Share test resources between maven projects - maven-2

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

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>

Answer 2

Accepted answer helped me, but it's not quite accurate in case you need regular jar of same project as well. It will delete *.class files from both jars.
Settings below translates to something like:
create me 2 jars: 1 regular, 1 test;
remove *.class files, but only from test jar
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>test-jar</goal>
</goals>
<configuration>
<excludes>
<exclude>**/*.class</exclude>
</excludes>
</configuration>
</execution>
</executions>
</plugin>

Answer 3

Using maven-dependency-plugin we can put the resource needed in the right directory, only modifying the pom on dependent project is needed:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<phase>generate-test-resources</phase>
<goals>
<goal>unpack</goal>
</goals>
<configuration>
<artifactItems>
<artifactItem>
<groupId>dependeeGroupId</groupId>
<artifactId>dependeeArtifactId</artifactId>
<version>dependeeVersion</version>
<type>test-jar</type>
<outputDirectory>${project.build.directory}/test-classes</outputDirectory>
<includes>resourceNeeded.txt</includes>
<overWrite>true</overWrite>
</artifactItem>
</artifactItems>
</configuration>
</execution>
</executions>
</plugin>
type is used to get test resource
outputDirectory is used to put the resource usable in tests
Documentation here: https://maven.apache.org/plugins/maven-dependency-plugin/unpack-mojo.html

Answer 4

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.