Method Callers and Lambda

[Nico-DF]

Hi, I don't know exactly know how to report it (is it a bug? Something I don't understand? Technical limitation? etc.), So anyway, here's my problem:

My wanted rule

All calls to any invoker method must come, at some point, from a method annoted by a custom annotation (let's call it Job)

My defined rule

 @ArchTest
 public static final ArchRule methods_using_invokers_must_be_triggered_by_jobs =
      methods()
          .that().areDeclaredInClassesThat().resideInAPackage("..invoker..")
          .should(onlyBeCalledByJobsMethods())
          .because("Only job can interact with invokers");
  
  private static ArchCondition<JavaMethod> onlyBeCalledByJobsMethods() {
    return new ArchCondition<>("only be called by @Job methods") {
      @Override
      public void check(JavaMethod method, ConditionEvents events) {
        method.getCallsOfSelf().stream()
            .filter(call -> !hasJobAsCaller(call))
            .forEach(call -> events.add(SimpleConditionEvent.violated(method, call.getDescription())));
      }

      private boolean hasJobAsCaller(JavaMethodCall call) {
        if (call.getOrigin().isAnnotatedWith(Job.class)) {
          return true;
        }

        var parent = ((JavaMethod) call.getOrigin()).getCallsOfSelf();
        if (parent.isEmpty()) {
          return false;
        }
        return parent.stream().allMatch(this::hasJobAsCaller);
      }
    };
  }

This rule seems to work fine, except in one case, except if Lambda are involved.

Problematic code

I have the following code:

@Job
public void doJob() {
  lockManager.lockResourcesAndPerform(MY_RESOURCES, () -> doAction());
}

private void doAction() {
  myInvoker.doSomething();
}

If I follow this the test excecution, at some point in my recursive function,
I pass through the method doAction(), then I arrive to:

• call: (parameter of method hasJobAsCaller) ~JavaMethodCall{origin=JavaMethod(some.package.SomeClass.lambda$doJo$0()....), ...}

The JavaMethod in this case is the lambda, which itself is not annotated, so first check is false.
But if I ask for callers of this lambda (I naïvely expect the method itself to popup), I got an empty list, so in my Call Stack, I never got to encounter the method doJob() itself, hence my rule fails here

I don't know if I'm clear on the issue?
I could possibly update my rule to, instead checking the annotation, checking that the caller is in a certain package (as all method annotated by Job are on a specific package), but I would find it more natural and flexible if the rule could directly check the annotation

[hankem]

I fear that ArchUnit does unfortunately not yet recognize method references (#215) or lambda expressions (#266).

[Nico-DF]

Ok thanks, I tried to look for any open issue but I guess I missed the #266
I guess I'll close the issue to avoid clobbering Issues list