We have one case in commons, there rhe -test JAR of VFS can be used by Providers to test their implementation. I did that for my custom provider, but it is a bit ugly. I think that’s mostly due to relying on some src files and also the JUnit setup when I remember correctly. But it did work, even when it’s not what maven project normally do. The test suite could be its own module, but it would probably not make it much nicer to run in that case, don’t know.
I would not expect Test jars to play nicely with application servers, OSGi bundles or JPMS for that matter. Only with shared classpath junit “deployment” Gruss Bernd -- http://bernd.eckenfels.net ________________________________ Von: Tibor Digana <tibordig...@apache.org> Gesendet: Sunday, July 4, 2021 10:19:45 PM An: Maven Users List <users@maven.apache.org> Betreff: Re: Sharing Test Dependencies I did not have time to read it all but I have to say that even the first point is bad. Many people want to share test JAR as they initially think it is a good idea. And then the problems would come. sharing stubs? This domain/project may not fit to other domain/project, and it creates dangerous cohesion. sharing testing utility classes? Maybe, it depends. It must be universal and independent of the project's domain. Do it in a separate Git project. sharing JUnit superclasses? The inheritance must be domain/business independent. It must be only a technical class. Do it in a separate Git project. T On Thu, Jul 1, 2021 at 7:15 PM Brandon Mintern <mint...@everlaw.com> wrote: > Hello all, > > I'm running up against an issue that I'm sure has come up countless times. > How can we share test dependencies in a principled way? I would like to > configure our projects such that: > > 1. For a project *P*, its tests are associated with the project, so that > `mvn install` from the project directory *p/* fails when P's tests fail. > 2. Some of P's testing functionality (e.g., stubs, testing utility > classes, JUnit superclasses) are packaged for use in the tests of other > projects* D* that depend on P. > 3. P's shared testing functionality has dependencies on P. For example, > P defines a repository interface R, and its tests define and use an > RStub > that implements R. We want to package RStub for use by D's tests. > 4. When D declares a scope:test dependency on P's testing functionality, > automatically pull in the transitive dependencies of that testing > functionality. > 5. Avoid cycles in the Maven dependency graph. > > Some things I've tried so far: > > - Create test-jars for P. This fails on #2 and #4: > - The test-jars include all of P's test classes instead of just the > testing functionality that needs to be shared for use by D's tests. > - All transitive dependencies of P's test-jar must be manually > specified with scope:test in the D's POM. > - Extract the stubs to an independent "P - Stubs" project, which P's > tests depend on. > - p-stubs depends on P. > - Stubs, testing utilities, etc. go in p-stubs/src/main/. > - P depends on p-stubs with scope:test. > - D depends on p-stubs with scope:test. > - This fails on #5: it causes a cycle in the dependency graph since P > depends on p-stubs (scope:test) and p-stubs depends on P. See > https://stackoverflow.com/questions/10174542 > - Create an independent "P - Tests" project, with P's stubs and tests. > - p-tests depends on P. > - Stubs, testing utilities, etc. go in p-tests/src/main/. > - P's tests go in p-tests/src/test/. > - D depends on p-tests with scope:test. > - This almost works but fails on #1: P's build succeeds when its > tests fail. > - This approach also seems to be fighting Maven and IDE tooling. For > example, NetBeans will automatically create p/src/test even > though we never > intend to put anything there. > > My searches so far have not turned up any complete solutions to this > problem. The maven-jar-plugin documentation has a section > < > https://maven.apache.org/plugins/maven-jar-plugin/examples/create-test-jar.html#The_preferred_way > > > that touches on this issue: > > The preferred way > > In order to let Maven resolve all test-scoped transitive dependencies you > should create a separate project. > > > 1. <project> > 2. <groupId>groupId</groupId> > 3. <artifactId>artifactId-tests</artifactId> > 4. <version>version</version> > 5. ... > 6. </project> > > > - Move the sources files from src/test/java you want to share from the > original project to the src/main/java of this project. The same type of > movement counts for the resources as well of course. > - Move the required test-scoped dependencies and from the original > project to this project and remove the scope (i.e. changing it to the > compile-scope). And yes, that means that the junit dependency (or any > other testing framework dependency) gets the default scope too. You'll > probably need to add some project specific dependencies as well to let > it > all compile again. > > Now you have your reusable *test-classes* and you can refer to it as you're > used to... > > This is along the lines of the "P - Stubs" approach I suggested above, but > it unfortunately cannot work since the stubs themselves depend on P (fails > on #3 above). > > Is there a satisfying way to solve this problem? It seems to me like any > one of the following changes would resolve the issue. > > - Allow P to depend on a separate project p-stubs with scope:test, even > though p-stubs depends on P (instead of calling it a dependency cycle). > This means that the build order would be a bit awkward: P (compile) → > p-stubs (compile) → P (test). > - Allow P to indicate that its tests are in another project p-tests. > That way, `mvn install` in p/ would continue to p-tests/ and then fail > P's > build if the tests in p-tests fail. > - Introduce a new "stubs" concept to the project model, adding a new > p/stubs directory for project P. A stubs-compile step would occur > between > compile and test-compile. The stubs and tests of D could depend on P's > stubs (perhaps automatically by virtue of D's dependency on P). > > Maybe one of these—or a better alternative—is already possible? I feel like > I must be missing something. Is something wrong with the way I'm > structuring my projects? Does Maven already provide a way to achieve this > out-of-the-box? Is there a plugin that provides something like the "stubs" > functionality? > > Thanks! > Brandon > > p.s. Sorry that my first message to the list is so long! >
