JUnit tests in Eclipse on Java 9 modular project

Question

I'd like to run tests with JUnit 5 on Java 9 modular project in Eclipse, with no Maven, Gradle or all that fancy stuff. So I have src/main/java path where module-info.java and module's packages live and also src/test/java where all the test classes are. Id est business as usual, prior to the Jigsaw module system. I have Eclipse Oxygen.3a (4.7.3a) an Java 10.0.1.

I've seen some video from Eclipse showing, how to add JUnit test to modular project, but this flabbergasted me deeply: they put required keyword into module-info.java of a module, binding it to JUnit module. Is that actually even correct?

I've seen also all these --patch-module / --add-reads solutions (when we're talking about working in a console) and it seems like it's the proper way to do it, but I have no idea, how to achieve that in Eclipse without binding module under test to JUnit module. Is that even possible in Eclipse (without Maven and so)?

Answer 1

I tried to solve this problem for quite a while, too. My approach is to add a filter to the source code directory for src/main/java that filters out the module-info.java. This allows to have a different module-info.java in src/test/java. It will be this one that gets copied to the output folder. This way you can run your unit tests from within the IDE and use the other one for the final build. However, you need to keep the content of the one in src/main/java updated yourself.

Right click on the project > Properties > Java Build Path > Source

Select the src/main/java entry, click Edit > Next > Exclusion Patterns > Add