How does one write an ArchUnit specification that a constructor or method should never be called?

Certain frameworks require the empty constructor of a class to be present, e.g. a JakartaEE stateless service, but they do not have the appropriate dependencies injected. I would like to annotate these constructors with something like a DoNotUse annotation (with a reason), and then use ArchUnit to check if no one is actually using it.

Something like this:

        ArchRuleDefinition.noConstructors()
                .that()
                .areAnnotatedWith(DoNotUse.class)
                .should()
                .beCalled();

But beCalled or beUsed AFAIK does not exist. I solved it now by adding a never matching condition:

        ArchRuleDefinition.constructors()
                .that()
                .areAnnotatedWith(DoNotUse.class)
                .should()
                .onlyBeCalled()
                .byClassesThat()
                .haveSimpleName("ThisOnPurposeDoesNotMatchAnything");

How do I write a beCalled or the inverse neverBeCalled?

You can use a custom condition using convenient factory methods for ArchConditions and DescribedPredicates:

import static com.tngtech.archunit.base.DescribedPredicate.describe;
import static com.tngtech.archunit.lang.conditions.ArchConditions.be;

// ...

    ArchRule rule =  ArchRuleDefinition.noConstructors()
            .that().areAnnotatedWith(DoNotUse.class)
            .should(be(describe("called", ctor -> !ctor.getCallsOfSelf().isEmpty())));

If you want more descriptive error messages indicating where the unwanted call happens (cf. comment), you can use a custom ArchCondition like this:

import static com.tngtech.archunit.lang.SimpleConditionEvent.satisfied;

// ...

    ArchRule rule = ArchRuleDefinition.noConstructors()
            .that().areAnnotatedWith(DoNotUse.class)
            .should(new ArchCondition<JavaConstructor>("be called") {
                @Override
                public void check(JavaConstructor constructor, ConditionEvents events) {
                    constructor.getCallsOfSelf().forEach(call ->
                        events.add(satisfied(call, call.getDescription()))
                    );
                }
            });