NewRelic::Agent::Instrumentation::ControllerInstrumentation .add_transaction_tracer method is missing **kwargs in its signature

[H3JFC]

Description

Considering the class Bar that looks like this:

class Bar
    def self.foo(logger: Logger.new(STDOUT))
      logger.info stuff: "logged stuff"
    end

    class << self
      include ::NewRelic::Agent::Instrumentation::ControllerInstrumentation
      add_transaction_tracer :foo, category: :task
    end
end

I get ArgumentError: wrong number of arguments (given 1, expected 0) when using the .add_transaction_tracer method on internal method foo if foo has a key word argument on ruby version 3.0.1 AND foo is invoked with key word arguments.

Expected Behavior

I expect not to get the ArgumentError.

Troubleshooting or [NR Diag]

NA

Steps to Reproduce

Run ruby bar.rb in my example project.

Your Environment

Ruby Version 3.0.1
newrelic_rpm Version 7.0.0

Additional context

To fix, consider adding **kwargs to the dynamic method signature here

It would look like so:

  class_eval <<-EOC
    def #{with_method_name}(*args, **kwargs, &block)
      perform_action_with_newrelic_trace(#{argument_list.join(',')}) do
        #{without_method_name}(*args, **kwargs, &block)
       end
    end
  EOC

[tannalynn]

@H3JFC Thank you for bringing this to our attention. We haven't received a report for this issue on this method yet. I haven't had a chance to really look into a potential fix yet, but unfortunately we won't be able to add **kwargs directly due to the range of ruby versions the agent supports (2.2-3.0) and on ruby <2.7 that results in a syntax error.
I think this is pretty similar to part of what we are needing to do in this issue #502 for add_method_tracer. I suspect we should be able to do something similar to the workaround mentioned there with ruby2_keywords. I'll put this in our backlog and talk to my team about when we can fit this in.

[beauraF]

Hello @tannalynn, same issue here at Doctolib. I think you are right, ruby2_keywords should do the trick.

edit: I opened a PR on my fork, currently testing it on our code base, before submitting it to you.