal>
            </goals>
            <configuration>
              <classifier>test-resources</classifier>
              <includes>
                <include>**/*.whatever-you-want</include>
              </includes>
            </configuration>
          </execution>
        </executions>
      </plugin>

Whatever you want bundled would be added to the project-name-version-test-resources.jar when the jar goal is run.

You could then include it in a project via the same dependency you use above.

Answer 2

Just use jar:test-jar and declare the resulting JAR as a dependency (refer to this guide for more details). And while I don't understand the problem of having resources and classes in this jar, you can always exclude all .class files:

<project>
  <build>
    <plugins>
     <plugin>
       <groupId>org.apache.maven.plugins</groupId>
       <artifactId>maven-jar-plugin</artifactId>
       <version>2.2</version>
       <executions>
         <execution>
           <goals>
             <goal>test-jar</goal>
           </goals>
         </execution>
       </executions>
       <configuration> 
         <excludes>
           <exclude>**/*.class</exclude>
         </excludes>
       </configuration> 
     </plugin>
    </plugins>
  </build>
</project>

And to use it:

<project>
  ...
  <dependencies>
    <dependency>
      <groupId>com.myco.app</groupId>
      <artifactId>foo</artifactId>
      <version>1.0-SNAPSHOT</version>
      <type>test-jar</type>
      <scope>test</scope>
    </dependency>
  </dependencies>
  ...
</project>