Spans with null operation name generated if @NewSpan is used without a value

[rlubke]

Expected Behavior

Per the javadocs for NewSpan:

The name of the span which will be created. Default is the annotated method's name separated by hyphens.

The code for NewSpanTraceInterceptor has the following logic:

        AnnotationValue<NewSpan> newSpan = context.getAnnotation(NewSpan.class);
        boolean isNew = newSpan != null;
        if (!isNew) {
            return context.proceed();
        }
        String operationName = newSpan.stringValue().orElse(null);

        Tracer.SpanBuilder builder = tracer.buildSpan(operationName);

Actual Behaviour

Instead, spans are generated with a null operation name.

Steps To Reproduce

No response

Environment Information

Micronaut Tracing/Jaeger 5.0.1

Example Application

No response

Version

4.0.0