add inter-module verification based on imports

[tkachenkoas]

Hi Oliver

I've been playing a bit with modulith (in demo salespoint app), and I still not 100% understand what behavior I should expect :) I only managed to catch failures when components from not allowed modules are injected, but not when classes are used directly.

so, my use case is this: first, I define modules:

@org.moduliths.Module(displayName = "Storage") package com.myapp.storage @org.moduliths.Module(displayName = "Service", allowedDependencies = "com.myapp.storage") package com.myapp.service

and then I'll be a sneaky hacker: I won't inject anything from Service into Storage - I'll just create new ClassFromServiceLayerThatIsNotIntededForPublicUsage() - but it seems that I shouldn't be allowed to do so

am I missing some config, or this feature is missing? seems that ArchUnit provides quite a simple way to verify it. Is it in your roadmap?

[odrotbohm]

and then I'll be a sneaky hacker: I won't inject anything from Service into Storage - I'll just create new ClassFromServiceLayerThatIsNotIntededForPublicUsage() - but it seems that I shouldn't be allowed to do so

Can you elaborate on what you are doing here? Where is this class located? What types in which packages does it refer to etc.?

[tkachenkoas]

so, I'm in "storage" layer - com.myapp.storage.CommentsDAO, ['Storage' module], and suddenly I decide that I want to use com.myapp.service.CommentsServiceNotifierUtils#someStaticHelperMethod that happens to be public in 'Service' module

according to my definition of modules, I should not be able to access service module from storage module (but it's ok to access storage from service).

in java 9 modules, my code wouldn't compile - but for Modulith I'd expect @ModuleTest of 'Storage' module to fail because one of classes imports a class from module that it's not supposed to depend on

I guess, providing a example with code would be more clear :) if this is still not good enough, I'll push some example code/PR with a test that I expect to fail :)

[odrotbohm]

I think it would indeed be helpful to see a running example. An arrangement of types that you expect a validation would detect as invalid.

Just to make sure: note, that Moduliths doesn't capture violations at compile time. You either need to run an @ModuleTest or explicitly call Modules.of(…).verify();

[tkachenkoas]

@odrotbohm

sorry, my bad. can't exactly reproduce the state that I had earlier - but once I created simple project and configured some violations, I managed to have failed tests according to my expectations https://github.com/tkachenkoas/modulith-modules-playground/runs/4873831161?check_suite_focus=true