Proof of concept for ActiveSupport::Notifications

[hmcfletch]

This is working towards generic Skylight integration. Been wanting to take a crack at one of the skylight integrations, figured this was a good opportunity.

This is just a first pass. Opening the PR now to get feedback.

[hmcfletch]

Still needs to work in the Skylight stuff.

We could also optionally define the method based on if the instrumentation is enabled or not. Would prevent a bunch of conditional checks.

[shishirmk]

we dont have a method called to_json. I think the method we use is called serialized_json to get the JSON string representation.

I like the simple and readable approach you have taken with serializable_hash can we do the same with serialized_json?

[hmcfletch]

I was going off the original Skylight instrumenting, here, which did serializable_hash and to_json. It would be easy enough to change.

[shishirmk]

I have suggested a couple of small changes. Let me know what you think

[shishirmk]

it would be more readable if the spec were named a little elaborately. It's important to test both cases.

context 'when calling serializable_hash' do
  it 'should send a notification' do
  end
  
  it  'shouldnt send a notification' do
  end
end

[hmcfletch]

Of course. These tests were mostly just to make sure that I was actually getting notifications. :p

TDD FTW!!!

[wagenet]

For Skylight, you can make a normalizer. The normalizer is a class that extends Skylight::Normalizers::Normalizer. In the class you'll call the register method for each AS::N instrumentation you want to track. When the corresponding instrumentation is hit in AS::N, the normalize method is called. This takes 3 arguments: the current Skylight trace, the name of the AS::N instrumentation, and the AS::N payload. The expected response is an array of [category, title, description] which are all the same as what you would pass to Skylight.instrument. If, for some reason, you don't want to instrument that request, you can return :skip instead.

Hopefully, that all made sense. I really should write some proper documentation for this!

(Also, there will be some minor changes to class names for Skylight 2.0, as well as some new available hooks. However, existing code should basically work.)

[wagenet]

See an example normalizer here: https://github.com/skylightio/skylight-ruby/blob/v1.5.0/lib/skylight/normalizers/active_record/sql.rb. You can also find others in the normalizers directory.

[hmcfletch]

Would probably prefer #88 over this version.

[shishirmk]

@hmcfletch should we close this?

[hmcfletch]

yeah, this was the initial work for #88