I needed to move some src/test/java to src/main/java according to this recommandation from maven-jar-plugin documentation => http://maven.apache.org/plugins/maven-jar-plugin
The good configuration for maven surefire plugin is =>
org.apache.maven.plugins maven-surefire-plugin ${basedir}/src/main/java/ ${project.build.directory}/classes/ Results : Tests run: 20, Failures: 0, Errors: 0, Skipped: 0