If you ever had a wish to trace your algebra in a way that every method creates a new span containing method name, arguments and result, here's the easiest way I could come up with.
/* All you need to do to create a traced implementation of your algebra */
object Algebra {
implicit val aspect: Aspect.Function[Algebra, Show] = Derive.aspect
def make = AlgebraImplementation()
.weaveFunction
.mapK(Tracing.traceMethodNamesWithArgs)
}
It's based on cats-tagless AOP module
- Check out example of generated traces in
traces-full.log - Check out traced repository implementation in
PetRepository.scala - Check out Tracing implementation in
Tracing.scala
There are multiple concerns:
- What if you don't want to include all arguments? What if they're too big?
- What if arguments contain sensitive data?
You can solve this by defining custom instances of Show or some other typeclass for displaying. It adds complexity and kinda defeats the purpose. Maybe there's a better solution.
Additionally: this doesn't replace use of tracer inside of implementation if you need to add some custom info to the span, it's just a smart way of constructing spans "invisibly", so you never have to think about it again