Guice Annotation Introspection doesn't observer JacksonInject.useInput values

[josephlbarnett]

When trying to do something similar to FasterXML/jackson-databind#962 while using the jackson guice module to provide injectable values from the guice bindings, setting the useInput=OptBoolean.FALSE property is ineffective. It appears that https://github.com/FasterXML/jackson-modules-base/blob/2.12/guice/src/main/java/com/fasterxml/jackson/module/guice/GuiceAnnotationIntrospector.java#L22 always constructs a JacksonInject.Value with useInput=null, so there is no way to tell jackson the injected value should be "inject-only".

[josephlbarnett]

Have attempted to look at this here: 2.12...josephlbarnett:guice-annotation-use-input

This allows me to avoid the injection failure from FasterXML/jackson-databind#962 by setting useInput=OptBoolean.FALSE, but as seen in the attached test that fails, it appears that the injected value is always used even in the default/TRUE cases? For my specific use case that's ok, but seems unexpected / like I'm missing something about how this should work?

[cowtowncoder]

If suggesting this change, it probably would need to be a configurable setting just to make sure.

Ideally AnnotationIntrospector here should not really have to do this processing; it should usually be up to AnnotationIntrospectorPair.java to merge possible values.

Come to think it now, it looks like implementation there is the problem:

    public JacksonInject.Value findInjectableValue(AnnotatedMember m) {
        JacksonInject.Value r = _primary.findInjectableValue(m);
        return (r == null) ? _secondary.findInjectableValue(m) : r;
    }

since it probably should be doing this merging...

Would you be interested in trying a PR for jackson-databind (branch 2.12) for that?
(file is src/main/java/com/fasterxml/jackson/databind/introspect/AnnotationIntrospectorPair.java in jackson-databind)

[josephlbarnett]

ah the injected value issue appears to be similar if not the same as FasterXML/jackson-databind#2678

I can see if a change to AnnotationIntrospectorPair to merge id/useInputs from primary/secondary would help with the FasterXML/jackson-databind#962 part of the problem -- should it be something along the lines of "use the primary value, but if useInput is null/default, merge primary id with secondary useInput"?

[cowtowncoder]

@josephlbarnett yes, merging should only "fill in the blanks", and OptBoolean is designed to allow "not defined" (instead of boolean property).